S99.921A — Unspecified injury of right foot, initial encounter
Is S99.921A billable?
Yes, but S99.921A is an unspecified code. S99.921A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, S99.921A 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 S99.921A.
S99.921A at a glance
| Code | S99.921A |
|---|---|
| Description | Unspecified injury of right foot, 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 S99.921A?
In S99.921A, the 7th character A means initial encounter. The 7th character is required for S99.921A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does S99.921A group to?
S99.921A sits in MDC 21 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 913Traumatic Injury with MCCmedical
- 914Traumatic Injury without MCCmedical
How is S99.921A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under S99.92, the nearest indexed parent of S99.921A. Use them to find the family, then select the specific code.
- Injury › foot
- Injury › toe
Use additional code — inherited from Chapter 19
Report an additional code alongside S99.921A to fully describe the condition. S99.921A 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 S99.921A, but a patient may have both at the same time. When documentation supports it, S99.921A and the excluded code may both be reported.
Excludes2 — not included here — inherited from S90-S99
The conditions below are not part of S99.921A, but a patient may have both at the same time. When documentation supports it, S99.921A and the excluded code may both be reported.
How long has S99.921A existed?
S99.921A 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.