ICD-10 I48.20
Billable / Specific HCC v28: 96 CCChronic atrial fibrillation, unspecified
About ICD-10-CM I48.20
ICD-10-CM code I48.20 represents Chronic atrial fibrillation, unspecified. This is a billable/specific code in the Circulatory System chapter (block I48). The 2026 edition of ICD-10-CM I48.20 became effective on October 1, 2025.
Coding Tips for I48.20
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
I48.20 is a CMS-HCC v28 risk-adjustment code (category 96). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
I48.20 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Type 1 Excludes
Pure excludes, these codes can never be coded together with I48.20. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- Chronic persistent atrial fibrillation (I48.19)
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Inpatient DRG Impact, CC
codes Chronic atrial fibrillation, unspecified. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for I48.20
Local Coverage Determinations (LCDs) from CMS MACs that list I48.20 as a covered diagnosis.
Showing top 10 of 620 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing I48.20.
1 Aetna
5 Medicare
CPT Codes Commonly Billed with I48.20
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 83090 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
- 83700 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
- 82172 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
- 86141 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
- 83701 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
- 83719 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
- 83721 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
- 83698 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
- 83695 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
- 83704 CMS LCD: Billing and Coding: MolDX: Biomarkers in Cardiovascular Risk Assessment CMS LCD
Codes Adjacent To I48.20
Other codes in section I30-I5A (Other forms of heart disease).
ICD-10 I48.20, Billing FAQ
Is ICD-10 code I48.20 billable? +
Yes, I48.20 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What codes are Type 1 Excludes for I48.20? +
Type 1 Excludes (never code together with I48.20): Chronic persistent atrial fibrillation (I48.19)
Does I48.20 affect Medicare Advantage HCC risk adjustment? +
Yes. I48.20 maps to CMS-HCC v28 category 96. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is I48.20 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What CPT codes are commonly billed with I48.20? +
Procedures frequently paired with I48.20 include: 83090, 83700, 82172, 86141, 83701.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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