I48.91 — Unspecified atrial fibrillation
I48.91 is a billable, specific ICD-10-CM code for unspecified atrial fibrillation. It is valid for submission on a claim.
Risk adjustment
I48.91 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:
- HCC 238 Specified Heart Arrhythmias0.299 RAF
Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.
Medicare coverage
I48.91 is named in 39 Medicare coverage policies — 39 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52868Billing and Coding: Transesophageal Echocardiography (TEE)
- A52868Billing and Coding: Transesophageal Echocardiography (TEE)
- A54831Billing and Coding: Single Chamber and Dual Chamber Permanent Cardiac Pacemaker
- A54909Billing and Coding: Single Chamber and Dual Chamber Permanent Cardiac Pacemakers
How I48.91 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to I48.91.
- Fibrillation›atrial or auricular(established)
Related codes at this level
Codes that share I48.9. If I48.91 is not quite right, the correct code is usually one of these.
Questions about I48.91
- Is I48.91 a billable ICD-10-CM code?
- Yes. I48.91 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does I48.91 sit in the tabular list?
- Diseases of the circulatory system (I00-I99), in the block Other forms of heart disease (I30-I5A).