ICD-10-CM 2027
ICD-10 code for unstable angina
From the official ICD-10-CM alphabetic index entry “Angina (attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor) › unstable”. Page updated September 29, 2026.
About coding unstable angina
The ICD-10-CM code for unstable angina is I20.0 (Unstable angina).
Within I20 (angina pectoris), I20.0 is specifically for unstable angina. Related codes cover with documented spasm (I20.1), refractory angina pectoris (I20.2), other forms of angina pectoris (I20.8) and unspecified (I20.9).
Use an additional code to identify: exposure to environmental tobacco smoke (Z77.22), history of tobacco dependence (Z87.891), occupational exposure to environmental tobacco smoke (Z57.31), tobacco dependence (F17.-) and tobacco use (Z72.0).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
Common questions about unstable angina ICD-10 codes
What is the ICD-10 code for unstable angina?
- I20.0 — Unstable angina.
Is I20.0 billable?
- Yes. I20.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I20.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I20.0 as a principal diagnosis.
Is I20.0 a CC or MCC?
- I20.0 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.