diff --git a/imap_processing/codice/codice_l1a.py b/imap_processing/codice/codice_l1a.py
index 794c09730..fba72d288 100644
--- a/imap_processing/codice/codice_l1a.py
+++ b/imap_processing/codice/codice_l1a.py
@@ -27,10 +27,8 @@
 )
 from imap_processing.codice.codice_l1a_lo_priority import l1a_lo_priority
 from imap_processing.codice.codice_l1a_lo_species import l1a_lo_species
-from imap_processing.codice.utils import (
-    CODICEAPID,
-    process_by_table_id,
-)
+from imap_processing.codice.constants import CODICEAPID
+from imap_processing.codice.utils import process_by_table_id
 from imap_processing.utils import packet_file_to_datasets
 
 logger = logging.getLogger(__name__)
diff --git a/imap_processing/codice/codice_l1a_de.py b/imap_processing/codice/codice_l1a_de.py
index 25e437594..5fbba71f8 100644
--- a/imap_processing/codice/codice_l1a_de.py
+++ b/imap_processing/codice/codice_l1a_de.py
@@ -7,9 +7,9 @@
 
 from imap_processing.cdf.imap_cdf_manager import ImapCdfAttributes
 from imap_processing.codice import constants
+from imap_processing.codice.constants import CODICEAPID
 from imap_processing.codice.decompress import decompress
 from imap_processing.codice.utils import (
-    CODICEAPID,
     CoDICECompression,
     ViewTabInfo,
     apply_replacements_to_attrs,
diff --git a/imap_processing/codice/codice_l1a_lo_priority.py b/imap_processing/codice/codice_l1a_lo_priority.py
index 34a32349a..1603d8b18 100644
--- a/imap_processing/codice/codice_l1a_lo_priority.py
+++ b/imap_processing/codice/codice_l1a_lo_priority.py
@@ -8,10 +8,9 @@
 
 from imap_processing.cdf.imap_cdf_manager import ImapCdfAttributes
 from imap_processing.codice import constants
-from imap_processing.codice.constants import HALF_SPIN_FILLVAL
+from imap_processing.codice.constants import CODICEAPID, HALF_SPIN_FILLVAL
 from imap_processing.codice.decompress import decompress
 from imap_processing.codice.utils import (
-    CODICEAPID,
     CoDICECompression,
     calculate_acq_time_per_step,
     get_codice_epoch_time,
diff --git a/imap_processing/codice/codice_l1a_lo_species.py b/imap_processing/codice/codice_l1a_lo_species.py
index d5f9fbeef..187d0aa2c 100644
--- a/imap_processing/codice/codice_l1a_lo_species.py
+++ b/imap_processing/codice/codice_l1a_lo_species.py
@@ -9,13 +9,13 @@
 from imap_processing.cdf.imap_cdf_manager import ImapCdfAttributes
 from imap_processing.codice import constants
 from imap_processing.codice.constants import (
+    CODICEAPID,
     HALF_SPIN_FILLVAL,
     LO_IALIRT_VARIABLE_NAMES,
     LO_SW_SPECIES_VARIABLE_NAMES,
 )
 from imap_processing.codice.decompress import decompress
 from imap_processing.codice.utils import (
-    CODICEAPID,
     CoDICECompression,
     calculate_acq_time_per_step,
     get_codice_epoch_time,
diff --git a/imap_processing/codice/constants.py b/imap_processing/codice/constants.py
index 49eed824e..e0604bc56 100644
--- a/imap_processing/codice/constants.py
+++ b/imap_processing/codice/constants.py
@@ -13,11 +13,50 @@
 ESA = ElectroStatic Analyzer
 """
 
+from enum import IntEnum
 from typing import Any
 
 import numpy as np
 
-from imap_processing.codice.utils import CODICEAPID
+
+class CODICEAPID(IntEnum):
+    """Create ENUM for CoDICE APIDs."""
+
+    COD_AUT = 1120
+    COD_BOOT_HK = 1121
+    COD_BOOT_MEMDMP = 1122
+    COD_COUNTS_COMMON = 1135
+    COD_NHK = 1136
+    COD_EVTMSG = 1137
+    COD_MEMDMP = 1138
+    COD_SHK = 1139
+    COD_RTS = 1141
+    COD_DIAG_CDHFPGA = 1144
+    COD_DIAG_SNSR_HV = 1145
+    COD_DIAG_OPTC_HV = 1146
+    COD_DIAG_APDFPGA = 1147
+    COD_DIAG_SSDFPGA = 1148
+    COD_DIAG_FSW = 1149
+    COD_DIAG_SYSVARS = 1150
+    COD_LO_IAL = 1152
+    COD_LO_PHA = 1153
+    COD_LO_SW_PRIORITY_COUNTS = 1155
+    COD_LO_SW_SPECIES_COUNTS = 1156
+    COD_LO_NSW_SPECIES_COUNTS = 1157
+    COD_LO_SW_ANGULAR_COUNTS = 1158
+    COD_LO_NSW_ANGULAR_COUNTS = 1159
+    COD_LO_NSW_PRIORITY_COUNTS = 1160
+    COD_LO_INST_COUNTS_AGGREGATED = 1161
+    COD_LO_INST_COUNTS_SINGLES = 1162
+    COD_HI_IAL = 1168
+    COD_HI_PHA = 1169
+    COD_HI_INST_COUNTS_AGGREGATED = 1170
+    COD_HI_INST_COUNTS_SINGLES = 1171
+    COD_HI_OMNI_SPECIES_COUNTS = 1172
+    COD_HI_SECT_SPECIES_COUNTS = 1173
+    COD_HI_INST_COUNTS_PRIORITIES = 1174
+    COD_CSTOL_CONFIG = 2457
+
 
 # -------L1A Constants-------
 # Numerical constants
diff --git a/imap_processing/codice/utils.py b/imap_processing/codice/utils.py
index c4854f428..52527c018 100644
--- a/imap_processing/codice/utils.py
+++ b/imap_processing/codice/utils.py
@@ -15,6 +15,7 @@
 import xarray as xr
 
 from imap_processing.codice import constants
+from imap_processing.codice.constants import CODICEAPID
 
 
 @dataclass
@@ -46,45 +47,6 @@ class ViewTabInfo:
     view_id: int
 
 
-class CODICEAPID(IntEnum):
-    """Create ENUM for CoDICE APIDs."""
-
-    COD_AUT = 1120
-    COD_BOOT_HK = 1121
-    COD_BOOT_MEMDMP = 1122
-    COD_COUNTS_COMMON = 1135
-    COD_NHK = 1136
-    COD_EVTMSG = 1137
-    COD_MEMDMP = 1138
-    COD_SHK = 1139
-    COD_RTS = 1141
-    COD_DIAG_CDHFPGA = 1144
-    COD_DIAG_SNSR_HV = 1145
-    COD_DIAG_OPTC_HV = 1146
-    COD_DIAG_APDFPGA = 1147
-    COD_DIAG_SSDFPGA = 1148
-    COD_DIAG_FSW = 1149
-    COD_DIAG_SYSVARS = 1150
-    COD_LO_IAL = 1152
-    COD_LO_PHA = 1153
-    COD_LO_SW_PRIORITY_COUNTS = 1155
-    COD_LO_SW_SPECIES_COUNTS = 1156
-    COD_LO_NSW_SPECIES_COUNTS = 1157
-    COD_LO_SW_ANGULAR_COUNTS = 1158
-    COD_LO_NSW_ANGULAR_COUNTS = 1159
-    COD_LO_NSW_PRIORITY_COUNTS = 1160
-    COD_LO_INST_COUNTS_AGGREGATED = 1161
-    COD_LO_INST_COUNTS_SINGLES = 1162
-    COD_HI_IAL = 1168
-    COD_HI_PHA = 1169
-    COD_HI_INST_COUNTS_AGGREGATED = 1170
-    COD_HI_INST_COUNTS_SINGLES = 1171
-    COD_HI_OMNI_SPECIES_COUNTS = 1172
-    COD_HI_SECT_SPECIES_COUNTS = 1173
-    COD_HI_INST_COUNTS_PRIORITIES = 1174
-    COD_CSTOL_CONFIG = 2457
-
-
 class CoDICECompression(IntEnum):
     """Create ENUM for CoDICE compression algorithms."""
 
@@ -246,7 +208,17 @@ def process_by_table_id(
     ]
     if len(processed) == 1:
         return processed[0]
-    return xr.concat(processed, dim="epoch").sortby("epoch")
+    # Keep non-epoch support variables as it is, 1-D arrays,
+    # instead of expanding them along the epoch dimension.
+    # Eg. voltage_table and k_factor are 1-D arrays that apply to all
+    # epochs in the same way.
+    return xr.concat(
+        processed,
+        dim="epoch",
+        data_vars="minimal",
+        coords="minimal",
+        compat="equals",
+    ).sortby("epoch")
 
 
 def get_collapse_pattern_shape(
diff --git a/imap_processing/tests/codice/test_process_by_table_id.py b/imap_processing/tests/codice/test_process_by_table_id.py
new file mode 100644
index 000000000..3fe28d21d
--- /dev/null
+++ b/imap_processing/tests/codice/test_process_by_table_id.py
@@ -0,0 +1,41 @@
+"""Unit tests for CoDICE table-id grouping helpers."""
+
+from pathlib import Path
+
+import numpy as np
+import xarray as xr
+
+from imap_processing.codice.utils import process_by_table_id
+
+
+def test_process_by_table_id_keeps_voltage_table_1d():
+    """Shared support data should not be expanded across epoch groups."""
+
+    unpacked_dataset = xr.Dataset(
+        data_vars={
+            "view_id": ("epoch", np.array([0, 0], dtype=np.int16)),
+            "pkt_apid": ("epoch", np.array([1156, 1156], dtype=np.int16)),
+            "plan_id": ("epoch", np.array([7, 7], dtype=np.int16)),
+            "plan_step": ("epoch", np.array([3, 3], dtype=np.int16)),
+            "table_id": ("epoch", np.array([1, 2], dtype=np.int16)),
+            "sample": ("epoch", np.array([11, 22], dtype=np.int16)),
+        },
+        coords={"epoch": np.array([20, 10], dtype=np.int64)},
+    )
+
+    voltage_table = np.array([1.0, 2.0, 3.0], dtype=np.float64)
+
+    def _process_fn(group_ds, lut_file, table_id, view_id, apid, plan_id, plan_step):
+        return xr.Dataset(
+            data_vars={
+                "sample": ("epoch", group_ds["sample"].values),
+                "voltage_table": ("esa_step", voltage_table),
+            },
+            coords={"epoch": group_ds["epoch"].values, "esa_step": np.arange(3)},
+        )
+
+    processed = process_by_table_id(unpacked_dataset, Path("unused.json"), _process_fn)
+
+    assert processed["epoch"].values.tolist() == [10, 20]
+    assert processed["voltage_table"].dims == ("esa_step",)
+    np.testing.assert_array_equal(processed["voltage_table"].values, voltage_table)