What is the ICD-10 (International Classification of Diseases, 10th Revision) code for a stress test in cardiology?

ICD-10 Coding for Cardiac Stress Testing

The ICD-10 code for a stress test in cardiology is not a single code but depends on the clinical indication for ordering the test. You must code the reason for the test (the diagnosis or symptom), not the test itself.

Primary Coding Principle

Code the clinical indication that justifies the stress test, not the procedure. The stress test is a diagnostic procedure and should be coded using CPT codes for billing purposes, while ICD-10 codes document the medical necessity 1.

Common ICD-10 Codes for Stress Test Indications

For Symptomatic Patients

• R07.9 - Chest pain, unspecified (most common for acute chest pain evaluation) 1
• R07.89 - Other chest pain (for atypical chest pain presentations) 1
• I20.9 - Angina pectoris, unspecified (for suspected or known stable angina) 1
• I20.8 - Other forms of angina pectoris (for variant or atypical angina patterns) 1
• I25.10 - Atherosclerotic heart disease of native coronary artery without angina pectoris (for known CAD without current symptoms) 1

For Risk Stratification

• Z13.6 - Encounter for screening for cardiovascular disorders (for asymptomatic screening in high-risk patients, though this is controversial for coverage) 2
• I25.10 - Atherosclerotic heart disease (for known CAD requiring risk assessment) 1
• E78.01 - Familial hypercholesterolemia (for severe dyslipidemia, though stress testing may not be covered without symptoms) 2

For Post-Procedure Follow-up

• Z95.1 - Presence of aortocoronary bypass graft (for post-CABG evaluation) 1
• Z95.5 - Presence of coronary angioplasty implant and graft (for post-PCI evaluation) 1
• I25.2 - Old myocardial infarction (for post-MI risk stratification) 1

Critical Coverage Considerations

Insurance coverage requires appropriate clinical indications documented with ICD-10 codes. 2, 3

• Symptomatic patients with chest pain (R07.x codes) or suspected angina (I20.x codes) generally meet medical necessity criteria 1, 3
• Asymptomatic screening (Z13.6) typically does NOT meet coverage criteria, even with severe risk factors like dyslipidemia >220 mg/dL 2
• Intermediate-risk patients with acute chest pain after negative troponin require either stress testing or CCTA, coded with R07.x 1

Common Pitfalls to Avoid

• Never code Z01.810 (encounter for preprocedural cardiovascular examination) as the primary diagnosis for stress testing—this is for preoperative clearance only and may not be covered 3
• Do not use screening codes (Z13.6) for asymptomatic patients without documented symptoms, as this will likely result in denial 2
• Avoid coding the stress test result (like "abnormal stress test") as the primary diagnosis—code the clinical indication that prompted the test 1
• For patients with uninterpretable ECG (left bundle branch block, paced rhythm), document this with I44.7 or Z95.0 as secondary codes, but the primary code should still be the clinical indication 1, 3

Documentation Requirements

The medical record must support the ICD-10 code selected. 1

• Document chest pain characteristics (substernal, exertional, relieved by rest/nitroglycerin) to justify angina codes 1
• Record pre-test probability of CAD (low, intermediate, high) to support testing appropriateness 1
• Note whether baseline ECG is interpretable for ischemia (affects test selection but not primary diagnosis code) 1
• Include functional capacity assessment (METs) and any disabling comorbidities that affect test modality choice 1