diff --git a/pandas/_libs/internals.pyi b/pandas/_libs/internals.pyi
index 143f6b68deaa6..79bdbea71e4d8 100644
--- a/pandas/_libs/internals.pyi
+++ b/pandas/_libs/internals.pyi
@@ -44,7 +44,9 @@ class BlockPlacement:
     @property
     def is_slice_like(self) -> bool: ...
     @overload
-    def __getitem__(self, loc: slice | Sequence[int]) -> BlockPlacement: ...
+    def __getitem__(
+        self, loc: slice | Sequence[int] | npt.NDArray[np.intp]
+    ) -> BlockPlacement: ...
     @overload
     def __getitem__(self, loc: int) -> int: ...
     def __iter__(self) -> Iterator[int]: ...
diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 8fb6a18ca137a..b7da5d82c85f3 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -258,9 +258,7 @@ def getitem_block(self, slicer: slice | npt.NDArray[np.intp]) -> Block:
         #  is from internals.concat, and we can verify that never happens
         #  with 1-column blocks, i.e. never for ExtensionBlock.
 
-        # Invalid index type "Union[slice, ndarray[Any, dtype[signedinteger[Any]]]]"
-        # for "BlockPlacement"; expected type "Union[slice, Sequence[int]]"
-        new_mgr_locs = self._mgr_locs[slicer]  # type: ignore[index]
+        new_mgr_locs = self._mgr_locs[slicer]
 
         new_values = self._slice(slicer)
 
diff --git a/pandas/core/internals/managers.py b/pandas/core/internals/managers.py
index 71d8b20f18457..81c5810d29456 100644
--- a/pandas/core/internals/managers.py
+++ b/pandas/core/internals/managers.py
@@ -1320,11 +1320,11 @@ def _iset_split_block(
 
         nbs_tup = tuple(blk.delete(blk_locs))
         if value is not None:
-            # error: No overload variant of "__getitem__" of "BlockPlacement" matches
-            # argument type "ndarray[Any, Any]"  [call-overload]
+            # Argument 1 to "BlockPlacement" has incompatible type "BlockPlacement";
+            # expected "Union[int, slice, ndarray[Any, Any]]"
             first_nb = new_block_2d(
                 value,
-                BlockPlacement(blk.mgr_locs[blk_locs]),  # type: ignore[call-overload]
+                BlockPlacement(blk.mgr_locs[blk_locs]),  # type: ignore[arg-type]
             )
         else:
             first_nb = nbs_tup[0]