diff --git a/README.md b/README.md
index fbe28d0e..035bcc49 100644
--- a/README.md
+++ b/README.md
@@ -100,7 +100,7 @@ If you would like to reference Brax in a publication, please use:
   author = {C. Daniel Freeman and Erik Frey and Anton Raichuk and Sertan Girgin and Igor Mordatch and Olivier Bachem},
   title = {Brax - A Differentiable Physics Engine for Large Scale Rigid Body Simulation},
   url = {http://github.com/google/brax},
-  version = {0.9.4},
+  version = {0.10.0},
   year = {2021},
 }
 ```
diff --git a/brax/__init__.py b/brax/__init__.py
index facac60c..e2084154 100644
--- a/brax/__init__.py
+++ b/brax/__init__.py
@@ -14,7 +14,7 @@
 
 """Import top-level classes and functions here for encapsulation/clarity."""
 
-__version__ = '0.9.4'
+__version__ = '0.10.0'
 
 from brax.base import Motion
 from brax.base import State
diff --git a/brax/contact.py b/brax/contact.py
index 757824b1..6afe2362 100644
--- a/brax/contact.py
+++ b/brax/contact.py
@@ -35,8 +35,7 @@ def get(sys: System, x: Transform) -> Optional[Contact]:
   Returns:
     Contact pytree
   """
-  # TODO: use mjx.ncon.
-  ncon = mjx._src.collision_driver.ncon(sys)
+  ncon = mjx.ncon(sys)
   if not ncon:
     return None
 
diff --git a/brax/io/json.py b/brax/io/json.py
index 2b90c5f8..45598479 100644
--- a/brax/io/json.py
+++ b/brax/io/json.py
@@ -156,7 +156,7 @@ def dumps(sys: System, states: List[State]) -> Text:
   for id_ in range(sys.ngeom):
     link_idx = sys.geom_bodyid[id_] - 1
 
-    rgba = sys.mj_model.geom_rgba[id_]
+    rgba = sys.geom_rgba[id_]
     if (rgba == [0.5, 0.5, 0.5, 1.0]).all():
       # convert the default mjcf color to brax default color
       rgba = np.array([0.4, 0.33, 0.26, 1.0])
@@ -171,8 +171,7 @@ def dumps(sys: System, states: List[State]) -> Text:
     }
 
     if geom['name'] in ('Mesh', 'Box'):
-      # TODO: use sys.geom_dataid.
-      vert, face = _get_mesh(sys.mj_model, sys.mj_model.geom_dataid[id_])
+      vert, face = _get_mesh(sys.mj_model, sys.geom_dataid[id_])
       geom['vert'] = vert
       geom['face'] = face
 
diff --git a/brax/io/mjcf.py b/brax/io/mjcf.py
index fdfe16df..68512f99 100644
--- a/brax/io/mjcf.py
+++ b/brax/io/mjcf.py
@@ -385,25 +385,32 @@ def load_model(mj: mujoco.MjModel) -> System:
   )
 
   # create actuators
+  # TODO: swap brax actuation for mjx actuation model.
   ctrl_range = mj.actuator_ctrlrange
   ctrl_range[~(mj.actuator_ctrllimited == 1), :] = np.array([-np.inf, np.inf])
   force_range = mj.actuator_forcerange
   force_range[~(mj.actuator_forcelimited == 1), :] = np.array([-np.inf, np.inf])
-  q_id = np.array([mj.jnt_qposadr[i] for i in mj.actuator_trnid[:, 0]])
-  qd_id = np.array([mj.jnt_dofadr[i] for i in mj.actuator_trnid[:, 0]])
   bias_q = mj.actuator_biasprm[:, 1] * (mj.actuator_biastype != 0)
   bias_qd = mj.actuator_biasprm[:, 2] * (mj.actuator_biastype != 0)
+  # mask actuators since brax only supports joint transmission types
+  act_mask = mj.actuator_trntype == mujoco.mjtTrn.mjTRN_JOINT
+  trnid = mj.actuator_trnid[act_mask, 0].astype(np.uint32)
+  q_id = mj.jnt_qposadr[trnid]
+  qd_id = mj.jnt_dofadr[trnid]
+  act_kwargs = {
+      'gain': mj.actuator_gainprm[:, 0],
+      'gear': mj.actuator_gear[:, 0],
+      'ctrl_range': ctrl_range,
+      'force_range': force_range,
+      'bias_q': bias_q,
+      'bias_qd': bias_qd,
+  }
+  act_kwargs = jax.tree_map(lambda x: x[act_mask], act_kwargs)
 
-  # TODO: remove brax actuators
   actuator = Actuator(  # pytype: disable=wrong-arg-types
       q_id=q_id,
       qd_id=qd_id,
-      gain=mj.actuator_gainprm[:, 0],
-      gear=mj.actuator_gear[:, 0],
-      ctrl_range=ctrl_range,
-      force_range=force_range,
-      bias_q=bias_q,
-      bias_qd=bias_qd,
+      **act_kwargs
   )
 
   # create non-pytree params.  these do not live on device directly, and they
diff --git a/brax/io/mjcf_test.py b/brax/io/mjcf_test.py
index b4f0f181..a70caa4c 100644
--- a/brax/io/mjcf_test.py
+++ b/brax/io/mjcf_test.py
@@ -18,6 +18,7 @@
 from absl.testing import absltest
 from brax import test_utils
 from brax.io import mjcf
+import mujoco
 import numpy as np
 
 assert_almost_equal = np.testing.assert_array_almost_equal
@@ -131,6 +132,14 @@ def test_world_fromto(self):
     sys = test_utils.load_fixture('world_fromto.xml')
     mjcf.validate_model(sys.mj_model)
 
+  def test_loads_different_transmission(self):
+    """Tests that the brax model loads with different transmission types."""
+    mj = test_utils.load_fixture_mujoco('ant.xml')
+    mj.actuator_trntype[0] = mujoco.mjtTrn.mjTRN_SITE
+    mjcf.load_model(mj)  # loads without raising an error
+
+    with self.assertRaisesRegex(NotImplementedError, 'transmission types'):
+      mjcf.validate_model(mj)  # raises an error
 
 if __name__ == '__main__':
   absltest.main()
diff --git a/docs/release-notes/next-release.md b/docs/release-notes/next-release.md
index 14069ed7..ca4ecb57 100644
--- a/docs/release-notes/next-release.md
+++ b/docs/release-notes/next-release.md
@@ -1,5 +1 @@
 # Brax Release Notes
-
-* Rebase brax System and State onto mjx.Model and mjx.Data.
-* Use the MuJoCo renderer instead of pytinyrenderer for brax.io.image.
-* Separate validation logic from the model loader in brax.io.mjcf.
diff --git a/docs/release-notes/v0.10.0.md b/docs/release-notes/v0.10.0.md
new file mode 100644
index 00000000..971caa4a
--- /dev/null
+++ b/docs/release-notes/v0.10.0.md
@@ -0,0 +1,9 @@
+# Brax v0.10.0 Release Notes
+
+This minor release makes several changes to the brax API, such that [MJX](https://mujoco.readthedocs.io/en/stable/mjx.html) data structures are the core data structures used in brax. This allows for more seamless model loading from `MuJoCo` XMLs, and allows for running `MJX` physics more seamlessly in brax.
+
+* Rebase brax `System` and `State` onto `mjx.Model` and `mjx.Data`.
+* Separate validation logic from the model loading logic in `brax.io.mjcf`. This allows users to load an [MJX](https://mujoco.readthedocs.io/en/stable/mjx.html) model in brax, without hitting validation errors for other physics backends like `positional` and `spring`.
+* Remove `System.geoms`, since `brax.System` inherits from `mjx.Model` and all geom information is available in `mjx.Model`. We also update the brax viewer to work with this new schema.
+* Delete the brax contact library and use the contact library from `MJX`.
+* Use the MuJoCo renderer instead of pytinyrenderer for `brax.io.image`.
diff --git a/setup.py b/setup.py
index ba333181..2bdd1613 100644
--- a/setup.py
+++ b/setup.py
@@ -24,7 +24,7 @@
 
 setup(
     name="brax",
-    version="0.9.4",
+    version="0.10.0",
     description="A differentiable physics engine written in JAX.",
     author="Brax Authors",
     author_email="no-reply@google.com",