diff --git a/moto/ssm/models.py b/moto/ssm/models.py
index c8c428b64..d8dc10a4b 100644
--- a/moto/ssm/models.py
+++ b/moto/ssm/models.py
@@ -5,13 +5,17 @@ from collections import defaultdict
 from moto.core import BaseBackend, BaseModel
 from moto.ec2 import ec2_backends
 
+import time
+
 
 class Parameter(BaseModel):
-    def __init__(self, name, value, type, description, keyid):
+    def __init__(self, name, value, type, description, keyid, last_modified_date, version):
         self.name = name
         self.type = type
         self.description = description
         self.keyid = keyid
+        self.last_modified_date = last_modified_date
+        self.version = version
 
         if self.type == 'SecureString':
             self.value = self.encrypt(value)
@@ -33,8 +37,20 @@ class Parameter(BaseModel):
         r = {
             'Name': self.name,
             'Type': self.type,
-            'Value': self.decrypt(self.value) if decrypt else self.value
+            'Value': self.decrypt(self.value) if decrypt else self.value,
+            'Version': self.version,
         }
+
+        return r
+
+    def describe_response_object(self, decrypt=False):
+        r = self.response_object(decrypt)
+        r['LastModifiedDate'] = int(self.last_modified_date)
+        r['LastModifiedUser'] = 'N/A'
+
+        if self.description:
+            r['Description'] = self.description
+
         if self.keyid:
             r['KeyId'] = self.keyid
         return r
@@ -96,10 +112,18 @@ class SimpleSystemManagerBackend(BaseBackend):
         return None
 
     def put_parameter(self, name, description, value, type, keyid, overwrite):
-        if not overwrite and name in self._parameters:
-            return
+        previous_parameter = self._parameters.get(name)
+        version = 1
+
+        if previous_parameter:
+            version = previous_parameter.version + 1
+
+            if not overwrite:
+                return
+
+        last_modified_date = time.time()
         self._parameters[name] = Parameter(
-            name, value, type, description, keyid)
+            name, value, type, description, keyid, last_modified_date, version)
 
     def add_tags_to_resource(self, resource_type, resource_id, tags):
         for key, value in tags.items():
diff --git a/moto/ssm/responses.py b/moto/ssm/responses.py
index 3227839b9..0b4ca3b65 100644
--- a/moto/ssm/responses.py
+++ b/moto/ssm/responses.py
@@ -117,7 +117,7 @@ class SimpleSystemManagerResponse(BaseResponse):
 
         end = token + page_size
         for parameter in result[token:]:
-            param_data = parameter.response_object(False)
+            param_data = parameter.describe_response_object(False)
             add = False
 
             if filters:
diff --git a/tests/test_ssm/test_ssm_boto3.py b/tests/test_ssm/test_ssm_boto3.py
index 781727c26..ff8e5e8a4 100644
--- a/tests/test_ssm/test_ssm_boto3.py
+++ b/tests/test_ssm/test_ssm_boto3.py
@@ -3,6 +3,7 @@ from __future__ import unicode_literals
 import boto3
 import botocore.exceptions
 import sure   # noqa
+import datetime
 
 from moto import mock_ssm
 
@@ -112,6 +113,46 @@ def test_put_parameter():
     response['Parameters'][0]['Name'].should.equal('test')
     response['Parameters'][0]['Value'].should.equal('value')
     response['Parameters'][0]['Type'].should.equal('String')
+    response['Parameters'][0]['Version'].should.equal(1)
+
+    client.put_parameter(
+        Name='test',
+        Description='desc 2',
+        Value='value 2',
+        Type='String')
+
+    response = client.get_parameters(
+        Names=[
+            'test'
+        ],
+        WithDecryption=False)
+
+    # without overwrite nothing change
+    len(response['Parameters']).should.equal(1)
+    response['Parameters'][0]['Name'].should.equal('test')
+    response['Parameters'][0]['Value'].should.equal('value')
+    response['Parameters'][0]['Type'].should.equal('String')
+    response['Parameters'][0]['Version'].should.equal(1)
+
+    client.put_parameter(
+        Name='test',
+        Description='desc 3',
+        Value='value 3',
+        Type='String',
+        Overwrite=True)
+
+    response = client.get_parameters(
+        Names=[
+            'test'
+        ],
+        WithDecryption=False)
+
+    # without overwrite nothing change
+    len(response['Parameters']).should.equal(1)
+    response['Parameters'][0]['Name'].should.equal('test')
+    response['Parameters'][0]['Value'].should.equal('value 3')
+    response['Parameters'][0]['Type'].should.equal('String')
+    response['Parameters'][0]['Version'].should.equal(2)
 
 
 @mock_ssm
@@ -279,6 +320,33 @@ def test_describe_parameters_filter_keyid():
     response['Parameters'][0]['Type'].should.equal('SecureString')
     ''.should.equal(response.get('NextToken', ''))
 
+@mock_ssm
+def test_describe_parameters_attributes():
+    client = boto3.client('ssm', region_name='us-east-1')
+
+    client.put_parameter(
+        Name='aa',
+        Value='11',
+        Type='String',
+        Description='my description'
+    )
+
+    client.put_parameter(
+        Name='bb',
+        Value='22',
+        Type='String'
+    )
+
+    response = client.describe_parameters()
+    len(response['Parameters']).should.equal(2)
+
+    response['Parameters'][0]['Description'].should.equal('my description')
+    response['Parameters'][0]['Version'].should.equal(1)
+    response['Parameters'][0]['LastModifiedDate'].should.be.a(datetime.date)
+    response['Parameters'][0]['LastModifiedUser'].should.equal('N/A')
+
+    response['Parameters'][1].get('Description').should.be.none
+    response['Parameters'][1]['Version'].should.equal(1)
 
 @mock_ssm
 def test_get_parameter_invalid():