HCC 238: Specified Heart Arrhythmias ICD-10-CM
CMS-HCC Category 238 (Specified Heart Arrhythmias) is a payment HCC in the V28 Medicare Advantage risk adjustment model. For payment year 2026 it adds a risk adjustment factor between 0.245 and 0.407 to a beneficiary's RAF score depending on the payment segment (0.299 for a community, non-dual, aged enrollee). 17 ICD-10-CM diagnosis codes map to HCC 238. It sits at the top of its hierarchy: no other condition category supersedes it.
RAF Weight by Payment Segment 7 segments
| Payment Segment | Relative Factor |
|---|---|
| Community, non-dual, aged | 0.299 |
| Community, partial-benefit dual, aged | 0.293 |
| Community, full-benefit dual, aged | 0.407 |
| Community, non-dual, disabled | 0.296 |
| Community, partial-benefit dual, disabled | 0.261 |
| Community, full-benefit dual, disabled | 0.304 |
| Institutional | 0.245 |
A beneficiary is scored in exactly one segment, set by Medicaid (dual) status, aged or disabled entitlement, and residence. Factors are relative weights, not dollar amounts; new-enrollee segments score on demographics only. HCC 238 neither supersedes nor is superseded by any other category, so it always counts alongside unrelated HCCs.
ICD-10-CM Codes That Map to HCC 238 17 codes
- I44.2 Atrioventricular block, complete from V24 HCC 96
- I47.0 Re-entry ventricular arrhythmia from V24 HCC 96
- I47.20 Ventricular tachycardia, unspecified from V24 HCC 96
- I47.21 Torsades de pointes from V24 HCC 96
- I47.29 Other ventricular tachycardia from V24 HCC 96
- I47.9 Paroxysmal tachycardia, unspecified from V24 HCC 96
- I48.0 Paroxysmal atrial fibrillation from V24 HCC 96
- I48.11 Longstanding persistent atrial fibrillation from V24 HCC 96
- I48.19 Other persistent atrial fibrillation from V24 HCC 96
- I48.20 Chronic atrial fibrillation, unspecified from V24 HCC 96
- I48.21 Permanent atrial fibrillation from V24 HCC 96
- I48.3 Typical atrial flutter from V24 HCC 96
- I48.4 Atypical atrial flutter from V24 HCC 96
- I48.91 Unspecified atrial fibrillation from V24 HCC 96
- I48.92 Unspecified atrial flutter from V24 HCC 96
- I49.2 Junctional premature depolarization from V24 HCC 96
- I49.5 Sick sinus syndrome from V24 HCC 96
Every code above carries the full HCC 238 weight when documented and reported on a Medicare Advantage encounter. The code link opens its full page with the complete risk adjustment card.
Questions About HCC 238
What is HCC 238 in the CMS-HCC model?
HCC 238 is CMS-HCC Category 238 (Specified Heart Arrhythmias) in the V28 risk adjustment model. It covers 17 ICD-10-CM diagnosis codes that raise a Medicare Advantage beneficiary's risk score when documented.
What is the RAF weight for HCC 238?
For payment year 2026, HCC 238 adds 0.299 to the RAF score of a community, non-dual, aged beneficiary. The published weights range from 0.245 to 0.407 across the seven payment segments shown above.
Related References
Source: Centers for Medicare & Medicaid Services, Payment Year 2026 risk adjustment mapping and model software releases (CMS-HCC V28), applied to the FY 2026 ICD-10-CM code set. ICD List is not affiliated with CMS.
