diff --git a/src/kbmod/region_search.py b/src/kbmod/region_search.py
index 16f9300a3..97a895571 100644
--- a/src/kbmod/region_search.py
+++ b/src/kbmod/region_search.py
@@ -14,6 +14,7 @@ def _chunked_data_ids(dataIds, chunk_size=200):
     for i in range(0, len(dataIds), chunk_size):
         yield dataIds[i : i + chunk_size]
 
+
 class RegionSearch:
     """
     A class for searching through a dataset for data suitable for KBMOD processing,
@@ -34,7 +35,7 @@ def __init__(
         dataset_types,
         butler=None,
         visit_info_str="Exposure.visitInfo",
-        parallel=False,
+        max_workers=None,
         fetch_data=False,
     ):
         """
@@ -50,9 +51,9 @@ def __init__(
             The Butler object to use for data access. If None, a new Butler object will be created from `repo_path`.
         visit_info_str : `str`
             The name used when querying the butler for VisitInfo for exposures. Default is "Exposure.visitInfo".
-        parallel : `bool`
-            If True, use parallel processing where possible. Note that each parallel worker
-            will instantiate its own Butler objects, Default is False.
+        max_workers : `int`, optional
+            The maximum number of workers to use in parallel processing. Note that each parallel worker will instantiate its own Butler
+            objects. If not provided, parallel processing is disabled.
         fetch_data: `bool`, optional
             If True, fetch the VDR data when the object is created. Default is True.
         """
@@ -65,7 +66,7 @@ def __init__(
         self.collections = collections
         self.dataset_types = dataset_types
         self.visit_info_str = visit_info_str
-        self.parallel = parallel
+        self.max_workers = max_workers
 
         # Create an empty table to store the VDR (Visit, Detector, Region) data from the butler.
         self.vdr_data = Table()
@@ -128,6 +129,9 @@ def get_dataset_type_freq(butler=None, repo_path=None, collections=None):
 
         return ref_freq
 
+    def is_parallel(self):
+        return self.max_workers is not None
+
     def new_butler(self):
         """Instantiates a new Butler object from the repo_path."""
         return dafButler.Butler(self.repo_path)
@@ -294,7 +298,7 @@ def get_uris(self, data_ids, dataset_types=None, collections=None):
                 raise ValueError("No collections specified")
             collections = self.collections
 
-        if not self.parallel:
+        if not self.is_parallel():
             return self.get_uris_serial(data_ids, dataset_types, collections)
 
         # Divide the data_ids into chunks to be processed in parallel
@@ -302,7 +306,7 @@ def get_uris(self, data_ids, dataset_types=None, collections=None):
 
         # Use a ProcessPoolExecutor to fetch URIs in parallel
         uris = []
-        with ProcessPoolExecutor(max_workers=multiprocessing.cpu_count()) as executor:
+        with ProcessPoolExecutor(max_workers=self.max_workers) as executor:
             futures = [
                 executor.submit(
                     self.get_uris_serial,
diff --git a/tests/test_region_search.py b/tests/test_region_search.py
index fbfb758df..f8197b503 100644
--- a/tests/test_region_search.py
+++ b/tests/test_region_search.py
@@ -43,16 +43,13 @@ def setUp(self):
             self.default_collections,
             self.default_datasetTypes,
             butler=self.butler,
-            parallel=False,
         )
 
     def test_init(self):
         """
         Test that the region search object can be initialized.
         """
-        rs = region_search.RegionSearch(
-            MOCK_REPO_PATH, [], [], butler=self.butler, parallel=False, fetch_data=False
-        )
+        rs = region_search.RegionSearch(MOCK_REPO_PATH, [], [], butler=self.butler, fetch_data=False)
         self.assertTrue(rs is not None)
         self.assertEqual(0, len(rs.vdr_data))  # No data should be fetched
 
@@ -190,7 +187,7 @@ def func(repo_path):
             self.default_collections,
             self.default_datasetTypes,
             butler=self.butler,
-            parallel=False,  # TODO Turn on after fixing pickle issue for mocked objects
+            # TODO Turn on after fixing pickle issue for mocked objects
         )
 
         uris = parallel_rs.get_uris(data_ids)