diff --git a/apps/Backend/src/ai/cdt-lookup.ts b/apps/Backend/src/ai/cdt-lookup.ts
index 04bf42d7..426f6475 100644
--- a/apps/Backend/src/ai/cdt-lookup.ts
+++ b/apps/Backend/src/ai/cdt-lookup.ts
@@ -229,6 +229,17 @@ const DIRECT_CODE_MAP: Record<string, string> = {
   "vertical sinus":         "D7952",
   "sinus augmentation":     "D7951",
   "bone graft":             "D4263",
+  // Partial dentures
+  "upper partial":          "D5211",
+  "upper partial denture":  "D5211",
+  "partial upper":          "D5211",
+  "partial upper denture":  "D5211",
+  "upper partial dentures": "D5211",
+  "lower partial":          "D5212",
+  "lower partial denture":  "D5212",
+  "partial lower":          "D5212",
+  "partial lower denture":  "D5212",
+  "lower partial dentures": "D5212",
   // Implant (not in MH schedule)
   "implant":                "D6010",
   "implant body":           "D6010",