ICD 10 Coding Alert

Don't assume -- let the inclusion notes guide your angina code choice.

When ICD-10 replaces ICD-9, you'll need to know whether cardiac angina falls under "other" or "unspecified" angina pectoris. Here are some tips to keep your coding compliant.

The diagnosis: Angina pectoris refers to chest pain or discomfort caused by coronary heart disease.

ICD-9-CM codes:

• 413.9, Other and unspecified angina pectoris

ICD-10-CM codes:

• I20.8, Other forms of angina pectoris
• I20.9, Angina pectoris, unspecified

ICD-9 coding rules: Code 413.9, as an "other and unspecified" code, is appropriate for Angina: NOS, cardiac, equivalent, of effort; angina syndrome; status anginosus; stenocardia; and syncope anginosa. You also have an instruction to use additional code(s) for symptoms associated with angina equivalent. And ICD-9 provides an excludes note, telling you to report 411.1 for preinfarction angina.

ICD-10 changes: ICD-10 splits your options, using I20.8 for "other" angina and I20.9 for "unspecified" angina. Code I20.8 will be appropriate for angina equivalent, angina of effort, coronary slow flow syndrome, and stenocardia. With I20.8, you'll "use additional code(s) for symptoms associated with angina equivalent."

Code I20.9 will be appropriate for angina NOS, anginal syndrome, cardiac angina, and ischemic chest pain.

Documentation: With ICD-10, documentation of the specific type of angina will be even more important to proper coding. You will need to format your superbill to capture the difference between "other" and "unspecified" angina pectoris. "Other" means the physician documented the type, but ICD-10 doesn't offer a code specific to the documented type. "Unspecified" means the physician did not document the type.

Coder tips: Alert the clinical staff that the superbill will change in response to the separate "other" and "unspecified" codes. Remind them that payers often deny "unspecified" codes, so specific documentation is preferred.

Additionally, as with so many ICD-10 codes, you need to be sure to check for notes that apply not just to the code, but also to the full range it belongs to. For ischemic heart diseases (I20-I25), you should use an additional code to identify presence of hypertension (I10-I15). For I20, watch these "use additional code" and Excludes1 notes:

Exposure to environmental tobacco smoke (Z77.22)

History of tobacco use (Z87.891)

Occupational exposure to environmental tobacco smoke (Z57.31)

Tobacco dependence (F17.-)

Tobacco use (Z72.0)

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).