diff --git a/backend/src/cyclone/rebill/summary.py b/backend/src/cyclone/rebill/summary.py
index 4939216..99e22c4 100644
--- a/backend/src/cyclone/rebill/summary.py
+++ b/backend/src/cyclone/rebill/summary.py
@@ -51,7 +51,7 @@ def write_summary_csv(rows: list[SummaryRow], out_path: Path) -> int:
                 str(r.visit.billed),
                 r.disposition,
                 str(r.unpaid),
-                "|".join(r.cas_reasons),
+                "|".join(r.cas_reasons),  # pipe-separated; no collision with J-prefixed member IDs or relative file paths
                 r.file_path,
             ])
     return len(rows)
diff --git a/backend/tests/test_rebill_summary.py b/backend/tests/test_rebill_summary.py
index 5cc8c74..a78c1c8 100644
--- a/backend/tests/test_rebill_summary.py
+++ b/backend/tests/test_rebill_summary.py
@@ -39,4 +39,6 @@ def test_disposition_constants():
     assert REBILLED_A == "REBILLED_A"
     assert REBILLED_B == "REBILLED_B"
     assert EXCLUDED_CARC == "EXCLUDED_CARC"
+    assert EXCLUDED_PAYER == "EXCLUDED_PAYER"
+    assert EXCLUDED_NO_EVV == "EXCLUDED_NO_EVV"
     assert EXCLUDED_TIMELY_FILING == "EXCLUDED_TIMELY_FILING"