ICD-10 Code for Atrial Fibrillation (AFib)
Also searched as a fib
The ICD-10-CM code for atrial fibrillation (AFib) is I48.91 — Unspecified atrial fibrillation. It is billable for FY2027.
Atrial fibrillation ICD-10 codes at a glance
| Condition | Atrial fibrillation (AFib) |
|---|---|
| Code | I48.91 — Unspecified atrial fibrillation |
| Billable | Yes (I48.91) |
| Alphabetic Index entry | Fibrillation, atrial or auricular |
| Code set | ICD-10-CM FY2027, valid October 1, 2026 – September 30, 2027 |
What changes the atrial fibrillation code?
The Alphabetic Index lists these qualifiers under Fibrillation, atrial or auricular. If the record documents one of them, the code changes. Verify the code in the Tabular List before reporting it.
| chronic | I48.20 | Chronic atrial fibrillation, unspecified |
| chronic › persistent | I48.19 | Other persistent atrial fibrillation |
| paroxysmal | I48.0 | Paroxysmal atrial fibrillation |
| permanent | I48.21 | Permanent atrial fibrillation |
| persistent | I48.19 | Other persistent atrial fibrillation |
| persistent › longstanding | I48.11 | Longstanding persistent atrial fibrillation |
What does the Tabular List say about I48.91?
The instructional notes that govern I48.91, including those it inherits from its category and chapter. An Excludes1 note means the two codes are never reported together.
Excludes2 — not included here — inherited from Chapter 9
The conditions below are not part of I48.91, but a patient may have both at the same time. When documentation supports it, I48.91 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- systemic connective tissue disorders (M30-M36)
- transient cerebral ischemic attacks and related syndromes (G45.-)
Codes, descriptions and Index entries are from the official ICD-10-CM FY2027 release. Guideline text is quoted from the ICD-10-CM Official Guidelines for Coding and Reporting FY 2027. A code must always be verified in the Tabular List before it is reported. Data sources