diff --git a/moto/iam/models.py b/moto/iam/models.py
index 49f917c53..76c1842a7 100644
--- a/moto/iam/models.py
+++ b/moto/iam/models.py
@@ -1,4 +1,5 @@
 import base64
+import copy
 import os
 import string
 from datetime import datetime
@@ -438,6 +439,12 @@ class ManagedPolicy(Policy, CloudFormationModel):
             )
         return policy
 
+    def __eq__(self, other: Any) -> bool:
+        return self.arn == other.arn
+
+    def __hash__(self) -> int:
+        return self.arn.__hash__()
+
     @property
     def physical_resource_id(self) -> str:
         return self.arn
@@ -1791,8 +1798,8 @@ class IAMBackend(BaseBackend):
         self.initialize_service_roles()
 
     def _init_aws_policies(self) -> List[ManagedPolicy]:
-        # AWS defines some of its own managed policies and we periodically
-        # import them via `make aws_managed_policies`
+        # AWS defines some of its own managed policies
+        # we periodically import them via `make aws_managed_policies`
         aws_managed_policies_data_parsed = json.loads(aws_managed_policies_data)
         return [
             AWSManagedPolicy.from_data(name, self.account_id, d)
@@ -1800,7 +1807,7 @@ class IAMBackend(BaseBackend):
         ]
 
     def _init_managed_policies(self) -> Dict[str, ManagedPolicy]:
-        return dict((p.arn, p) for p in self.aws_managed_policies)
+        return dict((p.arn, copy.deepcopy(p)) for p in self.aws_managed_policies)
 
     def reset(self) -> None:
         region_name = self.region_name
diff --git a/tests/test_iam/test_iam.py b/tests/test_iam/test_iam.py
index aeb9a5505..fc733d29f 100644
--- a/tests/test_iam/test_iam.py
+++ b/tests/test_iam/test_iam.py
@@ -3368,7 +3368,7 @@ def test_get_account_summary():
         "ServerCertificatesQuota": 20,
         "MFADevices": 0,
         "UserPolicySizeQuota": 2048,
-        "PolicyVersionsInUse": 1,
+        "PolicyVersionsInUse": 0,
         "ServerCertificates": 0,
         "Roles": 0,
         "RolesQuota": 1000,
@@ -3438,7 +3438,7 @@ def test_get_account_summary():
         "ServerCertificatesQuota": 20,
         "MFADevices": 1,
         "UserPolicySizeQuota": 2048,
-        "PolicyVersionsInUse": 4,
+        "PolicyVersionsInUse": 3,
         "ServerCertificates": 1,
         "Roles": 1,
         "RolesQuota": 1000,
diff --git a/tests/test_iam/test_iam_resets.py b/tests/test_iam/test_iam_resets.py
new file mode 100644
index 000000000..0422a0ec7
--- /dev/null
+++ b/tests/test_iam/test_iam_resets.py
@@ -0,0 +1,38 @@
+import boto3
+import json
+
+from moto import mock_iam
+
+
+# Test IAM User Inline Policy
+def test_policies_are_not_kept_after_mock_ends():
+    iam_client = boto3.client("iam", "us-east-1")
+    with mock_iam():
+        role_name = "test"
+        assume_role_policy_document = {
+            "Version": "2012-10-17",
+            "Statement": {
+                "Effect": "Allow",
+                "Principal": {"AWS": "*"},
+                "Action": "sts:AssumeRole",
+            },
+        }
+        iam_client.create_role(
+            RoleName=role_name,
+            AssumeRolePolicyDocument=json.dumps(assume_role_policy_document),
+        )
+        iam_client.attach_role_policy(
+            RoleName=role_name,
+            PolicyArn="arn:aws:iam::aws:policy/ReadOnlyAccess",
+        )
+
+        iam_policies = iam_client.list_policies(Scope="AWS", OnlyAttached=True)[
+            "Policies"
+        ]
+        assert len(iam_policies) == 1
+        assert iam_policies[0]["Arn"] == "arn:aws:iam::aws:policy/ReadOnlyAccess"
+        assert iam_client.list_roles()["Roles"][0]["RoleName"] == "test"
+
+    with mock_iam():
+        resp = iam_client.list_policies(Scope="AWS", OnlyAttached=True)
+        assert len(resp["Policies"]) == 0