Question 1

What are the active CMS reimbursement alerts for ICD-10-CM code I48.91?

Accepted Answer

According to CLV Intelligence data, there are currently 1 active CMS and MAC reimbursement policy alerts affecting ICD-10-CM code I48.91 (Unspecified atrial fibrillation).  Alerts are sourced from CMS transmittals, Medicare Administrative Contractor (MAC) Local Coverage Determinations (LCDs), and Federal Register notices. Data is updated daily.

Question 2

What is the estimated recoverable revenue impact for practices missing CMS updates on I48.91?

Accepted Answer

According to CLV Intelligence's revenue model, practices with unmonitored CMS policy changes affecting ICD-10-CM code I48.91 (Unspecified atrial fibrillation) may expose an estimated $11,820 in recoverable annual revenue. This estimate is based on a 4% industry-standard coding error rate applied to an average annual claim volume, a $950 average Medicare allowed amount, and a 60% conservative recovery capture rate. This is a directional estimate — not a billing or legal guarantee.

Question 3

Which MAC contractors publish LCD or billing guidance for I48.91?

Accepted Answer

According to CLV Intelligence data, Local Coverage Determinations (LCDs) and billing guidance relevant to ICD-10-CM code I48.91 (Unspecified atrial fibrillation) may be issued by any of the seven Medicare Administrative Contractors (MACs): Noridian Healthcare Solutions (Jurisdictions E and F), CGS Administrators (Jurisdiction 15), Palmetto GBA (Jurisdictions J and M), NGS (Jurisdictions 6 and K), WPS Government Health Administrators (Jurisdictions 5 and 8), First Coast Service Options (Jurisdiction N), and Novitas Solutions (Jurisdictions H and L). CLV Intelligence monitors all MAC jurisdictions daily and surfaces alerts by jurisdiction so clinical coders can filter to their region.

Question 4

Is ICD-10-CM code I48.91 billable under Medicare in 2025–2026?

Accepted Answer

ICD-10-CM code I48.91 — Unspecified atrial fibrillation — is a valid billable diagnosis code under the ICD-10-CM FY2026 code set maintained by the Centers for Disease Control and Prevention (CDC) and adopted by CMS for Medicare and Medicaid billing. CLV Intelligence tracks CMS fee schedule updates, LCD revisions, and coverage policy changes that may affect reimbursement eligibility for this code. Coders should verify against the most recent MAC LCD and CMS NCCI edits before submission.

I48.91 — Unspecified atrial fibrillation

Code definition & billing validity

Coding context for I48.91

MAC coverage considerations

Active CMS & MAC policy alerts

LCD L34315: Electrocardiograms — Noridian

MAC jurisdiction coverage

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