2026 ICD-10-CM Diagnosis Code I20.1Angina pectoris with documented spasm

ICD-10-CM Codes›I00–I99›I20-I25›I20

ICD-10-CM I20.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I20.1 is a billable ICD-10-CM diagnosis code for angina pectoris with documented spasm. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as arteriospasm. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Coronary atherosclerosis and other heart disease.

This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such chest pain.

Code Identity

ICD-10-CM Code
I20.1
Billable Status
Yes — Valid for Submission
Code Describes
Angina pectoris with documented spasm
Short Description
Angina pectoris with documented spasm
Same as the full description in the CMS dataset.
Parent Code
I20
Angina pectoris

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI20-I25Ischemic heart diseases
CategoryI20Angina pectoris
This CodeI20.1Angina pectoris with documented spasm

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arteriospasm
  • Cardiac arrhythmia due to coronary artery spasm
  • Coronary artery spasm
  • Prinzmetal angina
  • Vasospasm

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Angiospastic angina
  • Prinzmetal angina
  • Spasm-induced angina
  • Variant angina

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Angina(attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor)
      • with
        • documented spasm
    • Ischemia, ischemic
      • supply (coronary)
        • due to vasospasm
    • Prinzmetal angina
    • Spasm(s), spastic, spasticity
      • cardiac
    • Spasm(s), spastic, spasticity
      • coronary (artery)
    • Spasm(s), spastic, spasticity
      • heart
    • Vasospasm(vasoconstriction)
      • coronary

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR CIR011
Coronary atherosclerosis and other heart disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Arteriospasm

    an abnormal spasm of an artery.

  • Coronary Vasospasm

    sudden coronary artery smooth muscle contraction leading to lumen constriction and decreased blood flow.

  • Vasospasm

    sudden and often, paroxysmal contractions of the muscular wall of blood vessels.

Patient EducationClinical

Angina

Angina is chest pain or discomfort you feel when there is not enough blood flow to your heart muscle. Your heart muscle needs the oxygen that the blood carries. Angina may feel like pressure or a squeezing pain in your chest. It may feel like indigestion. You may also feel pain in your shoulders, arms, neck, jaw, or back.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert I20.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
413.1 Prinzmetal angina
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About I20.1Overview

Is I20.1 (Angina pectoris) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report angina pectoris with documented spasm on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of I20.1?

Under the General Equivalence Mappings, angina pectoris with documented spasm converts to ICD-9-CM 413.1 (prinzmetal angina). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.