diff --git a/kauldron/evals/evaluators.py b/kauldron/evals/evaluators.py
index b1c5744b..fe865e6b 100644
--- a/kauldron/evals/evaluators.py
+++ b/kauldron/evals/evaluators.py
@@ -251,7 +251,6 @@ def evaluate(
         step=step,
         aux=merged_aux,
         schedules={},
-        model_with_aux=self.model_with_aux,
         log_summaries=True,
     )
     return merged_aux
diff --git a/kauldron/train/metric_writer.py b/kauldron/train/metric_writer.py
index e506e3bb..a48c4190 100644
--- a/kauldron/train/metric_writer.py
+++ b/kauldron/train/metric_writer.py
@@ -165,7 +165,6 @@ def write_step_metrics(
       *,
       step: int,
       aux: train_step.Auxiliaries,
-      model_with_aux: train_step.ModelWithAux,
       schedules: Mapping[str, optax.Schedule],
       log_summaries: bool,
       timer: Optional[chrono_utils.Chrono] = None,
@@ -201,15 +200,7 @@ def write_step_metrics(
 
     if log_summaries:
       with jax.transfer_guard("allow"):
-        # TODO(klausg): remove once all summaries are migrated to new protocol
-        # image summaries
-        image_summaries_old = {
-            name: summary.get_images(**aux.summary_kwargs[name])
-            for name, summary in model_with_aux.summaries.items()
-            if isinstance(summary, summaries.ImageSummary)
-        }
-
-        image_summaries = image_summaries_old | {
+        image_summaries = {
             name: value
             for name, value in aux_result.summary_values.items()
             if isinstance(value, Float["n h w #3"])
@@ -586,7 +577,6 @@ def write_step_metrics(
       *,
       step: int,
       aux: train_step.Auxiliaries,
-      model_with_aux: train_step.ModelWithAux,
       schedules: Mapping[str, optax.Schedule],
       log_summaries: bool,
       timer: Optional[chrono_utils.Chrono] = None,
diff --git a/kauldron/train/train_lib.py b/kauldron/train/train_lib.py
index dda08504..f7ac85db 100644
--- a/kauldron/train/train_lib.py
+++ b/kauldron/train/train_lib.py
@@ -136,7 +136,6 @@ def train_impl(
             step=i,
             aux=aux,
             schedules=trainer.schedules,
-            model_with_aux=trainstep.model_with_aux,
             timer=chrono,
             log_summaries=log_summaries,
         )
diff --git a/kauldron/train/train_step.py b/kauldron/train/train_step.py
index d42debf4..21b61dd2 100644
--- a/kauldron/train/train_step.py
+++ b/kauldron/train/train_step.py
@@ -251,15 +251,10 @@ def init(  # pylint:disable=missing-function-docstring
   @jax.named_call
   def forward(
       self,
-      context: context_lib.Context | None = None,
+      context: context_lib.Context,
       *,
       rngs: rngs_lib.Rngs,
       is_training: bool,
-      # DEPRECATED variables: Should be passed through `context` instead.
-      params=None,
-      batch=None,
-      step: int | None = None,
-      collections: _Collections | None = None,
   ) -> tuple[float, context_lib.Context]:
     """Forward pass of the model including losses.
 
@@ -268,45 +263,12 @@ def forward(
         `batch`, `step`, and `collections` (and optionally `opt_state`).
       rngs: Random numbers to use for the forward pass.
       is_training: Whether to run the model in training or eval mode.
-      params: DEPRECATED: Should be passed through `context` instead.
-      batch: DEPRECATED: Should be passed through `context` instead.
-      step: DEPRECATED: Should be passed through `context` instead.
-      collections: DEPRECATED: Should be passed through `context` instead.
 
     Returns:
       loss_total: Total loss.
       context: Context with the updated `loss_total`, `loss_states`,
         `interms`, and `collections`.
     """
-    # New API: pass everything through `context`
-    if isinstance(context, context_lib.Context):
-      if any(v is not None for v in (params, batch, step, collections)):
-        raise ValueError(
-            "When calling `model_with_aux.forward(context)`, you should not"
-            " pass `params`, `batch`,... through kwargs, but rather through the"
-            " context."
-        )
-      # Should check that params, batch,... are correctly set in the context ?
-    else:  # Legacy API (deprecated)
-      status.log(
-          "Warning: Calling `model_with_aux.forward(params)` is deprecated and"
-          " will be removed soon. Instead, all inputs should be passed"
-          " through context directly: `model_with_aux.forward(context)`."
-      )
-      # Params can be passed either as positional or keyword arguments:
-      if context is None:  # `forward(params=params)`
-        assert params is not None, "Cannot pass both `params` and `context`"
-      else:  # `forward(params)`
-        assert params is None, "Cannot pass both `params` and `context`"
-        params = context
-
-      context = context_lib.Context(
-          step=step,
-          batch=batch,
-          params=params,
-          collections=collections,
-      )
-    del params, batch, step, collections
     args, kwargs = data_utils.get_model_inputs(self.model, context)
     preds, collections = self.model.apply(
         {"params": context.params} | context.collections,