diff --git a/gen3/external/nih/utils.py b/gen3/external/nih/utils.py
index e01eb304..e07cfcc6 100644
--- a/gen3/external/nih/utils.py
+++ b/gen3/external/nih/utils.py
@@ -7,8 +7,8 @@
 # For more details about this regex, see the function that uses it
 DBGAP_ACCESSION_REGEX = (
     "(?P<phsid>phs(?P<phsid_number>[0-9]+))"
-    "(.(?P<participant_set>p(?P<participant_set_number>[0-9]+))){0,1}"
     "(.(?P<version>v(?P<version_number>[0-9]+))){0,1}"
+    "(.(?P<participant_set>p(?P<participant_set_number>[0-9]+))){0,1}"
     "(.(?P<consent>c(?P<consent_number>[0-9]+)+)){0,1}"
 )
 
diff --git a/tests/test_utils.py b/tests/test_utils.py
new file mode 100644
index 00000000..cea5a94f
--- /dev/null
+++ b/tests/test_utils.py
@@ -0,0 +1,105 @@
+import pytest
+
+from gen3.external.nih.utils import get_dbgap_accession_as_parts
+
+
+@pytest.mark.parametrize("test_input, expected", [
+    (
+        'phs000123',
+        {
+            'phsid': 'phs000123',
+            'phsid_number': '000123',
+            'version': '',
+            'version_number': '',
+            'participant_set': '',
+            'participant_set_number': '',
+            'consent': '',
+            'consent_number': ''
+        }
+    ),
+    (
+        'phs000123.p1.c3',
+        {
+            'phsid': 'phs000123',
+            'phsid_number': '000123',
+            'version': '',
+            'version_number': '',
+            'participant_set': 'p1',
+            'participant_set_number': '1',
+            'consent': 'c3',
+            'consent_number': '3'
+        }
+    ),
+    (
+        'phs000123.v3.c3',
+        {
+            'phsid': 'phs000123',
+            'phsid_number': '000123',
+            'version': 'v3',
+            'version_number': '3',
+            'participant_set': '',
+            'participant_set_number': '',
+            'consent': 'c3',
+            'consent_number': '3'
+        }
+    ),
+    (
+        'phs000123.v3.p1.c3',
+        {
+            'phsid': 'phs000123',
+            'phsid_number': '000123',
+            'version': 'v3',
+            'version_number': '3',
+            'participant_set': 'p1',
+            'participant_set_number': '1',
+            'consent': 'c3',
+            'consent_number': '3'
+        }
+    ),
+    # Unexpected order of v, p, and c
+    (
+        'phs000123.p3.v1.c3',
+        {
+            'phsid': 'phs000123',
+            'phsid_number': '000123',
+            'version': '',
+            'version_number': '',
+            'participant_set': 'p3',
+            'participant_set_number': '3',
+            'consent': '',
+            'consent_number': ''
+        }
+    ),
+    (
+        'phs000123.v3.c1.p3',
+        {
+            'phsid': 'phs000123',
+            'phsid_number': '000123',
+            'version': 'v3',
+            'version_number': '3',
+            'participant_set': '',
+            'participant_set_number': '',
+            'consent': 'c1',
+            'consent_number': '1'
+        }
+    ),
+    (
+        'phs000123.p3.v1',
+        {
+            'phsid': 'phs000123',
+            'phsid_number': '000123',
+            'version': '',
+            'version_number': '',
+            'participant_set': 'p3',
+            'participant_set_number': '3',
+            'consent': '',
+            'consent_number': ''
+        }
+    ),
+])
+def test_get_dbgap_accession_as_parts(test_input, expected):
+    """
+    Test dbgap accession parsing works and outputs expected fields and values.
+    """
+
+    assert get_dbgap_accession_as_parts(test_input) == expected
\ No newline at end of file