diff --git a/tensorflow_privacy/privacy/privacy_tests/membership_inference_attack/data_structures.py b/tensorflow_privacy/privacy/privacy_tests/membership_inference_attack/data_structures.py
index 3e4e8d3..93f87f0 100644
--- a/tensorflow_privacy/privacy/privacy_tests/membership_inference_attack/data_structures.py
+++ b/tensorflow_privacy/privacy/privacy_tests/membership_inference_attack/data_structures.py
@@ -20,7 +20,7 @@ import glob
 import logging
 import os
 import pickle
-from typing import Any, Iterable, MutableSequence, Optional, Union, Sequence
+from typing import Any, Dict, Iterable, MutableSequence, Optional, Sequence, Union
 
 import numpy as np
 import pandas as pd
@@ -116,6 +116,12 @@ class SlicingSpec:
   all_custom_train_indices: Optional[Sequence[np.ndarray]] = None
   all_custom_test_indices: Optional[Sequence[np.ndarray]] = None
 
+  # Specifies names for custom slices. The names will be in the output in
+  # SingleAttackResult.slice_spec.value. If provided, the dictionary must
+  # contain names for all custom indices groups from all_custom_train_indices
+  # and all_custom_test_indices.
+  custom_slices_names: Optional[Dict[int, str]] = None
+
   def __post_init__(self):
     if not self.all_custom_train_indices and not self.all_custom_test_indices:
       return
diff --git a/tensorflow_privacy/privacy/privacy_tests/membership_inference_attack/dataset_slicing.py b/tensorflow_privacy/privacy/privacy_tests/membership_inference_attack/dataset_slicing.py
index 95b609a..ab486d4 100644
--- a/tensorflow_privacy/privacy/privacy_tests/membership_inference_attack/dataset_slicing.py
+++ b/tensorflow_privacy/privacy/privacy_tests/membership_inference_attack/dataset_slicing.py
@@ -264,9 +264,13 @@ def get_single_slice_specs(
             f"Too many groups ({groups.size}) for slicing by custom indices. "
             f"Should be no more than {_MAX_NUM_OF_SLICES}.")
       for g in groups:
-        result.append(
-            SingleSliceSpec(SlicingFeature.CUSTOM,
-                            (custom_train_indices, custom_test_indices, g)))
+        if slicing_spec.custom_slices_names is not None:
+          if g not in slicing_spec.custom_slices_names:
+            raise ValueError(f"Custom slice={g} is not in custom_slices_names")
+          group_id = slicing_spec.custom_slices_names[g]
+        else:
+          group_id = (custom_train_indices, custom_test_indices, g)
+        result.append(SingleSliceSpec(SlicingFeature.CUSTOM, group_id))
   return result