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S04.22XA

S04.22XAInjury of trochlear nerve, left side, initial encounter

Billable / specific codeICD-10-CMleft

S04.22XA is a billable, specific ICD-10-CM code for injury of trochlear nerve, left side, 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 S04

A
initial encounter
D
subsequent encounter
S
sequela

Risk adjustment

S04.22XA 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

S04.22XA is named in 5 Medicare coverage policies 5 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A54095Billing and Coding: Nerve Conduction Studies and Electromyography
  • A56612Billing and Coding: CT of the Head
  • A56773Billing and Coding: Neurophysiology Evoked Potentials (NEPs)
  • A57123Billing and Coding: Nerve Conduction Studies and Electromyography

Code history

S04.22XA 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 S04.22. If S04.22XA is not quite right, the correct code is usually one of these.

Questions about S04.22XA

Is S04.22XA a billable ICD-10-CM code?
Yes. S04.22XA is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does S04.22XA sit in the tabular list?
Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Injuries to the head (S00-S09).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.