ICD-10-CM 2027
ICD-10 code for altitude effects high
From the official ICD-10-CM alphabetic index entry “High › altitude effects”. Page updated September 29, 2026.
About coding altitude effects high
The ICD-10-CM code for altitude effects high is T70.20 (Unspecified effects of high altitude). The official index lists 4 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on T70.20.
Within T70.2, choose T70.20 (Unspecified effects of high altitude) only when documentation doesn't support a more specific option: other effects of high altitude (T70.29).
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.
More specific altitude effects high codes (official index)
Common questions about altitude effects high ICD-10 codes
What is the ICD-10 code for altitude effects high?
- T70.20 — Unspecified effects of high altitude (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: T70.29, T70.0, T70.1, D75.1.
What is the ICD-10 code for anoxia altitude effects high?
- T70.29 — Other effects of high altitude (header code; choose a more specific subcode).
What is the ICD-10 code for polycythemia altitude effects high?
- D75.1 — Secondary polycythemia.
Is T70.20 billable?
- No. T70.20 is a header code. Report one of its more specific subcodes instead.