diff --git a/backend/app.py b/backend/app.py
index d91b6f3..670404d 100644
--- a/backend/app.py
+++ b/backend/app.py
@@ -4153,13 +4153,14 @@ def api_kims_interaction_check():
             }), 400
         
         # 1. DrugCode → BASECODE(KIMS 9자리) 변환
+        # CD_BARCODE.BASECODE가 KIMS KD코드 (9자리)
         drug_session = db_manager.get_session('PM_DRUG')
         placeholders = ','.join([f"'{c}'" for c in drug_codes])
         
         code_query = text(f"""
-            SELECT DISTINCT G.DrugCode, G.GoodsName, B.BASECODE
+            SELECT G.DrugCode, G.GoodsName, 
+                   (SELECT TOP 1 BASECODE FROM CD_BARCODE WHERE DrugCode = G.DrugCode AND BASECODE IS NOT NULL) as BASECODE
             FROM CD_GOODS G
-            LEFT JOIN CD_BARCODE B ON G.DrugCode = B.DrugCode
             WHERE G.DrugCode IN ({placeholders})
         """)
         code_result = drug_session.execute(code_query).fetchall()