diff --git a/src/ga4gh/core/models.py b/src/ga4gh/core/models.py
index c71b294b..b96fac13 100644
--- a/src/ga4gh/core/models.py
+++ b/src/ga4gh/core/models.py
@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-from abc import ABC
 from enum import Enum
 from typing import Annotated, Any, ClassVar, Literal
 
@@ -120,11 +119,8 @@ def ga4gh_serialize(self) -> str:  # noqa: D102
 #########################################
 
 
-class Element(GKMCoreMetadataMixin, BaseModel, ABC):
-    """The base definition for all identifiable data objects.
-
-    Abstract base class to be extended by other classes. Do NOT instantiate directly.
-    """
+class Element(GKMCoreMetadataMixin, BaseModel):
+    """The base definition for all identifiable data objects."""
 
     _maturity: ClassVar[Maturity] = Maturity.TRIAL_USE
     _abstract: ClassVar[bool] = True
@@ -174,11 +170,8 @@ class Extension(Element, BaseModelForbidExtra):
     )
 
 
-class Entity(GKMCoreMetadataMixin, BaseModel, ABC):
-    """Anything that exists, has existed, or will exist.
-
-    Abstract base class to be extended by other classes. Do NOT instantiate directly.
-    """
+class Entity(GKMCoreMetadataMixin, BaseModel):
+    """Anything that exists, has existed, or will exist."""
 
     _maturity: ClassVar[Maturity] = Maturity.TRIAL_USE
     _abstract: ClassVar[bool] = True
diff --git a/src/ga4gh/vrs/models.py b/src/ga4gh/vrs/models.py
index 2b1ed69b..8e990dc2 100644
--- a/src/ga4gh/vrs/models.py
+++ b/src/ga4gh/vrs/models.py
@@ -293,7 +293,7 @@ def is_ga4gh_identifiable() -> bool:
         return False
 
 
-class Ga4ghIdentifiableObject(VRSMetadataMixin, _ValueObject, ABC):
+class Ga4ghIdentifiableObject(VRSMetadataMixin, _ValueObject):
     """A contextual value object for which a GA4GH computed identifier can be created.
     All GA4GH Identifiable Objects may have computed digests from the VRS Computed
     Identifier algorithm.