diff --git a/moto/organizations/models.py b/moto/organizations/models.py
index e25342f04..93408a353 100644
--- a/moto/organizations/models.py
+++ b/moto/organizations/models.py
@@ -95,6 +95,19 @@ class FakeAccount(BaseModel):
             }
         }
 
+    @property
+    def close_account_status(self):
+        return {
+            "CloseAccountStatus": {
+                "Id": self.create_account_status_id,
+                "AccountName": self.name,
+                "State": "SUCCEEDED",
+                "RequestedTimestamp": unix_time(datetime.datetime.utcnow()),
+                "CompletedTimestamp": unix_time(datetime.datetime.utcnow()),
+                "AccountId": self.id,
+            }
+        }
+
     def describe(self):
         return {
             "Id": self.id,
@@ -445,6 +458,17 @@ class OrganizationsBackend(BaseBackend):
         self.attach_policy(PolicyId=utils.DEFAULT_POLICY_ID, TargetId=new_account.id)
         return new_account.create_account_status
 
+    def close_account(self, **kwargs):
+        for account_index in range(len(self.accounts)):
+            if kwargs["AccountId"] == self.accounts[account_index].id:
+                closed_account_status = self.accounts[
+                    account_index
+                ].close_account_status
+                del self.accounts[account_index]
+                return closed_account_status
+
+        raise AccountNotFoundException
+
     def get_account_by_id(self, account_id):
         account = next(
             (account for account in self.accounts if account.id == account_id), None
diff --git a/moto/organizations/responses.py b/moto/organizations/responses.py
index 5d0bdc482..c731a321a 100644
--- a/moto/organizations/responses.py
+++ b/moto/organizations/responses.py
@@ -67,6 +67,11 @@ class OrganizationsResponse(BaseResponse):
             self.organizations_backend.create_account(**self.request_params)
         )
 
+    def close_account(self):
+        return json.dumps(
+            self.organizations_backend.close_account(**self.request_params)
+        )
+
     def describe_account(self):
         return json.dumps(
             self.organizations_backend.describe_account(**self.request_params)
diff --git a/tests/test_organizations/organizations_test_utils.py b/tests/test_organizations/organizations_test_utils.py
index 15bee591b..1a3caae22 100644
--- a/tests/test_organizations/organizations_test_utils.py
+++ b/tests/test_organizations/organizations_test_utils.py
@@ -135,3 +135,17 @@ def validate_service_control_policy(org, response):
     response.should.have.key("PolicySummary").should.be.a(dict)
     response.should.have.key("Content").should.be.a(str)
     validate_policy_summary(org, response["PolicySummary"])
+
+
+def validate_account_created(accounts_list, account_id):
+    account_created = False
+    for account in accounts_list:
+        if account_id == account["Id"]:
+            account_created = True
+    assert account_created
+
+
+def validate_account_closed(accounts_list, account_id):
+    for account in accounts_list:
+        if account_id == account["Id"]:
+            assert False
diff --git a/tests/test_organizations/test_organizations_boto3.py b/tests/test_organizations/test_organizations_boto3.py
index a5bd14b80..52f9c8063 100644
--- a/tests/test_organizations/test_organizations_boto3.py
+++ b/tests/test_organizations/test_organizations_boto3.py
@@ -27,6 +27,8 @@ from .organizations_test_utils import (
     validate_create_account_status,
     validate_service_control_policy,
     validate_policy_summary,
+    validate_account_created,
+    validate_account_closed,
 )
 
 
@@ -173,6 +175,46 @@ def test_create_account():
     create_status["AccountName"].should.equal(mockname)
 
 
+@mock_organizations
+def test_close_account():
+    client = boto3.client("organizations", region_name="us-east-1")
+    client.create_organization(FeatureSet="ALL")
+    create_status = client.create_account(AccountName=mockname, Email=mockemail)[
+        "CreateAccountStatus"
+    ]
+    created_account_id = create_status["AccountId"]
+    accounts_list_before = client.list_accounts()["Accounts"]
+    validate_account_created(
+        accounts_list=accounts_list_before,
+        account_id=created_account_id,
+    )
+
+    client.close_account(AccountId=created_account_id)
+
+    accounts_list_after = client.list_accounts()["Accounts"]
+    validate_account_closed(accounts_list_after, created_account_id)
+    number_accounts_before = len(accounts_list_before)
+    number_accounts_after = len(accounts_list_after)
+    (number_accounts_before - number_accounts_after).should.equal(1)
+
+
+@mock_organizations
+def test_close_account_exception():
+    client = boto3.client("organizations", region_name="us-east-1")
+    client.create_organization(FeatureSet="ALL")
+    uncreated_fake_account_id = "123456789101"
+
+    with pytest.raises(ClientError) as e:
+        client.close_account(AccountId=uncreated_fake_account_id)
+    ex = e.value
+    ex.operation_name.should.equal("CloseAccount")
+    ex.response["ResponseMetadata"]["HTTPStatusCode"].should.equal(400)
+    ex.response["Error"]["Code"].should.contain("AccountNotFoundException")
+    ex.response["Error"]["Message"].should.equal(
+        "You specified an account that doesn't exist."
+    )
+
+
 @mock_organizations
 def test_describe_create_account_status():
     client = boto3.client("organizations", region_name="us-east-1")