diff --git a/src/amrex/space1d/amrex_1d_pybind/__init__.pyi b/src/amrex/space1d/amrex_1d_pybind/__init__.pyi
index 039dbe0d..6b26cf94 100644
--- a/src/amrex/space1d/amrex_1d_pybind/__init__.pyi
+++ b/src/amrex/space1d/amrex_1d_pybind/__init__.pyi
@@ -5212,6 +5212,10 @@ class FabArrayBase:
     def __iter__(fab): ...
     @staticmethod
     def _pybind11_conduit_v1_(*args, **kwargs): ...
+    def __len__(self) -> int:
+        """
+        Return the number of FABs in the FabArray.
+        """
     def is_nodal(self, arg0: int) -> bool: ...
     @property
     def is_all_cell_centered(self) -> bool: ...
diff --git a/src/amrex/space2d/amrex_2d_pybind/__init__.pyi b/src/amrex/space2d/amrex_2d_pybind/__init__.pyi
index e8c2201c..7f4ae7be 100644
--- a/src/amrex/space2d/amrex_2d_pybind/__init__.pyi
+++ b/src/amrex/space2d/amrex_2d_pybind/__init__.pyi
@@ -5236,6 +5236,10 @@ class FabArrayBase:
     def __iter__(fab): ...
     @staticmethod
     def _pybind11_conduit_v1_(*args, **kwargs): ...
+    def __len__(self) -> int:
+        """
+        Return the number of FABs in the FabArray.
+        """
     def is_nodal(self, arg0: int) -> bool: ...
     @property
     def is_all_cell_centered(self) -> bool: ...
diff --git a/src/amrex/space3d/amrex_3d_pybind/__init__.pyi b/src/amrex/space3d/amrex_3d_pybind/__init__.pyi
index 971aa0de..23f5a6cc 100644
--- a/src/amrex/space3d/amrex_3d_pybind/__init__.pyi
+++ b/src/amrex/space3d/amrex_3d_pybind/__init__.pyi
@@ -5212,6 +5212,10 @@ class FabArrayBase:
     def __iter__(fab): ...
     @staticmethod
     def _pybind11_conduit_v1_(*args, **kwargs): ...
+    def __len__(self) -> int:
+        """
+        Return the number of FABs in the FabArray.
+        """
     def is_nodal(self, arg0: int) -> bool: ...
     @property
     def is_all_cell_centered(self) -> bool: ...