diff --git a/sqlmodel/main.py b/sqlmodel/main.py
index 2e558647f1..38b0a215b4 100644
--- a/sqlmodel/main.py
+++ b/sqlmodel/main.py
@@ -46,8 +46,9 @@
 from sqlalchemy.orm.attributes import set_attribute
 from sqlalchemy.orm.decl_api import DeclarativeMeta
 from sqlalchemy.orm.instrumentation import is_instrumented
-from sqlalchemy.sql.schema import MetaData
+from sqlalchemy.sql.schema import MetaData, SchemaEventTarget
 from sqlalchemy.sql.sqltypes import LargeBinary, Time, Uuid
+from sqlalchemy.types import TypeEngine
 from typing_extensions import Literal, TypeAlias, deprecated, get_origin
 
 from ._compat import (  # type: ignore[attr-defined]
@@ -92,6 +93,11 @@
     Mapping[int, Union["IncEx", bool]],
     Mapping[str, Union["IncEx", bool]],
 ]
+SaTypeOrInstance: TypeAlias = Union[
+    TypeEngine[Any],
+    type[TypeEngine[Any]],
+    SchemaEventTarget,
+]
 OnDeleteType = Literal["CASCADE", "SET NULL", "RESTRICT"]
 
 
@@ -240,7 +246,7 @@ def Field(
     unique: Union[bool, UndefinedType] = Undefined,
     nullable: Union[bool, UndefinedType] = Undefined,
     index: Union[bool, UndefinedType] = Undefined,
-    sa_type: Union[type[Any], UndefinedType] = Undefined,
+    sa_type: Union[SaTypeOrInstance, UndefinedType] = Undefined,
     sa_column_args: Union[Sequence[Any], UndefinedType] = Undefined,
     sa_column_kwargs: Union[Mapping[str, Any], UndefinedType] = Undefined,
     schema_extra: Optional[dict[str, Any]] = None,
@@ -284,7 +290,7 @@ def Field(
     unique: Union[bool, UndefinedType] = Undefined,
     nullable: Union[bool, UndefinedType] = Undefined,
     index: Union[bool, UndefinedType] = Undefined,
-    sa_type: Union[type[Any], UndefinedType] = Undefined,
+    sa_type: Union[SaTypeOrInstance, UndefinedType] = Undefined,
     sa_column_args: Union[Sequence[Any], UndefinedType] = Undefined,
     sa_column_kwargs: Union[Mapping[str, Any], UndefinedType] = Undefined,
     schema_extra: Optional[dict[str, Any]] = None,
@@ -369,7 +375,7 @@ def Field(
     unique: Union[bool, UndefinedType] = Undefined,
     nullable: Union[bool, UndefinedType] = Undefined,
     index: Union[bool, UndefinedType] = Undefined,
-    sa_type: Union[type[Any], UndefinedType] = Undefined,
+    sa_type: Union[SaTypeOrInstance, UndefinedType] = Undefined,
     sa_column: Union[Column, UndefinedType] = Undefined,  # type: ignore
     sa_column_args: Union[Sequence[Any], UndefinedType] = Undefined,
     sa_column_kwargs: Union[Mapping[str, Any], UndefinedType] = Undefined,