S45.009A — Unspecified injury of axillary artery, unspecified side, initial encounter
Is S45.009A billable?
Yes, but S45.009A will trip a Medicare edit. S45.009A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists S45.009A under Medicare Code Editor edit 20, “Unspecified code” — meaning a code specifying laterality (right, left or bilateral) exists in the same family. On an inpatient claim this triggers the edit, because CMS holds that there are very limited circumstances in which laterality cannot be documented.
More specific alternatives
S45.009A at a glance
| Code | S45.009A |
|---|---|
| Description | Unspecified injury of axillary artery, unspecified side, 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 S45.009A?
In S45.009A, the 7th character A means initial encounter. The 7th character is required for S45.009A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to S45.009A?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name S45.009A directly.
A code specifying laterality (right, left or bilateral) exists in the same family. CMS holds that there are very limited circumstances in which laterality cannot be documented.
Which MS-DRGs does S45.009A group to?
S45.009A 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
As a secondary diagnosis, S45.009A is a major complication or comorbidity (MCC), which can move a stay into a higher-paying DRG.
How is S45.009A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under S45.00, the nearest indexed parent of S45.009A. Use them to find the family, then select the specific code.
- Injury › blood vessel NEC › axillary › artery
Use additional code — inherited from Chapter 19
Report an additional code alongside S45.009A to fully describe the condition. S45.009A 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 S45.009A, but a patient may have both at the same time. When documentation supports it, S45.009A and the excluded code may both be reported.
Excludes2 — not included here — inherited from S40-S49
The conditions below are not part of S45.009A, but a patient may have both at the same time. When documentation supports it, S45.009A and the excluded code may both be reported.
Excludes2 — not included here — inherited from S45
The conditions below are not part of S45.009A, but a patient may have both at the same time. When documentation supports it, S45.009A and the excluded code may both be reported.
Code also — inherited from S45
Two codes may be needed to describe the condition fully. Whether S45.009A is sequenced first depends on the reason for the encounter.
- any associated open wound (S41.-)
How long has S45.009A existed?
S45.009A 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.