ICD-10 Guide

Unstable Angina

ICD-10 Coding for Unstable Angina(I20.0, I25.11x)

PRIMARY SPECIALTYCardiology

COMPLEXITYHigh

LAST UPDATED09/15/2025

Sam Tuffun, PT, DPT

Physical Therapist | Medical Coding & Billing Contributor

Diagnosis Overview

What is Unstable Angina?

Essential facts and insights about Unstable Angina

Key Clinical Considerations:

Chest pain or discomfort at rest or with minimal exertion
New onset of angina that is severe and frequent
Worsening pattern of previously stable angina

Clinical Information

Clinical Criteria & Documentation Requirements

Patient history including risk factors and symptom description
Results of ECG, cardiac biomarkers, and stress tests
Detailed physical exam findings including vital signs and heart sounds

Coding Guidelines

Usage Guidelines & Examples

Follow guidelines for distinguishing unstable angina from stable angina.
Common errors include misclassifying unstable angina as stable angina.

Code Exclusions

Important Exclusions

Myocardial infarction (I21.x)
Stable angina (I20.9)

Specialty Focus

Primary Specialty

Cardiology

Specialty Applications

Adults with risk factors for coronary artery disease
Emergency and outpatient cardiology settings

Coding Complexity

High Complexity

This diagnosis requires careful attention to:

Comprehensive clinical documentation
Accurate code selection based on clinical criteria
Proper exclusion considerations
Specialty-specific coding guidelines

Documentation

Documentation Templates

Billing Information

Billing Considerations

Ensure proper documentation for billing
Verify code specificity requirements
Check for any additional codes needed
Review payer-specific guidelines

Common Issues

Insufficient clinical documentation
Incorrect code selection
Missing supporting diagnoses
Timing and frequency documentation

Frequently Asked Questions

What are the documentation requirements?

Document the patient's history, symptoms, and results of diagnostic tests.

What are the billing considerations?

Ensure accurate coding to reflect the severity and urgency of the condition.

Unstable Angina

Diagnosis Overview

Key Clinical Considerations:

Clinical Information

Clinical Criteria & Documentation Requirements

Coding Guidelines

Usage Guidelines & Examples

Code Exclusions

Important Exclusions

Related ICD-10 Codes

Related CPT Codes

Specialty Focus

Primary Specialty

Specialty Applications

Coding Complexity

Documentation

Documentation Templates

Billing Information

Billing Considerations

Common Issues

Frequently Asked Questions

What are the documentation requirements?

What are the billing considerations?

Unstable Angina

Diagnosis Overview

Key Clinical Considerations:

Clinical Information

Clinical Criteria & Documentation Requirements

Coding Guidelines

Usage Guidelines & Examples

Code Exclusions

Important Exclusions

Related ICD-10 Codes

Related CPT Codes

Specialty Focus

Primary Specialty

Specialty Applications

Coding Complexity

Documentation

Documentation Templates

Billing Information

Billing Considerations

Common Issues

Frequently Asked Questions

What are the documentation requirements?

What are the billing considerations?