diff --git a/IMPLEMENTATION_COVERAGE.md b/IMPLEMENTATION_COVERAGE.md
index d4c250277..50858d4ff 100644
--- a/IMPLEMENTATION_COVERAGE.md
+++ b/IMPLEMENTATION_COVERAGE.md
@@ -2051,37 +2051,37 @@
 
 ## efs
 <details>
-<summary>23% implemented</summary>
+<summary>56% implemented</summary>
 
-- [ ] create_access_point
+- [X] create_access_point
 - [X] create_file_system
 - [X] create_mount_target
 - [ ] create_replication_configuration
 - [ ] create_tags
-- [ ] delete_access_point
+- [X] delete_access_point
 - [X] delete_file_system
 - [ ] delete_file_system_policy
 - [X] delete_mount_target
 - [ ] delete_replication_configuration
 - [ ] delete_tags
-- [ ] describe_access_points
+- [X] describe_access_points
 - [ ] describe_account_preferences
 - [X] describe_backup_policy
 - [ ] describe_file_system_policy
 - [X] describe_file_systems
-- [ ] describe_lifecycle_configuration
-- [ ] describe_mount_target_security_groups
+- [X] describe_lifecycle_configuration
+- [X] describe_mount_target_security_groups
 - [X] describe_mount_targets
 - [ ] describe_replication_configurations
 - [ ] describe_tags
-- [ ] list_tags_for_resource
-- [ ] modify_mount_target_security_groups
+- [X] list_tags_for_resource
+- [X] modify_mount_target_security_groups
 - [ ] put_account_preferences
 - [ ] put_backup_policy
 - [ ] put_file_system_policy
-- [ ] put_lifecycle_configuration
-- [ ] tag_resource
-- [ ] untag_resource
+- [X] put_lifecycle_configuration
+- [X] tag_resource
+- [X] untag_resource
 - [ ] update_file_system
 </details>
 
diff --git a/docs/docs/services/efs.rst b/docs/docs/services/efs.rst
index 9cd1ed5ac..47d76e667 100644
--- a/docs/docs/services/efs.rst
+++ b/docs/docs/services/efs.rst
@@ -27,7 +27,7 @@ efs
 
 |start-h3| Implemented features for this service |end-h3|
 
-- [ ] create_access_point
+- [X] create_access_point
 - [X] create_file_system
   Create a new EFS File System Volume.
 
@@ -45,7 +45,7 @@ efs
 
 - [ ] create_replication_configuration
 - [ ] create_tags
-- [ ] delete_access_point
+- [X] delete_access_point
 - [X] delete_file_system
   Delete the file system specified by the given file_system_id.
 
@@ -65,7 +65,11 @@ efs
 
 - [ ] delete_replication_configuration
 - [ ] delete_tags
-- [ ] describe_access_points
+- [X] describe_access_points
+  
+        Pagination is not yet implemented
+        
+
 - [ ] describe_account_preferences
 - [X] describe_backup_policy
 - [ ] describe_file_system_policy
@@ -75,26 +79,23 @@ efs
         https://docs.aws.amazon.com/efs/latest/ug/API_DescribeFileSystems.html
         
 
-- [ ] describe_lifecycle_configuration
-- [ ] describe_mount_target_security_groups
+- [X] describe_lifecycle_configuration
+- [X] describe_mount_target_security_groups
 - [X] describe_mount_targets
-  Describe the mount targets given a mount target ID or a file system ID.
-
-        Note that as of this writing access points, and thus access point IDs are not
-        supported.
+  Describe the mount targets given an access point ID, mount target ID or a file system ID.
 
         https://docs.aws.amazon.com/efs/latest/ug/API_DescribeMountTargets.html
         
 
 - [ ] describe_replication_configurations
 - [ ] describe_tags
-- [ ] list_tags_for_resource
-- [ ] modify_mount_target_security_groups
+- [X] list_tags_for_resource
+- [X] modify_mount_target_security_groups
 - [ ] put_account_preferences
 - [ ] put_backup_policy
 - [ ] put_file_system_policy
-- [ ] put_lifecycle_configuration
-- [ ] tag_resource
-- [ ] untag_resource
+- [X] put_lifecycle_configuration
+- [X] tag_resource
+- [X] untag_resource
 - [ ] update_file_system
 
diff --git a/moto/efs/exceptions.py b/moto/efs/exceptions.py
index 7bc8c1c19..a1f36c789 100644
--- a/moto/efs/exceptions.py
+++ b/moto/efs/exceptions.py
@@ -1,10 +1,19 @@
-from moto.core.exceptions import RESTError
+from moto.core.exceptions import JsonRESTError
 
 
-class EFSError(RESTError):
+class EFSError(JsonRESTError):
     pass
 
 
+class AccessPointNotFound(EFSError):
+    code = 404
+
+    def __init__(self, access_point_id):
+        super().__init__(
+            "AccessPointNotFound", f"Access Point {access_point_id} does not exist."
+        )
+
+
 class FileSystemAlreadyExists(EFSError):
     code = 409
 
@@ -13,7 +22,7 @@ class FileSystemAlreadyExists(EFSError):
             "FileSystemAlreadyExists",
             "File system with {} already exists.".format(creation_token),
             *args,
-            **kwargs
+            **kwargs,
         )
 
 
@@ -25,7 +34,7 @@ class FileSystemNotFound(EFSError):
             "FileSystemNotFound",
             "File system {} does not exist.".format(file_system_id),
             *args,
-            **kwargs
+            **kwargs,
         )
 
 
@@ -51,7 +60,7 @@ class MountTargetNotFound(EFSError):
             "MountTargetNotFound",
             "Mount target '{}' does not exist.".format(mount_target_id),
             *args,
-            **kwargs
+            **kwargs,
         )
 
 
@@ -77,7 +86,7 @@ class SubnetNotFound(EFSError):
             "SubnetNotFound",
             "The subnet ID '{}' does not exist".format(subnet_id),
             *args,
-            **kwargs
+            **kwargs,
         )
 
 
@@ -89,7 +98,7 @@ class SecurityGroupNotFound(EFSError):
             "SecurityGroupNotFound",
             "The SecurityGroup ID '{}' does not exist".format(security_group_id),
             *args,
-            **kwargs
+            **kwargs,
         )
 
 
diff --git a/moto/efs/models.py b/moto/efs/models.py
index 1a3650134..b4d1a2800 100644
--- a/moto/efs/models.py
+++ b/moto/efs/models.py
@@ -9,7 +9,7 @@ import time
 from copy import deepcopy
 from hashlib import md5
 
-from moto.core import ACCOUNT_ID, BaseBackend, CloudFormationModel
+from moto.core import ACCOUNT_ID, BaseBackend, BaseModel, CloudFormationModel
 from moto.core.utils import (
     camelcase_to_underscores,
     get_random_hex,
@@ -19,6 +19,7 @@ from moto.core.utils import (
 from moto.ec2 import ec2_backends
 from moto.ec2.exceptions import InvalidSubnetIdError
 from moto.efs.exceptions import (
+    AccessPointNotFound,
     BadRequest,
     FileSystemAlreadyExists,
     FileSystemInUse,
@@ -30,6 +31,7 @@ from moto.efs.exceptions import (
     SecurityGroupNotFound,
     SecurityGroupLimitExceeded,
 )
+from moto.utilities.tagging_service import TaggingService
 
 
 def _lookup_az_id(az_name):
@@ -40,6 +42,48 @@ def _lookup_az_id(az_name):
             return zone.zone_id
 
 
+class AccessPoint(BaseModel):
+    def __init__(
+        self,
+        region_name,
+        client_token,
+        file_system_id,
+        name,
+        posix_user,
+        root_directory,
+        context,
+    ):
+        self.access_point_id = get_random_hex(8)
+        self.access_point_arn = "arn:aws:elasticfilesystem:{region}:{user_id}:access-point/fsap-{file_system_id}".format(
+            region=region_name, user_id=ACCOUNT_ID, file_system_id=self.access_point_id
+        )
+        self.client_token = client_token
+        self.file_system_id = file_system_id
+        self.name = name
+        self.posix_user = posix_user
+
+        if not root_directory:
+            root_directory = {"Path": "/"}
+
+        self.root_directory = root_directory
+        self.context = context
+
+    def info_json(self):
+        tags = self.context.list_tags_for_resource(self.access_point_id)
+        return {
+            "ClientToken": self.client_token,
+            "Name": self.name,
+            "Tags": tags,
+            "AccessPointId": self.access_point_id,
+            "AccessPointArn": self.access_point_arn,
+            "FileSystemId": self.file_system_id,
+            "PosixUser": self.posix_user,
+            "RootDirectory": self.root_directory,
+            "OwnerId": ACCOUNT_ID,
+            "LifeCycleState": "available",
+        }
+
+
 class FileSystem(CloudFormationModel):
     """A model for an EFS File System Volume."""
 
@@ -48,16 +92,16 @@ class FileSystem(CloudFormationModel):
         region_name,
         creation_token,
         file_system_id,
-        performance_mode="generalPurpose",
-        encrypted=False,
-        kms_key_id=None,
-        throughput_mode="bursting",
-        provisioned_throughput_in_mibps=None,
-        availability_zone_name=None,
-        backup=False,
+        context,
+        performance_mode,
+        encrypted,
+        kms_key_id,
+        throughput_mode,
+        provisioned_throughput_in_mibps,
+        availability_zone_name,
+        backup,
         lifecycle_policies=None,
         file_system_policy=None,
-        tags=None,
     ):
         if availability_zone_name:
             backup = True
@@ -66,31 +110,20 @@ class FileSystem(CloudFormationModel):
 
         # Save given parameters
         self.creation_token = creation_token
-        self.performance_mode = performance_mode
-        self.encrypted = encrypted
+        self.performance_mode = performance_mode or "generalPurpose"
+        self.encrypted = encrypted or False
         self.kms_key_id = kms_key_id
-        self.throughput_mode = throughput_mode
+        self.throughput_mode = throughput_mode or "bursting"
         self.provisioned_throughput_in_mibps = provisioned_throughput_in_mibps
         self.availability_zone_name = availability_zone_name
         self.availability_zone_id = None
         if self.availability_zone_name:
             self.availability_zone_id = _lookup_az_id(self.availability_zone_name)
         self._backup = backup
-        self.lifecycle_policies = lifecycle_policies
+        self.lifecycle_policies = lifecycle_policies or []
         self.file_system_policy = file_system_policy
 
-        # Validate tag structure.
-        if tags is None:
-            self.tags = []
-        else:
-            if (
-                not isinstance(tags, list)
-                or not all(isinstance(tag, dict) for tag in tags)
-                or not all(set(tag.keys()) == {"Key", "Value"} for tag in tags)
-            ):
-                raise ValueError("Invalid tags: {}".format(tags))
-            else:
-                self.tags = tags
+        self._context = context
 
         # Generate AWS-assigned parameters
         self.file_system_id = file_system_id
@@ -135,6 +168,7 @@ class FileSystem(CloudFormationModel):
             for k, v in self.__dict__.items()
             if not k.startswith("_")
         }
+        ret["Tags"] = self._context.list_tags_for_resource(self.file_system_id)
         ret["SizeInBytes"] = self.size_in_bytes
         ret["NumberOfMountTargets"] = self.number_of_mount_targets
         return ret
@@ -318,9 +352,11 @@ class EFSBackend(BaseBackend):
         super().__init__()
         self.region_name = region_name
         self.creation_tokens = set()
+        self.access_points = dict()
         self.file_systems_by_id = {}
         self.mount_targets_by_id = {}
         self.next_markers = {}
+        self.tagging_service = TaggingService()
 
     def reset(self):
         # preserve region
@@ -331,7 +367,8 @@ class EFSBackend(BaseBackend):
     def _mark_description(self, corpus, max_items):
         if max_items < len(corpus):
             new_corpus = corpus[max_items:]
-            new_hash = md5(json.dumps(new_corpus).encode("utf-8"))
+            new_corpus_dict = [c.info_json() for c in new_corpus]
+            new_hash = md5(json.dumps(new_corpus_dict).encode("utf-8"))
             next_marker = new_hash.hexdigest()
             self.next_markers[next_marker] = new_corpus
         else:
@@ -342,7 +379,18 @@ class EFSBackend(BaseBackend):
     def ec2_backend(self):
         return ec2_backends[self.region_name]
 
-    def create_file_system(self, creation_token, **params):
+    def create_file_system(
+        self,
+        creation_token,
+        performance_mode,
+        encrypted,
+        kms_key_id,
+        throughput_mode,
+        provisioned_throughput_in_mibps,
+        availability_zone_name,
+        backup,
+        tags,
+    ):
         """Create a new EFS File System Volume.
 
         https://docs.aws.amazon.com/efs/latest/ug/API_CreateFileSystem.html
@@ -363,12 +411,22 @@ class EFSBackend(BaseBackend):
             self.region_name,
             creation_token,
             fsid,
-            **{k: v for k, v in params.items() if v is not None}
+            context=self,
+            performance_mode=performance_mode,
+            encrypted=encrypted,
+            kms_key_id=kms_key_id,
+            throughput_mode=throughput_mode,
+            provisioned_throughput_in_mibps=provisioned_throughput_in_mibps,
+            availability_zone_name=availability_zone_name,
+            backup=backup,
         )
+        self.tag_resource(fsid, tags)
         self.creation_tokens.add(creation_token)
         return self.file_systems_by_id[fsid]
 
-    def describe_file_systems(self, marker, max_items, creation_token, file_system_id):
+    def describe_file_systems(
+        self, marker=None, max_items=10, creation_token=None, file_system_id=None
+    ):
         """Describe all the EFS File Systems, or specific File Systems.
 
         https://docs.aws.amazon.com/efs/latest/ug/API_DescribeFileSystems.html
@@ -383,7 +441,7 @@ class EFSBackend(BaseBackend):
             corpus = []
             for fs in self.file_systems_by_id.values():
                 if fs.creation_token == creation_token:
-                    corpus.append(fs.info_json())
+                    corpus.append(fs)
         elif file_system_id:
             # Handle the case that a file_system_id is given.
             if file_system_id not in self.file_systems_by_id:
@@ -396,7 +454,7 @@ class EFSBackend(BaseBackend):
             corpus = self.next_markers[marker]
         else:
             # Handle the vanilla case.
-            corpus = [fs.info_json() for fs in self.file_systems_by_id.values()]
+            corpus = [fs for fs in self.file_systems_by_id.values()]
 
         # Handle the max_items parameter.
         file_systems = corpus[:max_items]
@@ -445,42 +503,40 @@ class EFSBackend(BaseBackend):
     def describe_mount_targets(
         self, max_items, file_system_id, mount_target_id, access_point_id, marker
     ):
-        """Describe the mount targets given a mount target ID or a file system ID.
-
-        Note that as of this writing access points, and thus access point IDs are not
-        supported.
+        """Describe the mount targets given an access point ID, mount target ID or a file system ID.
 
         https://docs.aws.amazon.com/efs/latest/ug/API_DescribeMountTargets.html
         """
         # Restrict the possible corpus of results based on inputs.
         if not (bool(file_system_id) ^ bool(mount_target_id) ^ bool(access_point_id)):
             raise BadRequest("Must specify exactly one mutually exclusive parameter.")
-        elif file_system_id:
+
+        if access_point_id:
+            file_system_id = self.access_points[access_point_id].file_system_id
+
+        if file_system_id:
             # Handle the case that a file_system_id is given.
             if file_system_id not in self.file_systems_by_id:
                 raise FileSystemNotFound(file_system_id)
             corpus = [
-                mt.info_json()
+                mt
                 for mt in self.file_systems_by_id[file_system_id].iter_mount_targets()
             ]
         elif mount_target_id:
             if mount_target_id not in self.mount_targets_by_id:
                 raise MountTargetNotFound(mount_target_id)
             # Handle mount target specification case.
-            corpus = [self.mount_targets_by_id[mount_target_id].info_json()]
-        else:
-            # We don't handle access_point_id's yet.
-            assert False, "Moto does not yet support EFS access points."
+            corpus = [self.mount_targets_by_id[mount_target_id]]
 
         # Handle the case that a marker is given. Note that the handling is quite
         # different from that in describe_file_systems.
         if marker is not None:
             if marker not in self.next_markers:
                 raise BadRequest("Invalid Marker")
-            corpus_mtids = {m["MountTargetId"] for m in corpus}
-            marked_mtids = {m["MountTargetId"] for m in self.next_markers[marker]}
+            corpus_mtids = {m.mount_target_id for m in corpus}
+            marked_mtids = {m.mount_target_id for m in self.next_markers[marker]}
             mt_ids = corpus_mtids & marked_mtids
-            corpus = [self.mount_targets_by_id[mt_id].info_json() for mt_id in mt_ids]
+            corpus = [self.mount_targets_by_id[mt_id] for mt_id in mt_ids]
 
         # Handle the max_items parameter.
         mount_targets = corpus[:max_items]
@@ -529,5 +585,72 @@ class EFSBackend(BaseBackend):
             raise PolicyNotFound("None")
         return backup_policy
 
+    def put_lifecycle_configuration(self, file_system_id, policies):
+        _, fss = self.describe_file_systems(file_system_id=file_system_id)
+        file_system = fss[0]
+        file_system.lifecycle_policies = policies
+
+    def describe_lifecycle_configuration(self, file_system_id):
+        _, fss = self.describe_file_systems(file_system_id=file_system_id)
+        file_system = fss[0]
+        return file_system.lifecycle_policies
+
+    def describe_mount_target_security_groups(self, mount_target_id):
+        if mount_target_id not in self.mount_targets_by_id:
+            raise MountTargetNotFound(mount_target_id)
+
+        mount_target = self.mount_targets_by_id[mount_target_id]
+        return mount_target.security_groups
+
+    def modify_mount_target_security_groups(self, mount_target_id, security_groups):
+        if mount_target_id not in self.mount_targets_by_id:
+            raise MountTargetNotFound(mount_target_id)
+
+        mount_target = self.mount_targets_by_id[mount_target_id]
+        mount_target.security_groups = security_groups
+
+        self.ec2_backend.modify_network_interface_attribute(
+            eni_id=mount_target.network_interface_id, group_ids=security_groups
+        )
+
+    def create_access_point(
+        self, client_token, tags, file_system_id, posix_user, root_directory
+    ):
+        name = next((tag["Value"] for tag in tags if tag["Key"] == "Name"), None)
+        access_point = AccessPoint(
+            self.region_name,
+            client_token,
+            file_system_id,
+            name,
+            posix_user,
+            root_directory,
+            context=self,
+        )
+        self.tagging_service.tag_resource(access_point.access_point_id, tags)
+        self.access_points[access_point.access_point_id] = access_point
+        return access_point
+
+    def describe_access_points(self, access_point_id):
+        """
+        Pagination is not yet implemented
+        """
+        if access_point_id:
+            if access_point_id not in self.access_points:
+                raise AccessPointNotFound(access_point_id)
+            return [self.access_points[access_point_id]]
+        return self.access_points.values()
+
+    def delete_access_point(self, access_point_id):
+        self.access_points.pop(access_point_id, None)
+
+    def list_tags_for_resource(self, resource_id):
+        return self.tagging_service.list_tags_for_resource(resource_id)["Tags"]
+
+    def tag_resource(self, resource_id, tags):
+        self.tagging_service.tag_resource(resource_id, tags)
+
+    def untag_resource(self, resource_id, tag_keys):
+        self.tagging_service.untag_resource_using_names(resource_id, tag_keys)
+
 
 efs_backends = BackendDict(EFSBackend, "efs")
diff --git a/moto/efs/responses.py b/moto/efs/responses.py
index 6fc05624a..4fb350772 100644
--- a/moto/efs/responses.py
+++ b/moto/efs/responses.py
@@ -23,7 +23,7 @@ class EFSResponse(BaseResponse):
         )
         availability_zone_name = self._get_param("AvailabilityZoneName")
         backup = self._get_param("Backup")
-        tags = self._get_param("Tags")
+        tags = self._get_param("Tags") or []
         resource = self.efs_backend.create_file_system(
             creation_token=creation_token,
             performance_mode=performance_mode,
@@ -51,7 +51,7 @@ class EFSResponse(BaseResponse):
             creation_token=creation_token,
             file_system_id=file_system_id,
         )
-        resp_json = {"FileSystems": file_systems}
+        resp_json = {"FileSystems": [fs.info_json() for fs in file_systems]}
         if marker:
             resp_json["Marker"] = marker
         if next_marker:
@@ -87,7 +87,7 @@ class EFSResponse(BaseResponse):
             access_point_id=access_point_id,
             marker=marker,
         )
-        resp_json = {"MountTargets": mount_targets}
+        resp_json = {"MountTargets": [mt.info_json() for mt in mount_targets]}
         if marker:
             resp_json["Marker"] = marker
         if next_marker:
@@ -109,3 +109,80 @@ class EFSResponse(BaseResponse):
         backup_policy = self.efs_backend.describe_backup_policy(file_system_id)
         resp = {"BackupPolicy": backup_policy}
         return json.dumps(resp), {"Content-Type": "application/json"}
+
+    def put_lifecycle_configuration(self):
+        file_system_id = self._get_param("FileSystemId")
+        policies = self._get_param("LifecyclePolicies")
+        self.efs_backend.put_lifecycle_configuration(file_system_id, policies)
+        return json.dumps({"LifecyclePolicies": policies}), {
+            "Content-Type": "application/json"
+        }
+
+    def describe_lifecycle_configuration(self):
+        file_system_id = self._get_param("FileSystemId")
+        policies = self.efs_backend.describe_lifecycle_configuration(file_system_id)
+        return json.dumps({"LifecyclePolicies": policies}), {
+            "Content-Type": "application/json"
+        }
+
+    def describe_mount_target_security_groups(self):
+        mount_target_id = self._get_param("MountTargetId")
+        security_groups = self.efs_backend.describe_mount_target_security_groups(
+            mount_target_id
+        )
+        return json.dumps({"SecurityGroups": security_groups}), {
+            "Content-Type": "application/json"
+        }
+
+    def modify_mount_target_security_groups(self):
+        mount_target_id = self._get_param("MountTargetId")
+        security_groups = self._get_param("SecurityGroups")
+        self.efs_backend.modify_mount_target_security_groups(
+            mount_target_id, security_groups
+        )
+        return "{}", {"Content-Type": "application/json"}
+
+    def create_access_point(self):
+        client_token = self._get_param("ClientToken")
+        tags = self._get_param("Tags") or []
+        file_system_id = self._get_param("FileSystemId")
+        posix_user = self._get_param("PosixUser")
+        root_directory = self._get_param("RootDirectory")
+        access_point = self.efs_backend.create_access_point(
+            client_token,
+            tags=tags,
+            file_system_id=file_system_id,
+            posix_user=posix_user,
+            root_directory=root_directory,
+        )
+        return json.dumps(access_point.info_json()), {
+            "Content-Type": "application/json"
+        }
+
+    def describe_access_points(self):
+        access_point_id = self._get_param("AccessPointId")
+        access_points = self.efs_backend.describe_access_points(access_point_id)
+        resp = [ap.info_json() for ap in access_points]
+        return json.dumps({"AccessPoints": resp}), {"Content-Type": "application/json"}
+
+    def delete_access_point(self):
+        access_point_id = self._get_param("AccessPointId")
+        self.efs_backend.delete_access_point(access_point_id)
+        return "{}", {"Content-Type": "application/json"}
+
+    def list_tags_for_resource(self):
+        resource_id = self._get_param("ResourceId")
+        tags = self.efs_backend.list_tags_for_resource(resource_id)
+        return json.dumps({"Tags": tags}), {"Content-Type": "application/json"}
+
+    def tag_resource(self):
+        resource_id = self._get_param("ResourceId")
+        tags = self._get_param("Tags")
+        self.efs_backend.tag_resource(resource_id, tags)
+        return "{}", {"Content-Type": "application/json"}
+
+    def untag_resource(self):
+        resource_id = self._get_param("ResourceId")
+        tag_keys = self.querystring.get("tagKeys", [])
+        self.efs_backend.untag_resource(resource_id, tag_keys)
+        return "{}", {"Content-Type": "application/json"}
diff --git a/moto/efs/urls.py b/moto/efs/urls.py
index 052e1c942..7cc53f31b 100644
--- a/moto/efs/urls.py
+++ b/moto/efs/urls.py
@@ -11,9 +11,14 @@ response = EFSResponse()
 
 url_paths = {
     "{0}/.*?$": response.dispatch,
+    "/2015-02-01/access-points": response.dispatch,
+    "/2015-02-01/access-points/<access_point_id>": response.dispatch,
     "/2015-02-01/file-systems": response.dispatch,
     "/2015-02-01/file-systems/<file_system_id>": response.dispatch,
     "/2015-02-01/file-systems/<file_system_id>/backup-policy": response.dispatch,
+    "/2015-02-01/file-systems/<file_system_id>/lifecycle-configuration": response.dispatch,
     "/2015-02-01/mount-targets": response.dispatch,
     "/2015-02-01/mount-targets/<mount_target_id>": response.dispatch,
+    "/2015-02-01/mount-targets/<mount_target_id>/security-groups": response.dispatch,
+    "/2015-02-01/resource-tags/<resource_id>": response.dispatch,
 }
diff --git a/tests/terraform-tests.success.txt b/tests/terraform-tests.success.txt
index 1cfd9317e..ecacbc3b4 100644
--- a/tests/terraform-tests.success.txt
+++ b/tests/terraform-tests.success.txt
@@ -69,6 +69,8 @@ TestAccAWSEcrReplicationConfiguration
 TestAccAWSEcrRepository
 TestAccAWSEcrRepositoryDataSource
 TestAccAWSEcrRepositoryPolicy
+TestAccAWSEFSAccessPoint
+TestAccAWSEFSMountTarget
 TestAccAWSEgressOnlyInternetGateway
 TestAccAWSElasticBeanstalkSolutionStackDataSource
 TestAccAWSElbHostedZoneId
@@ -127,5 +129,9 @@ TestAccAWSVpc_
 TestAccAWSVpcEndpointService
 TestAccAWSVpnGateway
 TestAccAWSVpnGatewayAttachment
+TestAccDataSourceAWSEFSAccessPoint
+TestAccDataSourceAWSEFSAccessPoints
+TestAccDataSourceAwsEfsFileSystem
+TestAccDataSourceAwsEfsMountTarget
 TestAccDataSourceAwsNetworkInterface_
 TestValidateSSMDocumentPermissions
diff --git a/tests/test_efs/test_access_point_tagging.py b/tests/test_efs/test_access_point_tagging.py
new file mode 100644
index 000000000..ab70296e9
--- /dev/null
+++ b/tests/test_efs/test_access_point_tagging.py
@@ -0,0 +1,94 @@
+from os import environ
+
+import boto3
+import pytest
+
+from moto import mock_efs
+
+
+@pytest.fixture(scope="function")
+def aws_credentials():
+    """Mocked AWS Credentials for moto."""
+    environ["AWS_ACCESS_KEY_ID"] = "testing"
+    environ["AWS_SECRET_ACCESS_KEY"] = "testing"
+    environ["AWS_SECURITY_TOKEN"] = "testing"
+    environ["AWS_SESSION_TOKEN"] = "testing"
+
+
+@pytest.fixture(scope="function")
+def efs(aws_credentials):  # pylint: disable=unused-argument
+    with mock_efs():
+        yield boto3.client("efs", region_name="us-east-1")
+
+
+@pytest.fixture(scope="function")
+def file_system(efs):
+    create_fs_resp = efs.create_file_system(CreationToken="foobarbaz")
+    create_fs_resp.pop("ResponseMetadata")
+    yield create_fs_resp
+
+
+def test_list_tags_for_resource__without_tags(efs, file_system):
+    file_system_id = file_system["FileSystemId"]
+
+    ap_id = efs.create_access_point(ClientToken="ct", FileSystemId=file_system_id)[
+        "AccessPointId"
+    ]
+
+    resp = efs.list_tags_for_resource(ResourceId=ap_id)
+    resp.should.have.key("Tags").equals([])
+
+
+def test_list_tags_for_resource__with_tags(efs, file_system):
+    file_system_id = file_system["FileSystemId"]
+
+    ap_id = efs.create_access_point(
+        ClientToken="ct",
+        Tags=[{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}],
+        FileSystemId=file_system_id,
+    )["AccessPointId"]
+
+    resp = efs.list_tags_for_resource(ResourceId=ap_id)
+    resp.should.have.key("Tags").equals(
+        [{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}]
+    )
+
+
+def test_tag_resource(efs, file_system):
+    file_system_id = file_system["FileSystemId"]
+
+    ap_id = efs.create_access_point(ClientToken="ct", FileSystemId=file_system_id)[
+        "AccessPointId"
+    ]
+
+    efs.tag_resource(
+        ResourceId=ap_id,
+        Tags=[{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}],
+    )
+
+    resp = efs.list_tags_for_resource(ResourceId=ap_id)
+    resp.should.have.key("Tags").equals(
+        [{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}]
+    )
+
+
+def test_untag_resource(efs, file_system):
+    file_system_id = file_system["FileSystemId"]
+
+    ap_id = efs.create_access_point(
+        ClientToken="ct",
+        Tags=[{"Key": "key1", "Value": "val1"}],
+        FileSystemId=file_system_id,
+    )["AccessPointId"]
+
+    efs.tag_resource(
+        ResourceId=ap_id,
+        Tags=[{"Key": "key2", "Value": "val2"}, {"Key": "key3", "Value": "val3"}],
+    )
+
+    efs.untag_resource(ResourceId=ap_id, TagKeys=["key2"])
+
+    resp = efs.list_tags_for_resource(ResourceId=ap_id)
+    resp.should.have.key("Tags").equals(
+        [{"Key": "key1", "Value": "val1"}, {"Key": "key3", "Value": "val3"}]
+    )
diff --git a/tests/test_efs/test_access_points.py b/tests/test_efs/test_access_points.py
new file mode 100644
index 000000000..2523eff68
--- /dev/null
+++ b/tests/test_efs/test_access_points.py
@@ -0,0 +1,148 @@
+from os import environ
+
+import boto3
+import pytest
+from botocore.exceptions import ClientError
+
+from moto import mock_efs
+from moto.core import ACCOUNT_ID
+
+
+@pytest.fixture(scope="function")
+def aws_credentials():
+    """Mocked AWS Credentials for moto."""
+    environ["AWS_ACCESS_KEY_ID"] = "testing"
+    environ["AWS_SECRET_ACCESS_KEY"] = "testing"
+    environ["AWS_SECURITY_TOKEN"] = "testing"
+    environ["AWS_SESSION_TOKEN"] = "testing"
+
+
+@pytest.fixture(scope="function")
+def efs(aws_credentials):  # pylint: disable=unused-argument
+    with mock_efs():
+        yield boto3.client("efs", region_name="us-east-1")
+
+
+@pytest.fixture(scope="function")
+def file_system(efs):
+    create_fs_resp = efs.create_file_system(CreationToken="foobarbaz")
+    create_fs_resp.pop("ResponseMetadata")
+    yield create_fs_resp
+
+
+def test_describe_access_points__initial(efs):
+    resp = efs.describe_access_points()
+    resp.should.have.key("AccessPoints").equals([])
+
+
+def test_create_access_point__simple(efs, file_system):
+    fs_id = file_system["FileSystemId"]
+
+    resp = efs.create_access_point(ClientToken="ct", FileSystemId=fs_id)
+    resp.should.have.key("ClientToken").equals("ct")
+    resp.should.have.key("AccessPointId")
+    resp.should.have.key("AccessPointArn")
+    resp.should.have.key("FileSystemId").equals(fs_id)
+    resp.should.have.key("OwnerId").equals(ACCOUNT_ID)
+    resp.should.have.key("LifeCycleState").equals("available")
+
+    resp.should.have.key("RootDirectory").equals({"Path": "/"})
+
+
+def test_create_access_point__full(efs, file_system):
+    fs_id = file_system["FileSystemId"]
+
+    resp = efs.create_access_point(
+        ClientToken="ct",
+        Tags=[{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}],
+        FileSystemId=fs_id,
+        PosixUser={"Uid": 123, "Gid": 123, "SecondaryGids": [124, 125]},
+        RootDirectory={
+            "Path": "/root/path",
+            "CreationInfo": {
+                "OwnerUid": 987,
+                "OwnerGid": 986,
+                "Permissions": "root_permissions",
+            },
+        },
+    )
+
+    resp.should.have.key("ClientToken").equals("ct")
+    resp.should.have.key("Name").equals("myname")
+    resp.should.have.key("Tags").equals(
+        [{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}]
+    )
+    resp.should.have.key("AccessPointId")
+    resp.should.have.key("AccessPointArn")
+    resp.should.have.key("FileSystemId").equals(fs_id)
+    resp.should.have.key("PosixUser").equals(
+        {"Uid": 123, "Gid": 123, "SecondaryGids": [124, 125]}
+    )
+    resp.should.have.key("RootDirectory").equals(
+        {
+            "Path": "/root/path",
+            "CreationInfo": {
+                "OwnerUid": 987,
+                "OwnerGid": 986,
+                "Permissions": "root_permissions",
+            },
+        }
+    )
+    resp.should.have.key("OwnerId").equals(ACCOUNT_ID)
+    resp.should.have.key("LifeCycleState").equals("available")
+
+
+def test_describe_access_point(efs, file_system):
+    fs_id = file_system["FileSystemId"]
+
+    access_point_id = efs.create_access_point(ClientToken="ct", FileSystemId=fs_id)[
+        "AccessPointId"
+    ]
+
+    resp = efs.describe_access_points(AccessPointId=access_point_id)
+    resp.should.have.key("AccessPoints").length_of(1)
+    access_point = resp["AccessPoints"][0]
+
+    access_point.should.have.key("ClientToken").equals("ct")
+    access_point.should.have.key("AccessPointId")
+    access_point.should.have.key("AccessPointArn")
+    access_point.should.have.key("FileSystemId").equals(fs_id)
+    access_point.should.have.key("OwnerId").equals(ACCOUNT_ID)
+    access_point.should.have.key("LifeCycleState").equals("available")
+
+
+def test_describe_access_points__multiple(efs, file_system):
+    fs_id = file_system["FileSystemId"]
+
+    efs.create_access_point(ClientToken="ct1", FileSystemId=fs_id)
+    efs.create_access_point(ClientToken="ct2", FileSystemId=fs_id)
+
+    resp = efs.describe_access_points()
+    resp.should.have.key("AccessPoints").length_of(2)
+
+
+def test_delete_access_points(efs, file_system):
+    fs_id = file_system["FileSystemId"]
+
+    ap_id1 = efs.create_access_point(ClientToken="ct1", FileSystemId=fs_id)[
+        "AccessPointId"
+    ]
+    ap_id2 = efs.create_access_point(ClientToken="ct2", FileSystemId=fs_id)[
+        "AccessPointId"
+    ]
+
+    # Delete one access point
+    efs.delete_access_point(AccessPointId=ap_id2)
+
+    # We can only find one
+    resp = efs.describe_access_points()
+    resp.should.have.key("AccessPoints").length_of(1)
+
+    # The first one still exists
+    efs.describe_access_points(AccessPointId=ap_id1)
+
+    # The second one is gone
+    with pytest.raises(ClientError) as exc_info:
+        efs.describe_access_points(AccessPointId=ap_id2)
+    err = exc_info.value.response["Error"]
+    err["Code"].should.equal("AccessPointNotFound")
diff --git a/tests/test_efs/test_file_system.py b/tests/test_efs/test_file_system.py
index 9f78e6379..d6f04cb2f 100644
--- a/tests/test_efs/test_file_system.py
+++ b/tests/test_efs/test_file_system.py
@@ -80,7 +80,7 @@ def test_create_file_system_correct_use(efs):
         efs.describe_backup_policy(FileSystemId=create_fs_resp["FileSystemId"])
     resp = exc_info.value.response
     assert resp["ResponseMetadata"]["HTTPStatusCode"] == 404
-    assert "PolicyNotFound" in resp["Error"]["Message"]
+    assert "PolicyNotFound" == resp["Error"]["Code"]
 
     # Check the arn in detail
     match_obj = re.match(ARN_PATT, create_fs_resp["FileSystemArn"])
@@ -167,13 +167,32 @@ def test_create_file_system_file_system_already_exists(efs):
         efs.create_file_system(CreationToken="foo")
     resp = exc_info.value.response
     assert resp["ResponseMetadata"]["HTTPStatusCode"] == 409
-    assert "FileSystemAlreadyExists" in resp["Error"]["Message"]
+    assert "FileSystemAlreadyExists" == resp["Error"]["Code"]
 
 
 # Testing Describe
 # ================
 
 
+def test_describe_file_systems_using_identifier(efs):
+    # Create the file system.
+    create_fs_resp = efs.create_file_system(CreationToken="foobar")
+    create_fs_resp.pop("ResponseMetadata")
+    fs_id = create_fs_resp["FileSystemId"]
+
+    # Describe the file system.
+    desc_fs_resp = efs.describe_file_systems(FileSystemId=fs_id)
+    desc_fs_resp.should.have.key("FileSystems").length_of(1)
+    desc_fs_resp["FileSystems"][0].should.have.key("FileSystemId").equals(fs_id)
+
+
+def test_describe_file_systems_using_unknown_identifier(efs):
+    with pytest.raises(ClientError) as exc:
+        efs.describe_file_systems(FileSystemId="unknown")
+    err = exc.value.response["Error"]
+    err["Code"].should.equal("FileSystemNotFound")
+
+
 def test_describe_file_systems_minimal_case(efs):
     # Create the file system.
     create_fs_resp = efs.create_file_system(CreationToken="foobar")
@@ -306,7 +325,7 @@ def test_describe_file_systems_invalid_marker(efs):
         efs.describe_file_systems(Marker="fiddlesticks")
     resp = exc_info.value.response
     assert has_status_code(resp, 400)
-    assert "BadRequest" in resp["Error"]["Message"]
+    assert "BadRequest" == resp["Error"]["Code"]
 
 
 def test_describe_file_systems_invalid_creation_token(efs):
@@ -320,7 +339,7 @@ def test_describe_file_systems_invalid_file_system_id(efs):
         efs.describe_file_systems(FileSystemId="fs-29879313")
     resp = exc_info.value.response
     assert has_status_code(resp, 404)
-    assert "FileSystemNotFound" in resp["Error"]["Message"]
+    assert "FileSystemNotFound" == resp["Error"]["Code"]
 
 
 def test_describe_file_system_creation_token_and_file_system_id(efs):
@@ -328,7 +347,7 @@ def test_describe_file_system_creation_token_and_file_system_id(efs):
         efs.describe_file_systems(CreationToken="fizzle", FileSystemId="fs-07987987")
     resp = exc_info.value.response
     assert has_status_code(resp, 400)
-    assert "BadRequest" in resp["Error"]["Message"]
+    assert "BadRequest" == resp["Error"]["Code"]
 
 
 # Testing Delete
@@ -358,4 +377,4 @@ def test_delete_file_system_invalid_file_system_id(efs):
         efs.delete_file_system(FileSystemId="fs-2394287")
     resp = exc_info.value.response
     assert has_status_code(resp, 404)
-    assert "FileSystemNotFound" in resp["Error"]["Message"]
+    assert "FileSystemNotFound" == resp["Error"]["Code"]
diff --git a/tests/test_efs/test_filesystem_tagging.py b/tests/test_efs/test_filesystem_tagging.py
new file mode 100644
index 000000000..a0d7dae9b
--- /dev/null
+++ b/tests/test_efs/test_filesystem_tagging.py
@@ -0,0 +1,79 @@
+from os import environ
+
+import boto3
+import pytest
+
+from moto import mock_efs
+
+
+@pytest.fixture(scope="function")
+def aws_credentials():
+    """Mocked AWS Credentials for moto."""
+    environ["AWS_ACCESS_KEY_ID"] = "testing"
+    environ["AWS_SECRET_ACCESS_KEY"] = "testing"
+    environ["AWS_SECURITY_TOKEN"] = "testing"
+    environ["AWS_SESSION_TOKEN"] = "testing"
+
+
+@pytest.fixture(scope="function")
+def efs(aws_credentials):  # pylint: disable=unused-argument
+    with mock_efs():
+        yield boto3.client("efs", region_name="us-east-1")
+
+
+def test_list_tags_for_resource__without_tags(efs):
+    file_system = efs.create_file_system(CreationToken="foobarbaz")
+    fs_id = file_system["FileSystemId"]
+
+    resp = efs.list_tags_for_resource(ResourceId=fs_id)
+    resp.should.have.key("Tags").equals([])
+
+
+def test_list_tags_for_resource__with_tags(efs):
+    file_system = efs.create_file_system(
+        CreationToken="foobarbaz",
+        Tags=[{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}],
+    )
+    fs_id = file_system["FileSystemId"]
+
+    resp = efs.list_tags_for_resource(ResourceId=fs_id)
+    resp.should.have.key("Tags").equals(
+        [{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}]
+    )
+
+
+def test_tag_resource(efs):
+    file_system = efs.create_file_system(
+        CreationToken="foobarbaz",
+        Tags=[{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}],
+    )
+    fs_id = file_system["FileSystemId"]
+
+    efs.tag_resource(
+        ResourceId=fs_id,
+        Tags=[{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}],
+    )
+
+    resp = efs.list_tags_for_resource(ResourceId=fs_id)
+    resp.should.have.key("Tags").equals(
+        [{"Key": "key", "Value": "value"}, {"Key": "Name", "Value": "myname"}]
+    )
+
+
+def test_untag_resource(efs):
+    file_system = efs.create_file_system(
+        CreationToken="foobarbaz", Tags=[{"Key": "key1", "Value": "val1"}]
+    )
+    fs_id = file_system["FileSystemId"]
+
+    efs.tag_resource(
+        ResourceId=fs_id,
+        Tags=[{"Key": "key2", "Value": "val2"}, {"Key": "key3", "Value": "val3"}],
+    )
+
+    efs.untag_resource(ResourceId=fs_id, TagKeys=["key2"])
+
+    resp = efs.list_tags_for_resource(ResourceId=fs_id)
+    resp.should.have.key("Tags").equals(
+        [{"Key": "key1", "Value": "val1"}, {"Key": "key3", "Value": "val3"}]
+    )
diff --git a/tests/test_efs/test_lifecycle_config.py b/tests/test_efs/test_lifecycle_config.py
new file mode 100644
index 000000000..fbabe2162
--- /dev/null
+++ b/tests/test_efs/test_lifecycle_config.py
@@ -0,0 +1,57 @@
+from os import environ
+
+import boto3
+import pytest
+from botocore.exceptions import ClientError
+
+from moto import mock_efs
+
+
+@pytest.fixture(scope="function")
+def aws_credentials():
+    """Mocked AWS Credentials for moto."""
+    environ["AWS_ACCESS_KEY_ID"] = "testing"
+    environ["AWS_SECRET_ACCESS_KEY"] = "testing"
+    environ["AWS_SECURITY_TOKEN"] = "testing"
+    environ["AWS_SESSION_TOKEN"] = "testing"
+
+
+@pytest.fixture(scope="function")
+def efs(aws_credentials):  # pylint: disable=unused-argument
+    with mock_efs():
+        yield boto3.client("efs", region_name="us-east-1")
+
+
+def test_describe_filesystem_config__unknown(efs):
+    with pytest.raises(ClientError) as exc_info:
+        efs.describe_lifecycle_configuration(FileSystemId="unknown")
+    err = exc_info.value.response["Error"]
+    err["Code"].should.equal("FileSystemNotFound")
+    err["Message"].should.equal("File system unknown does not exist.")
+
+
+def test_describe_filesystem_config__initial(efs):
+    create_fs_resp = efs.create_file_system(CreationToken="foobar")
+    fs_id = create_fs_resp["FileSystemId"]
+
+    resp = efs.describe_lifecycle_configuration(FileSystemId=fs_id)
+    resp.should.have.key("LifecyclePolicies").equals([])
+
+
+def test_put_lifecycle_configuration(efs):
+    # Create the file system.
+    create_fs_resp = efs.create_file_system(CreationToken="foobar")
+    create_fs_resp.pop("ResponseMetadata")
+    fs_id = create_fs_resp["FileSystemId"]
+
+    # Create the lifecycle configuration
+    resp = efs.put_lifecycle_configuration(
+        FileSystemId=fs_id, LifecyclePolicies=[{"TransitionToIA": "AFTER_30_DAYS"}]
+    )
+    resp.should.have.key("LifecyclePolicies").length_of(1)
+    resp["LifecyclePolicies"][0].should.equal({"TransitionToIA": "AFTER_30_DAYS"})
+
+    # Describe the lifecycle configuration
+    resp = efs.describe_lifecycle_configuration(FileSystemId=fs_id)
+    resp.should.have.key("LifecyclePolicies").length_of(1)
+    resp["LifecyclePolicies"][0].should.equal({"TransitionToIA": "AFTER_30_DAYS"})
diff --git a/tests/test_efs/test_mount_target.py b/tests/test_efs/test_mount_target.py
index 7d07d86bb..6e2e31632 100644
--- a/tests/test_efs/test_mount_target.py
+++ b/tests/test_efs/test_mount_target.py
@@ -143,7 +143,7 @@ def test_create_mount_target_invalid_file_system_id(efs, subnet):
         efs.create_mount_target(FileSystemId="fs-12343289", SubnetId=subnet["SubnetId"])
     resp = exc_info.value.response
     assert has_status_code(resp, 404)
-    assert "FileSystemNotFound" in resp["Error"]["Message"]
+    assert "FileSystemNotFound" == resp["Error"]["Code"]
 
 
 def test_create_mount_target_invalid_subnet_id(efs, file_system):
@@ -153,7 +153,7 @@ def test_create_mount_target_invalid_subnet_id(efs, file_system):
         )
     resp = exc_info.value.response
     assert has_status_code(resp, 404)
-    assert "SubnetNotFound" in resp["Error"]["Message"]
+    assert "SubnetNotFound" == resp["Error"]["Code"]
 
 
 def test_create_mount_target_invalid_sg_id(efs, file_system, subnet):
@@ -165,7 +165,7 @@ def test_create_mount_target_invalid_sg_id(efs, file_system, subnet):
         )
     resp = exc_info.value.response
     assert has_status_code(resp, 404)
-    assert "SecurityGroupNotFound" in resp["Error"]["Message"]
+    assert "SecurityGroupNotFound" == resp["Error"]["Code"]
 
 
 def test_create_second_mount_target_wrong_vpc(efs, ec2, file_system, subnet):
@@ -183,7 +183,7 @@ def test_create_second_mount_target_wrong_vpc(efs, ec2, file_system, subnet):
         )
     resp = exc_info.value.response
     assert has_status_code(resp, 409)
-    assert "MountTargetConflict" in resp["Error"]["Message"]
+    assert "MountTargetConflict" == resp["Error"]["Code"]
     assert "VPC" in resp["Error"]["Message"]
 
 
@@ -197,7 +197,7 @@ def test_create_mount_target_duplicate_subnet_id(efs, file_system, subnet):
         )
     resp = exc_info.value.response
     assert has_status_code(resp, 409)
-    assert "MountTargetConflict" in resp["Error"]["Message"]
+    assert "MountTargetConflict" == resp["Error"]["Code"]
     assert "AZ" in resp["Error"]["Message"]
 
 
@@ -217,7 +217,7 @@ def test_create_mount_target_subnets_in_same_zone(efs, ec2, file_system, subnet)
         )
     resp = exc_info.value.response
     assert has_status_code(resp, 409)
-    assert "MountTargetConflict" in resp["Error"]["Message"]
+    assert "MountTargetConflict" == resp["Error"]["Code"]
     assert "AZ" in resp["Error"]["Message"]
 
 
@@ -230,7 +230,7 @@ def test_create_mount_target_ip_address_out_of_range(efs, file_system, subnet):
         )
     resp = exc_info.value.response
     assert has_status_code(resp, 400)
-    assert "BadRequest" in resp["Error"]["Message"]
+    assert "BadRequest" == resp["Error"]["Code"]
     assert "Address" in resp["Error"]["Message"]
 
 
@@ -251,7 +251,7 @@ def test_create_mount_target_too_many_security_groups(efs, ec2, file_system, sub
         )
     resp = exc_info.value.response
     assert has_status_code(resp, 400)
-    assert "SecurityGroupLimitExceeded" in resp["Error"]["Message"]
+    assert "SecurityGroupLimitExceeded" == resp["Error"]["Code"]
 
 
 def test_delete_file_system_mount_targets_attached(
@@ -264,7 +264,7 @@ def test_delete_file_system_mount_targets_attached(
         efs.delete_file_system(FileSystemId=file_system["FileSystemId"])
     resp = exc_info.value.response
     assert has_status_code(resp, 409)
-    assert "FileSystemInUse" in resp["Error"]["Message"]
+    assert "FileSystemInUse" == resp["Error"]["Code"]
 
 
 def test_describe_mount_targets_minimal_case(
@@ -290,6 +290,29 @@ def test_describe_mount_targets_minimal_case(
     assert mount_target == create_resp
 
 
+def test_describe_mount_targets__by_access_point_id(
+    efs, ec2, file_system, subnet
+):  # pylint: disable=unused-argument
+    create_resp = efs.create_mount_target(
+        FileSystemId=file_system["FileSystemId"], SubnetId=subnet["SubnetId"]
+    )
+    create_resp.pop("ResponseMetadata")
+
+    ap_resp = efs.create_access_point(
+        ClientToken="ct1", FileSystemId=file_system["FileSystemId"]
+    )
+    access_point_id = ap_resp["AccessPointId"]
+
+    # Describe the mount targets
+    ap_resp = efs.describe_mount_targets(AccessPointId=access_point_id)
+
+    # Check the list results.
+    ap_resp.should.have.key("MountTargets").length_of(1)
+    ap_resp["MountTargets"][0]["MountTargetId"].should.equal(
+        create_resp["MountTargetId"]
+    )
+
+
 def test_describe_mount_targets_paging(efs, ec2, file_system):
     fs_id = file_system["FileSystemId"]
 
@@ -358,7 +381,7 @@ def test_describe_mount_targets_invalid_file_system_id(efs):
         efs.describe_mount_targets(FileSystemId="fs-12343289")
     resp = exc_info.value.response
     assert has_status_code(resp, 404)
-    assert "FileSystemNotFound" in resp["Error"]["Message"]
+    assert "FileSystemNotFound" == resp["Error"]["Code"]
 
 
 def test_describe_mount_targets_invalid_mount_target_id(efs):
@@ -366,7 +389,7 @@ def test_describe_mount_targets_invalid_mount_target_id(efs):
         efs.describe_mount_targets(MountTargetId="fsmt-ad9f8987")
     resp = exc_info.value.response
     assert has_status_code(resp, 404)
-    assert "MountTargetNotFound" in resp["Error"]["Message"]
+    assert "MountTargetNotFound" == resp["Error"]["Code"]
 
 
 def test_describe_mount_targets_no_id_given(efs):
@@ -374,7 +397,7 @@ def test_describe_mount_targets_no_id_given(efs):
         efs.describe_mount_targets()
     resp = exc_info.value.response
     assert has_status_code(resp, 400)
-    assert "BadRequest" in resp["Error"]["Message"]
+    assert "BadRequest" == resp["Error"]["Code"]
 
 
 def test_delete_mount_target_minimal_case(efs, file_system, subnet):
@@ -392,4 +415,4 @@ def test_delete_mount_target_invalid_mount_target_id(efs):
         efs.delete_mount_target(MountTargetId="fsmt-98487aef0a7")
     resp = exc_info.value.response
     assert has_status_code(resp, 404)
-    assert "MountTargetNotFound" in resp["Error"]["Message"]
+    assert "MountTargetNotFound" == resp["Error"]["Code"]
diff --git a/tests/test_efs/test_mount_target_security_groups.py b/tests/test_efs/test_mount_target_security_groups.py
new file mode 100644
index 000000000..7f6fb1798
--- /dev/null
+++ b/tests/test_efs/test_mount_target_security_groups.py
@@ -0,0 +1,125 @@
+from os import environ
+
+import boto3
+import pytest
+from botocore.exceptions import ClientError
+
+from moto import mock_ec2, mock_efs
+
+
+@pytest.fixture(scope="function")
+def aws_credentials():
+    """Mocked AWS Credentials for moto."""
+    environ["AWS_ACCESS_KEY_ID"] = "testing"
+    environ["AWS_SECRET_ACCESS_KEY"] = "testing"
+    environ["AWS_SECURITY_TOKEN"] = "testing"
+    environ["AWS_SESSION_TOKEN"] = "testing"
+
+
+@pytest.fixture(scope="function")
+def ec2(aws_credentials):  # pylint: disable=unused-argument
+    with mock_ec2():
+        yield boto3.client("ec2", region_name="us-east-1")
+
+
+@pytest.fixture(scope="function")
+def efs(aws_credentials):  # pylint: disable=unused-argument
+    with mock_efs():
+        yield boto3.client("efs", region_name="us-east-1")
+
+
+@pytest.fixture(scope="function")
+def file_system(efs):
+    create_fs_resp = efs.create_file_system(CreationToken="foobarbaz")
+    create_fs_resp.pop("ResponseMetadata")
+    yield create_fs_resp
+
+
+@pytest.fixture(scope="function")
+def subnet(ec2):
+    desc_sn_resp = ec2.describe_subnets()
+    subnet = desc_sn_resp["Subnets"][0]
+    yield subnet
+
+
+def test_describe_mount_target_security_groups__unknown(efs):
+    with pytest.raises(ClientError) as exc_info:
+        efs.describe_mount_target_security_groups(MountTargetId="mt-asdf1234asdf")
+    err = exc_info.value.response["Error"]
+    err["Code"].should.equal("MountTargetNotFound")
+    err["Message"].should.equal("Mount target 'mt-asdf1234asdf' does not exist.")
+
+
+def test_describe_mount_target_security_groups(efs, ec2, file_system, subnet):
+    subnet_id = subnet["SubnetId"]
+    file_system_id = file_system["FileSystemId"]
+
+    desc_sg_resp = ec2.describe_security_groups()
+    security_group_id = desc_sg_resp["SecurityGroups"][0]["GroupId"]
+
+    # Create Mount Target
+    sample_input = {
+        "FileSystemId": file_system_id,
+        "SubnetId": subnet_id,
+        "SecurityGroups": [security_group_id],
+    }
+    create_mt_resp = efs.create_mount_target(**sample_input)
+    mount_target_id = create_mt_resp["MountTargetId"]
+
+    # Describe it's Security Groups
+    resp = efs.describe_mount_target_security_groups(MountTargetId=mount_target_id)
+    resp.should.have.key("SecurityGroups").equals([security_group_id])
+
+
+def test_modify_mount_target_security_groups__unknown(efs):
+    with pytest.raises(ClientError) as exc_info:
+        efs.modify_mount_target_security_groups(
+            MountTargetId="mt-asdf1234asdf", SecurityGroups=[]
+        )
+    err = exc_info.value.response["Error"]
+    err["Code"].should.equal("MountTargetNotFound")
+    err["Message"].should.equal("Mount target 'mt-asdf1234asdf' does not exist.")
+
+
+def test_modify_mount_target_security_groups(efs, ec2, file_system, subnet):
+    subnet_id = subnet["SubnetId"]
+    file_system_id = file_system["FileSystemId"]
+
+    desc_sg_resp = ec2.describe_security_groups()["SecurityGroups"]
+    print(desc_sg_resp)
+    security_group_id = desc_sg_resp[0]["GroupId"]
+
+    # Create Mount Target
+    sample_input = {
+        "FileSystemId": file_system_id,
+        "SubnetId": subnet_id,
+        "SecurityGroups": [security_group_id],
+    }
+    create_mt_resp = efs.create_mount_target(**sample_input)
+    mount_target_id = create_mt_resp["MountTargetId"]
+    network_interface_id = create_mt_resp["NetworkInterfaceId"]
+
+    # Create alternative security groups
+    sg_id_2 = ec2.create_security_group(
+        VpcId=subnet["VpcId"], GroupName="sg-2", Description="SG-2"
+    )["GroupId"]
+    sg_id_3 = ec2.create_security_group(
+        VpcId=subnet["VpcId"], GroupName="sg-3", Description="SG-3"
+    )["GroupId"]
+
+    # Modify it's Security Groups
+    efs.modify_mount_target_security_groups(
+        MountTargetId=mount_target_id, SecurityGroups=[sg_id_2, sg_id_3]
+    )
+
+    # Describe it's Security Groups
+    resp = efs.describe_mount_target_security_groups(MountTargetId=mount_target_id)
+    resp.should.have.key("SecurityGroups").equals([sg_id_2, sg_id_3])
+
+    # Verify EC2 reflects this change
+    resp = ec2.describe_network_interfaces(NetworkInterfaceIds=[network_interface_id])
+    network_interface = resp["NetworkInterfaces"][0]
+    network_interface["Groups"].should.have.length_of(2)
+    set([sg["GroupId"] for sg in network_interface["Groups"]]).should.equal(
+        {sg_id_2, sg_id_3}
+    )