Inpatient Facility Coding & Compliance Alert

Question: A 56-year-old patient presents with chest pain. He is diagnosed with atherosclerotic coronary artery disease and angina. How do we code for this, using the ICD-10-CM codes?

Florida Subscriber

Answer: We know that atherosclerotic coronary artery disease and angina are distinct disease processes and thus have their own codes when they exist as a single diagnosis: I25.1 (Atherosclerotic heart disease of native coronary artery) and I20.9 (Angina pectoris, unspecified). However, coding guidelines tell us that there is an assumed causal relationship when atherosclerosis and angina pectoris are both listed as diagnoses.

Where the conditions have a causal (or assumed) relationship, ICD-10 offers the use of combination codes. Therefore, here, you should use the combination code for both diseases instead of using individual codes for each one. The code that best describes the combined diagnoses is I25.11, (Atherosclerotic heart disease of native coronary artery with angina pectoris). Remember to code an acute myocardial infarction if it exists, before the coronary artery disease. Another example of combination code is code I25.7, which includes both atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris.