Is ICD-10-CM code I20 billable?

No, I20 (Angina pectoris) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code I20 belong to?

I20 belongs to Chapter 9 of the ICD-10-CM tabular list: I00–I99 (Diseases of the Circulatory System).

I20Not billable, use a more specific code below

Angina pectoris

In Ischemic heart diseases (I20-I25), chapter 9: Diseases of the Circulatory System

6 billable codes under I20: 3 are a CC; 1 map to HCC 229 (Unstable Angina and Other Acute Ischemic Heart Disease).A CC or MCC (major CC) is a secondary diagnosis that raises the MS-DRG payment. An HCC counts toward a Medicare Advantage patient's risk score.

Instructional notes

Excludes1: not coded here, use a different code

angina pectoris with atherosclerotic heart disease of native coronary arteries (I25.1-)
atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris (I25.7-)
postinfarction angina (I23.7)

Use additional code: add a second code for this, listed after this one

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.-)
tobacco use (Z72.0)

Also applies, from Ischemic heart diseases (I20-I25)

These notes sit on I20-I25 and apply to every code under it, including I20.

Code also: add a code for this too, order depends on the encounter

the presence of hypertension (I10-I1A)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Section I.C.9.b Atherosclerotic Coronary Artery Disease and Angina (page 52), covers I20
Combination codes I25.11 and I25.7 include angina, so no separate angina code is needed, and a causal link is assumed unless documented otherwise. If admitted for an AMI, sequence the AMI before the coronary artery disease.

All codes under I20

I20 can't be used on a claim. Pick a billable code below; grey headings group them.

I20 MS-DRG

As the principal diagnosis, all 6 billable codes under I20 group to MS-DRG 311 (v44.0).

DRG 311 Angina Pectoris

Other codes that refer to I20

Notes on these codes point to I20.

I24 Excludes1: angina pectoris (I20.-)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

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.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.