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 HCC 238 neither supersedes nor is superseded by any other category, so it always counts alongside unrelated HCCs.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 (living at home, age 65 or over, not also enrolled in Medicaid). 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.
