| Code | Description |
| C17.0 | Malignant neoplasm of duodenum |
| C7A.010 | Malignant carcinoid tumor of the duodenum |
| D13.2 | Benign neoplasm of duodenum |
| D3A.010 | Benign carcinoid tumor of the duodenum |
| K31.5 | Obstruction of duodenum |
| K31.6 | Fistula of stomach and duodenum |
| K31.7 | Polyp of stomach and duodenum |
| K31.811 | Angiodysplasia of stomach and duodenum with bleeding |
| K31.819 | Angiodysplasia of stomach and duodenum without bleeding |
| K31.82 | Dieulafoy lesion (hemorrhagic) of stomach and duodenum |
| K31.89 | Other diseases of stomach and duodenum |
| K31.9 | Disease of stomach and duodenum, unspecified |
| Q41.0 | Congenital absence, atresia and stenosis of duodenum |
| S36.400A | Unspecified injury of duodenum, initial encounter |
| S36.400D | Unspecified injury of duodenum, subsequent encounter |
| S36.400S | Unspecified injury of duodenum, sequela |
| S36.410A | Primary blast injury of duodenum, initial encounter |
| S36.410D | Primary blast injury of duodenum, subsequent encounter |
| S36.410S | Primary blast injury of duodenum, sequela |
| S36.420A | Contusion of duodenum, initial encounter |
| S36.420D | Contusion of duodenum, subsequent encounter |
| S36.420S | Contusion of duodenum, sequela |
| S36.430A | Laceration of duodenum, initial encounter |
| S36.430D | Laceration of duodenum, subsequent encounter |
| S36.430S | Laceration of duodenum, sequela |
| S36.490A | Other injury of duodenum, initial encounter |
| S36.490D | Other injury of duodenum, subsequent encounter |
| S36.490S | Other injury of duodenum, sequela |