diff --git a/fastapi_msal/models/base_auth_model.py b/fastapi_msal/models/base_auth_model.py
index 994eca0..b9cbc2a 100644
--- a/fastapi_msal/models/base_auth_model.py
+++ b/fastapi_msal/models/base_auth_model.py
@@ -1,6 +1,6 @@
 from typing import Optional, TypeVar
 
-from pydantic import BaseModel, PrivateAttr
+from pydantic import BaseModel, ConfigDict, PrivateAttr
 
 from fastapi_msal.core import OptStrsDict, SessionManager, StrsDict
 
@@ -9,6 +9,14 @@
 
 class BaseAuthModel(BaseModel):
     _recieved: OptStrsDict = PrivateAttr(None)
+    model_config = ConfigDict(extra="allow")
+    """
+    extra="allow"
+        for Pydantic to save additional fields that are not defined in the model.
+        Since the ID token can have additional fields defined in the app registration portal.
+        To access these fields (if any), use the `__pydantic_extra__` attribute of the object.
+        https://docs.pydantic.dev/latest/concepts/models/#extra-fields
+    """
 
     @classmethod
     def parse_obj_debug(cls: type[AuthModel], to_parse: StrsDict) -> AuthModel:
diff --git a/fastapi_msal/models/id_token_claims.py b/fastapi_msal/models/id_token_claims.py
index f7252b9..7ad6cfe 100644
--- a/fastapi_msal/models/id_token_claims.py
+++ b/fastapi_msal/models/id_token_claims.py
@@ -8,6 +8,7 @@
 
 from fastapi_msal.core import MSALPolicies, OptStr, OptStrsDict
 
+from .base_auth_model import BaseAuthModel
 from .user_info import UserInfo
 
 
@@ -76,7 +77,7 @@ class AADInternalClaims(BaseModel):
     """
 
 
-class IDTokenClaims(UserInfo, AADInternalClaims):
+class IDTokenClaims(UserInfo, AADInternalClaims, BaseAuthModel):
     """
     The ID token is a security token that contains claims about the authentication of an end-user by
       an authorization server, when using a client, and potentially other requested claims.
@@ -193,6 +194,13 @@ class IDTokenClaims(UserInfo, AADInternalClaims):
     _id_token: Optional[str] = PrivateAttr(None)
     """
     The raw id_token that was used to create this object - private attribute for internal use only
+    Will be set only via the `decode_id_token` method
+    """
+
+    _decoded_token: OptStrsDict = PrivateAttr(None)
+    """
+    The decoded token that was used to create this object - private attribute for internal use only
+    Will be set only via the `decode_id_token` method
     """
 
     @staticmethod
diff --git a/fastapi_msal/models/user_info.py b/fastapi_msal/models/user_info.py
index 0817078..df455c2 100644
--- a/fastapi_msal/models/user_info.py
+++ b/fastapi_msal/models/user_info.py
@@ -1,8 +1,8 @@
-from typing import Optional
+from typing import Optional, Union
 
 from pydantic import BaseModel, Field
 
-from fastapi_msal.core import OptStr, OptStrList
+from fastapi_msal.core import OptStr, OptStrList, StrList
 
 
 class UserInfo(BaseModel):
@@ -93,3 +93,16 @@ class UserInfo(BaseModel):
     Indicates that the client should use the Microsoft Graph API to determine the user's groups
     (https://graph.microsoft.com/v1.0/users/{userID}/getMemberObjects).
     """
+
+    groups: Union[StrList, str, None] = None
+    """
+    Provides object IDs that represent the group memberships of the subject.
+    The groupMembershipClaims property of the application manifest configures the groups claim on a per-application basis.
+    A value of null excludes all groups, a value of SecurityGroup includes only Active Directory Security Groups,
+    and a value of All includes both Security Groups and Microsoft 365 Distribution Lists.
+
+    See the hasgroups claim for details on using the groups claim with the implicit grant. For other flows,
+    if the number of groups the user is in goes over 150 for SAML and 200 for JWT,
+    then Microsoft Entra ID adds an overage claim to the claim sources.
+    The claim sources point to the Microsoft Graph endpoint that contains the list of groups for the user.
+    """