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