ICD-10-CM 2027 diagnosis code
S90.549External constriction, unspecified ankle
S90.549 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it and add the required 7th character.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About S90.549
S90.549 is the ICD-10-CM diagnosis code for external constriction, unspecified ankle. It belongs to category S90 (superficial injury of ankle, foot and toes), block S90-S99 (injuries to the ankle and foot) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.
Within S90.54, choose S90.549 (unspecified ankle) only when documentation doesn't support a more specific option: right ankle (S90.541) and left ankle (S90.542).
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
7th character
The appropriate 7th character is to be added to each code from category S90
Notes that apply from higher levels
Instructions written at a parent level also apply to S90.549.
Broader instructions also apply from S90-S99 Injuries to the ankle and foot and Chapter 19: Injury, poisoning and certain other consequences of external causes.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about S90.549
Is S90.549 billable?
- No. S90.549 is a header code. Report one of its more specific subcodes instead.