diff --git a/.github/workflows/core_tests.yml b/.github/workflows/core_tests.yml
index 8e659b25c..3e4fd52f9 100644
--- a/.github/workflows/core_tests.yml
+++ b/.github/workflows/core_tests.yml
@@ -130,6 +130,7 @@ jobs:
 
       - run: uv run pytest test/test_skim_name_conflicts.py
       - run: uv run pytest test/random_seed/test_random_seed.py
+      - run: uv run pytest test/trace_id/test_trace_id.py
 
   builtin_regional_models:
     needs: foundation
diff --git a/activitysim/cli/run.py b/activitysim/cli/run.py
index af9a76daa..a1b23048c 100644
--- a/activitysim/cli/run.py
+++ b/activitysim/cli/run.py
@@ -9,11 +9,14 @@
 import sys
 import warnings
 from datetime import datetime
+import struct
+import time
 
 import numpy as np
 
 from activitysim.core import chunk, config, mem, timing, tracing, workflow
 from activitysim.core.configuration import FileSystem, Settings
+from activitysim.core.run_id import RunId
 
 from activitysim.abm.models.settings_checker import check_model_settings
 
@@ -29,6 +32,7 @@
     "settings_file_name",
     "imported_extensions",
     "run_timestamp",
+    "run_id",
 ]
 
 
@@ -161,6 +165,8 @@ def inject_arg(name, value):
         # 'configs', 'data', and 'output' folders by default
         os.chdir(args.working_dir)
 
+    inject_arg("run_id", state.tracing.run_id)
+
     if args.ext:
         for e in args.ext:
             basepath, extpath = os.path.split(e)
@@ -268,6 +274,7 @@ def run(args):
     """
 
     state = workflow.State()
+    _init_run_id = state.tracing.run_id
 
     # register abm steps and other abm-specific injectables
     # by default, assume we are running activitysim.abm
diff --git a/activitysim/core/configuration/top.py b/activitysim/core/configuration/top.py
index 405560810..a6c29269a 100644
--- a/activitysim/core/configuration/top.py
+++ b/activitysim/core/configuration/top.py
@@ -2,6 +2,8 @@
 
 from pathlib import Path
 from typing import Any, Literal
+import struct
+import time
 
 from pydantic import model_validator, validator
 
diff --git a/activitysim/core/mp_tasks.py b/activitysim/core/mp_tasks.py
index 42b1ab444..f54e2f8d2 100644
--- a/activitysim/core/mp_tasks.py
+++ b/activitysim/core/mp_tasks.py
@@ -19,6 +19,7 @@
 
 from activitysim.core import config, mem, tracing, util, workflow
 from activitysim.core.configuration import FileSystem, Settings
+from activitysim.core.run_id import RunId
 from activitysim.core.workflow.checkpoint import (
     CHECKPOINT_NAME,
     CHECKPOINT_TABLE_NAME,
@@ -890,6 +891,10 @@ def setup_injectables_and_logging(injectables, locutor: bool = True) -> workflow
     injects injectables
     """
     state = workflow.State()
+    _run_id = injectables.get("run_id", None)
+    if _run_id:
+        state.tracing.run_id = RunId(_run_id)
+
     state = state.initialize_filesystem(**injectables)
     state.settings = injectables.get("settings", Settings())
     state.filesystem.parse_settings(state.settings)
diff --git a/activitysim/core/run_id.py b/activitysim/core/run_id.py
new file mode 100644
index 000000000..a5d4ea1c8
--- /dev/null
+++ b/activitysim/core/run_id.py
@@ -0,0 +1,11 @@
+import struct
+import time
+
+
+class RunId(str):
+    def __new__(cls, x=None):
+        if x is None:
+            return cls(
+                hex(struct.unpack("<Q", struct.pack("<d", time.time()))[0])[-6:].lower()
+            )
+        return super().__new__(cls, x)
diff --git a/activitysim/core/workflow/tracing.py b/activitysim/core/workflow/tracing.py
index 2669e5b9b..b89a8bd26 100644
--- a/activitysim/core/workflow/tracing.py
+++ b/activitysim/core/workflow/tracing.py
@@ -5,11 +5,9 @@
 import logging
 import logging.config
 import os
-import struct
 import sys
 import tarfile
 import tempfile
-import time
 from collections.abc import Mapping, MutableMapping, Sequence
 from pathlib import Path
 from typing import Any, Optional
@@ -22,6 +20,7 @@
 from activitysim.core.test import assert_equal, assert_frame_substantively_equal
 from activitysim.core.workflow.accessor import FromState, StateAccessor
 from activitysim.core.exceptions import TableSlicingError
+from activitysim.core.run_id import RunId
 
 logger = logging.getLogger(__name__)
 
@@ -37,15 +36,6 @@
 ]
 
 
-class RunId(str):
-    def __new__(cls, x=None):
-        if x is None:
-            return cls(
-                hex(struct.unpack("<Q", struct.pack("<d", time.time()))[0])[-6:].lower()
-            )
-        return super().__new__(cls, x)
-
-
 class Tracing(StateAccessor):
     """
     Methods to provide the tracing capabilities of ActivitySim.
diff --git a/test/trace_id/.gitignore b/test/trace_id/.gitignore
new file mode 100644
index 000000000..67176c62d
--- /dev/null
+++ b/test/trace_id/.gitignore
@@ -0,0 +1,2 @@
+configs*/
+output/
\ No newline at end of file
diff --git a/test/trace_id/simulation.py b/test/trace_id/simulation.py
new file mode 100644
index 000000000..70cf3457f
--- /dev/null
+++ b/test/trace_id/simulation.py
@@ -0,0 +1,16 @@
+# ActivitySim
+# See full license in LICENSE.txt.
+
+from __future__ import annotations
+
+import argparse
+import sys
+
+from activitysim.cli.run import add_run_args, run
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    add_run_args(parser)
+    args = parser.parse_args()
+
+    sys.exit(run(args))
diff --git a/test/trace_id/test_trace_id.py b/test/trace_id/test_trace_id.py
new file mode 100644
index 000000000..4d678759e
--- /dev/null
+++ b/test/trace_id/test_trace_id.py
@@ -0,0 +1,85 @@
+from __future__ import annotations
+
+# ActivitySim
+# See full license in LICENSE.txt.
+import importlib.resources
+import os
+import subprocess
+from shutil import copytree
+
+import pandas as pd
+import pandas.testing as pdt
+import yaml
+
+
+def update_settings(settings_file, key, value):
+    with open(settings_file, "r") as f:
+        settings = yaml.safe_load(f)
+        f.close()
+
+    settings[key] = value
+
+    with open(settings_file, "w") as f:
+        yaml.safe_dump(settings, f)
+        f.close()
+
+
+def test_trace_ids_have_same_hash():
+    def example_path(dirname):
+        resource = os.path.join("examples", "prototype_mtc", dirname)
+        return str(importlib.resources.files("activitysim").joinpath(resource))
+
+    def test_path(dirname):
+        return os.path.join(os.path.dirname(__file__), dirname)
+
+    new_configs_dir = test_path("configs")
+    new_mp_configs_dir = test_path("configs_mp")
+    new_settings_file = os.path.join(new_configs_dir, "settings.yaml")
+    copytree(example_path("configs"), new_configs_dir)
+    copytree(example_path("configs_mp"), new_mp_configs_dir)
+
+    update_settings(
+        new_settings_file, "trace_hh_id", 1932009
+    )  # Household in the prototype_mtc example with 11 people
+
+    def check_csv_suffix(directory):
+        suffix = None
+        mismatched_files = []
+        for root, dirs, files in os.walk(directory):
+            for filename in files:
+                if filename.lower().endswith(".csv"):
+                    file_suffix = filename[-10:]
+                    if suffix is None:
+                        suffix = file_suffix
+                    elif file_suffix != suffix:
+                        mismatched_files.append(os.path.join(root, filename))
+        if mismatched_files:
+            raise AssertionError(
+                f"CSV files with mismatched suffixes: {mismatched_files}"
+            )
+
+    file_path = os.path.join(os.path.dirname(__file__), "simulation.py")
+
+    run_args = [
+        "-c",
+        test_path("configs_mp"),
+        "-c",
+        test_path("configs"),
+        "-d",
+        example_path("data"),
+        "-o",
+        test_path("output"),
+    ]
+
+    try:
+        os.mkdir(test_path("output"))
+    except FileExistsError:
+        pass
+
+    subprocess.run(["coverage", "run", "-a", file_path] + run_args, check=True)
+
+    check_csv_suffix(os.path.join(test_path("output"), "trace"))
+
+
+if __name__ == "__main__":
+    test_trace_ids_have_same_hash()