ICD-10-CM > S00-T88 > T66-T78 > T70 > T70.2 T70.2 Other and unspecified effects of high altitude Non-Billable/Non-Specific Type 2 Excludes polycythemia due to high altitude (D75.1) Codes T70.20Unspecified effects of high altitudeT70.20XA..., initial encounterT70.20XD..., subsequent encounterT70.20XS..., sequelaT70.29Other effects of high altitudeT70.29XA..., initial encounterT70.29XD..., subsequent encounterT70.29XS..., sequela