diff --git a/src/qc_qa/confidence/summary.py b/src/qc_qa/confidence/summary.py
index 72d1f7f..2c65d44 100644
--- a/src/qc_qa/confidence/summary.py
+++ b/src/qc_qa/confidence/summary.py
@@ -140,14 +140,22 @@ def compute_flagged(
         below_mask = series < threshold
         if not below_mask.any():
             continue
-        below = final_df.loc[below_mask, [c for c in (fn_col, field) if c]]
+        # Only select columns that actually exist. A <FIELD>_CONF column can
+        # survive into final_df without its sibling <FIELD> value column --
+        # e.g. an internal-only confidence-bearing column whose value side
+        # was dropped by reorder_columns. Without this guard, .loc throws
+        # KeyError: "['<FIELD>'] not in index" and crashes the run.
+        select_cols = [c for c in (fn_col, field) if c and c in final_df.columns]
+        below = final_df.loc[below_mask, select_cols]
         for idx, row in below.iterrows():
             flagged.append(
                 {
-                    "FILE_NAME": row[fn_col] if fn_col else "",
+                    "FILE_NAME": (
+                        row[fn_col] if fn_col and fn_col in below.columns else ""
+                    ),
                     "field": field,
                     "confidence": round(float(series.loc[idx]), 4),
-                    "value": "" if field not in below.columns else row.get(field, ""),
+                    "value": row.get(field, "") if field in below.columns else "",
                     "threshold": threshold,
                 }
             )