S85.161A — Unspecified injury of posterior tibial artery, right leg, initial encounter
S85.161A is a billable, specific ICD-10-CM code for unspecified injury of posterior tibial artery, right leg, initial encounter. It is valid for submission on a claim.
7th character "A" — initial encounter
The appropriate 7th character is to be added to each code from category S85
- A
- initial encounter
- D
- subsequent encounter
- S
- sequela
Excludes2 inherited from the categories above S85.161A
Also inherited, and the opposite of Excludes1: these conditions are not part of S85.161A, but a patient can have both, so you may code both.
Risk adjustment
S85.161A does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
S85.161A is named in 2 Medicare coverage policies — 2 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A56758Billing and Coding: Non-Invasive Vascular Studies
- A56775Billing and Coding: Magnetic Resonance Angiography
Code history
S85.161A has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.
Related codes at this level
Codes that share S85.161. If S85.161A is not quite right, the correct code is usually one of these.
Questions about S85.161A
- Is S85.161A a billable ICD-10-CM code?
- Yes. S85.161A is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does S85.161A sit in the tabular list?
- Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Injuries to the knee and lower leg (S80-S89).