S36.400A — Unspecified injury of duodenum, initial encounter
Is S36.400A billable?
Yes, but S36.400A is an unspecified code. S36.400A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, S36.400A is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting S36.400A — the more specific alternatives are listed below.
S36.400A at a glance
| Code | S36.400A |
|---|---|
| Description | Unspecified injury of duodenum, initial encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter |
What does the 7th character "A" mean in S36.400A?
In S36.400A, the 7th character A means initial encounter. The 7th character is required for S36.400A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does S36.400A group to?
S36.400A sits in MDC 06 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 393Other Digestive System Diagnoses with MCCmedical
- 394Other Digestive System Diagnoses with CCmedical
- 395Other Digestive System Diagnoses without CC/MCCmedical
As a secondary diagnosis, S36.400A is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is S36.400A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under S36.400, the nearest indexed parent of S36.400A. Use them to find the family, then select the specific code.
- Injury › intestine › small › duodenum
Use additional code — inherited from Chapter 19
Report an additional code alongside S36.400A to fully describe the condition. S36.400A is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of S36.400A, but a patient may have both at the same time. When documentation supports it, S36.400A and the excluded code may both be reported.
Excludes2 — not included here — inherited from S30-S39
The conditions below are not part of S36.400A, but a patient may have both at the same time. When documentation supports it, S36.400A and the excluded code may both be reported.
Code also — inherited from S36
Two codes may be needed to describe the condition fully. Whether S36.400A is sequenced first depends on the reason for the encounter.
- any associated open wound (S31.-)
How long has S36.400A existed?
S36.400A has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.