diff --git a/moto/iam/models.py b/moto/iam/models.py
index c150d1c99..c219c1afc 100644
--- a/moto/iam/models.py
+++ b/moto/iam/models.py
@@ -11,6 +11,19 @@ from .utils import random_access_key, random_alphanumeric, random_resource_id, r
 ACCOUNT_ID = 123456789012
 
 
+class MFADevice(object):
+    """MFA Device class."""
+
+    def __init__(self,
+                 serial_number,
+                 authentication_code_1,
+                 authentication_code_2):
+        self.enable_date = datetime.now(pytz.utc)
+        self.serial_number = serial_number
+        self.authentication_code_1 = authentication_code_1
+        self.authentication_code_2 = authentication_code_2
+
+
 class Policy(BaseModel):
 
     is_attachable = False
@@ -226,6 +239,7 @@ class User(BaseModel):
             datetime.utcnow(),
             "%Y-%m-%d-%H-%M-%S"
         )
+        self.mfa_devices = {}
         self.policies = {}
         self.access_keys = []
         self.password = None
@@ -251,6 +265,9 @@ class User(BaseModel):
     def put_policy(self, policy_name, policy_json):
         self.policies[policy_name] = policy_json
 
+    def deactivate_mfa_device(self, serial_number):
+        self.mfa_devices.pop(serial_number)
+
     def delete_policy(self, policy_name):
         if policy_name not in self.policies:
             raise IAMNotFoundException(
@@ -263,6 +280,16 @@ class User(BaseModel):
         self.access_keys.append(access_key)
         return access_key
 
+    def enable_mfa_device(self,
+                          serial_number,
+                          authentication_code_1,
+                          authentication_code_2):
+        self.mfa_devices[serial_number] = MFADevice(
+            serial_number,
+            authentication_code_1,
+            authentication_code_2
+        )
+
     def get_all_access_keys(self):
         return self.access_keys
 
@@ -724,6 +751,39 @@ class IAMBackend(BaseBackend):
         user = self.get_user(user_name)
         user.delete_access_key(access_key_id)
 
+    def enable_mfa_device(self,
+                          user_name,
+                          serial_number,
+                          authentication_code_1,
+                          authentication_code_2):
+        """Enable MFA Device for user."""
+        user = self.get_user(user_name)
+        if serial_number in user.mfa_devices:
+            raise IAMConflictException(
+                "EntityAlreadyExists",
+                "Device {0} already exists".format(serial_number)
+            )
+
+        user.enable_mfa_device(
+            serial_number,
+            authentication_code_1,
+            authentication_code_2
+        )
+
+    def deactivate_mfa_device(self, user_name, serial_number):
+        """Deactivate and detach MFA Device from user if device exists."""
+        user = self.get_user(user_name)
+        if serial_number not in user.mfa_devices:
+            raise IAMNotFoundException(
+                "Device {0} not found".format(serial_number)
+            )
+
+        user.deactivate_mfa_device(serial_number)
+
+    def list_mfa_devices(self, user_name):
+        user = self.get_user(user_name)
+        return user.mfa_devices.values()
+
     def delete_user(self, user_name):
         try:
             del self.users[user_name]
diff --git a/moto/iam/responses.py b/moto/iam/responses.py
index 27e69537d..0757d7eee 100644
--- a/moto/iam/responses.py
+++ b/moto/iam/responses.py
@@ -326,6 +326,35 @@ class IamResponse(BaseResponse):
         template = self.response_template(GENERIC_EMPTY_TEMPLATE)
         return template.render(name='DeleteAccessKey')
 
+    def deactivate_mfa_device(self):
+        user_name = self._get_param('UserName')
+        serial_number = self._get_param('SerialNumber')
+
+        iam_backend.deactivate_mfa_device(user_name, serial_number)
+        template = self.response_template(GENERIC_EMPTY_TEMPLATE)
+        return template.render(name='DeactivateMFADevice')
+
+    def enable_mfa_device(self):
+        user_name = self._get_param('UserName')
+        serial_number = self._get_param('SerialNumber')
+        authentication_code_1 = self._get_param('AuthenticationCode1')
+        authentication_code_2 = self._get_param('AuthenticationCode2')
+
+        iam_backend.enable_mfa_device(
+            user_name,
+            serial_number,
+            authentication_code_1,
+            authentication_code_2
+        )
+        template = self.response_template(GENERIC_EMPTY_TEMPLATE)
+        return template.render(name='EnableMFADevice')
+
+    def list_mfa_devices(self):
+        user_name = self._get_param('UserName')
+        devices = iam_backend.list_mfa_devices(user_name)
+        template = self.response_template(LIST_MFA_DEVICES_TEMPLATE)
+        return template.render(user_name=user_name, devices=devices)
+
     def delete_user(self):
         user_name = self._get_param('UserName')
         iam_backend.delete_user(user_name)
@@ -922,3 +951,20 @@ LIST_INSTANCE_PROFILES_FOR_ROLE_TEMPLATE = """<ListInstanceProfilesForRoleRespon
   <RequestId>6a8c3992-99f4-11e1-a4c3-27EXAMPLE804</RequestId>
 </ResponseMetadata>
 </ListInstanceProfilesForRoleResponse>"""
+
+LIST_MFA_DEVICES_TEMPLATE = """<ListMFADevicesResponse>
+   <ListMFADevicesResult>
+      <MFADevices>
+        {% for device in devices %}
+         <member>
+            <UserName>{{ user_name }}</UserName>
+            <SerialNumber>{{ device.serial_number }}</SerialNumber>
+         </member>
+        {% endfor %}
+      </MFADevices>
+      <IsTruncated>false</IsTruncated>
+   </ListMFADevicesResult>
+   <ResponseMetadata>
+      <RequestId>7a62c49f-347e-4fc4-9331-6e8eEXAMPLE</RequestId>
+   </ResponseMetadata>
+</ListMFADevicesResponse>"""
diff --git a/tests/test_iam/test_iam.py b/tests/test_iam/test_iam.py
index 021d7c041..1ae892f62 100644
--- a/tests/test_iam/test_iam.py
+++ b/tests/test_iam/test_iam.py
@@ -292,6 +292,29 @@ def test_delete_access_key():
     conn.delete_access_key(access_key_id, 'my-user')
 
 
+@mock_iam()
+def test_mfa_devices():
+    # Test enable device
+    conn = boto3.client('iam', region_name='us-east-1')
+    conn.create_user(UserName='my-user')
+    conn.enable_mfa_device(
+        UserName='my-user',
+        SerialNumber='123456789',
+        AuthenticationCode1='234567',
+        AuthenticationCode2='987654'
+    )
+
+    # Test list mfa devices
+    response = conn.list_mfa_devices(UserName='my-user')
+    device = response['MFADevices'][0]
+    device['SerialNumber'].should.equal('123456789')
+
+    # Test deactivate mfa device
+    conn.deactivate_mfa_device(UserName='my-user', SerialNumber='123456789')
+    response = conn.list_mfa_devices(UserName='my-user')
+    len(response['MFADevices']).should.equal(0)
+
+
 @mock_iam_deprecated()
 def test_delete_user():
     conn = boto.connect_iam()