diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4fc2600ea..ee6dad30e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,7 +17,10 @@ PLEASE REMEMBER TO CHANGE THE '..main' WITH AN ACTUAL TAG in GITHUB LINK.
     Please use `jax.experimental.maps.Mesh`. Please see https://jax.readthedocs.io/en/latest/_autosummary/jax.experimental.maps.Mesh.html#jax.experimental.maps.Mesh
     for more information.
   * {func}`jax.numpy.take_along_axis` now takes an optional `mode` parameter
-    that specifies the behavior of out-of-bounds indexing.
+    that specifies the behavior of out-of-bounds indexing. By default,
+    invalid values (e.g., NaN) will be returned for out-of-bounds indices. In
+    previous versions of JAX, invalid indices were clamped into range. The
+    previous behavior can be restored by passing `mode="clip"`.
   * {func}`jax.numpy.take_along_axis` now raises a `TypeError` if its indices
     are not of an integer type, matching the behavior of
     {func}`numpy.take_along_axis`. Previously non-integer indices were silently
diff --git a/jax/_src/numpy/lax_numpy.py b/jax/_src/numpy/lax_numpy.py
index cab728fac..9d1ef2be6 100644
--- a/jax/_src/numpy/lax_numpy.py
+++ b/jax/_src/numpy/lax_numpy.py
@@ -3431,10 +3431,9 @@ def _normalize_index(index, axis_size):
 TAKE_ALONG_AXIS_DOC = """
 Unlike :func:`numpy.take_along_axis`, :func:`jax.numpy.take_along_axis` takes
 an optional ``mode`` parameter controlling how out-of-bounds indices should be
-handled. By default, out-of-bounds indices are clamped into range. In a future
-change, out-of-bounds indices will return invalid (e.g., ``NaN``) values
-instead. See :attr:`jax.numpy.ndarray.at` for more discussion
-of out-of-bounds indexing in JAX.
+handled. By default, out-of-bounds indices yield invalid values (e.g., ``NaN``).
+See :attr:`jax.numpy.ndarray.at` for futrher discussion of out-of-bounds
+indexing in JAX.
 """
 
 @_wraps(np.take_along_axis, update_doc=False,
@@ -3520,9 +3519,8 @@ def take_along_axis(arr, indices, axis: Optional[int],
     offset_dims=tuple(offset_dims),
     collapsed_slice_dims=tuple(collapsed_slice_dims),
     start_index_map=tuple(start_index_map))
-  # TODO(phawkins): change the mode to "fill".
   return lax.gather(arr, gather_indices, dnums, tuple(slice_sizes),
-                    mode="clip" if mode is None else mode)
+                    mode="fill" if mode is None else mode)
 
 ### Indexing
 
diff --git a/tests/lax_numpy_test.py b/tests/lax_numpy_test.py
index a635f07d7..0a3ab07d2 100644
--- a/tests/lax_numpy_test.py
+++ b/tests/lax_numpy_test.py
@@ -4577,15 +4577,16 @@ class LaxBackedNumpyTests(jtu.JaxTestCase):
     x = jnp.arange(10, dtype=jnp.float32)
     idx = jnp.array([-11, -10, -9, -5, -1, 0, 1, 5, 9, 10, 11])
     out = jnp.take_along_axis(x, idx, axis=0)
-    expected_clip = np.array([0, 0, 1, 5, 9, 0, 1, 5, 9, 9, 9], np.float32)
-    np.testing.assert_array_equal(expected_clip, out)
-    out = jnp.take_along_axis(x, idx, axis=0, mode="clip")
-    np.testing.assert_array_equal(expected_clip, out)
     expected_fill = np.array([jnp.nan, 0, 1, 5, 9, 0, 1, 5, 9, jnp.nan,
                               jnp.nan], np.float32)
+    np.testing.assert_array_equal(expected_fill, out)
     out = jnp.take_along_axis(x, idx, axis=0, mode="fill")
     np.testing.assert_array_equal(expected_fill, out)
 
+    expected_clip = np.array([0, 0, 1, 5, 9, 0, 1, 5, 9, 9, 9], np.float32)
+    out = jnp.take_along_axis(x, idx, axis=0, mode="clip")
+    np.testing.assert_array_equal(expected_clip, out)
+
   def testTakeAlongAxisRequiresIntIndices(self):
     x = jnp.arange(5)
     idx = jnp.array([3.], jnp.float32)