diff --git a/activitysim/abm/models/trip_mode_choice.py b/activitysim/abm/models/trip_mode_choice.py
index f7c20800f..4aad9dda6 100644
--- a/activitysim/abm/models/trip_mode_choice.py
+++ b/activitysim/abm/models/trip_mode_choice.py
@@ -228,6 +228,7 @@ def trip_mode_choice(
             trace_choice_name="trip_mode_choice",
             estimator=estimator,
             compute_settings=model_settings.compute_settings,
+            explicit_chunk_size=model_settings.explicit_chunk,
         )
 
         if state.settings.trace_hh_id:
diff --git a/activitysim/abm/models/util/mode.py b/activitysim/abm/models/util/mode.py
index d82dd09ea..22b32dccb 100644
--- a/activitysim/abm/models/util/mode.py
+++ b/activitysim/abm/models/util/mode.py
@@ -36,6 +36,7 @@ def mode_choice_simulate(
     trace_column_names=None,
     estimator: Optional[Estimator] = None,
     compute_settings: ComputeSettings | None = None,
+    explicit_chunk_size: float = 0,
 ):
     """
     common method for  both tour_mode_choice and trip_mode_choice
@@ -74,6 +75,7 @@ def mode_choice_simulate(
         estimator=estimator,
         trace_column_names=trace_column_names,
         compute_settings=compute_settings,
+        explicit_chunk_size=explicit_chunk_size,
     )
 
     # for consistency, always return dataframe, whether or not logsums were requested
@@ -176,6 +178,7 @@ def run_tour_mode_choice_simulate(
         trace_column_names=trace_column_names,
         estimator=estimator,
         compute_settings=model_settings.compute_settings,
+        explicit_chunk_size=model_settings.explicit_chunk,
     )
 
     return choices
diff --git a/activitysim/core/configuration/logit.py b/activitysim/core/configuration/logit.py
index a1c305e53..0561c4b0d 100644
--- a/activitysim/core/configuration/logit.py
+++ b/activitysim/core/configuration/logit.py
@@ -200,6 +200,14 @@ class TemplatedLogitComponentSettings(LogitComponentSettings, extra="forbid"):
     segment-specific names.
     """
 
+    explicit_chunk: float = 0
+    """
+    If > 0, use this fixed chunk size (number of chooser rows) instead of adaptive
+    chunking. If less than 1, use this fraction of the total number of rows. Plumbed
+    through mode_choice_simulate -> simple_simulate so mode-choice models can be chunked
+    (default 0 = unchanged chunkless/adaptive behavior).
+    """
+
 
 class LocationComponentSettings(BaseLogitComponentSettings):
     """
diff --git a/activitysim/core/simulate.py b/activitysim/core/simulate.py
index 3f4ff0d30..7293d180e 100644
--- a/activitysim/core/simulate.py
+++ b/activitysim/core/simulate.py
@@ -1719,6 +1719,7 @@ def simple_simulate(
     trace_choice_name=None,
     trace_column_names=None,
     compute_settings: ComputeSettings | None = None,
+    explicit_chunk_size: float = 0,
 ):
     """
     Run an MNL or NL simulation for when the model spec does not involve alternative
@@ -1737,7 +1738,9 @@ def simple_simulate(
         chooser_chunk,
         chunk_trace_label,
         chunk_sizer,
-    ) in chunk.adaptive_chunked_choosers(state, choosers, trace_label):
+    ) in chunk.adaptive_chunked_choosers(
+        state, choosers, trace_label, explicit_chunk_size=explicit_chunk_size
+    ):
         choices = _simple_simulate(
             state,
             chooser_chunk,