---
kind: "section"
citation: "42 C.F.R. § 425.659"
title: "42"
number: "425.659"
heading: "Calculating risk scores used in Shared Savings Program benchmark calculations."
url: "https://uscodex.org/cfr/42/425.659"
---

# §425.659. Calculating risk scores used in Shared Savings Program benchmark calculations.

- (a) **General.** CMS accounts for differences in severity and case mix of the ACO's assigned beneficiaries and assignable beneficiaries (as defined under [§ 425.20](/cfr/42/425.20.md)) in calculations used in establishing, adjusting, and updating the ACO's historical benchmark.
- (b) **Prospective Hierarchical Condition Category (HCC) risk score calculation.** In determining Medicare FFS beneficiary prospective HCC risk scores for a performance year and each benchmark year of the ACO's agreement period, CMS does the following:
  - (1) CMS specifies the CMS-HCC risk adjustment methodology used to calculate prospective HCC risk scores for Medicare FFS beneficiaries (as defined under [§ 425.20](/cfr/42/425.20.md)) for use in Shared Savings Program calculations as follows:
    - (i) In calculating risk scores for Medicare FFS beneficiaries for a performance year, CMS applies the CMS-HCC risk adjustment methodology applicable for the corresponding calendar year.
    - (ii) For agreement periods beginning before January 1, 2024, CMS applies the CMS-HCC risk adjustment methodology for the calendar year corresponding to the benchmark year in calculating risk scores for Medicare FFS beneficiaries for each benchmark year of the agreement period.
    - (iii) For agreement periods beginning on January 1, 2024, and in subsequent years, CMS applies the CMS-HCC risk adjustment methodology for the calendar year corresponding to the performance year, as specified under [paragraph (b)(1)(i)](#b-1-i) of this section, in calculating risk scores for Medicare FFS beneficiaries for each benchmark year of the agreement period.
  - (2) CMS does the following to calculate the prospective HCC risk scores identified in [paragraph (b)(1)](#b-1) of this section for a benchmark or performance year:
    - (i) **Removes the Medicare Advantage coding intensity adjustment, if applicable.**
    - (ii) Renormalizes prospective HCC risk scores by Medicare enrollment type (ESRD, disabled, aged/dual eligible Medicare and Medicaid beneficiaries, and aged/non-dual eligible Medicare and Medicaid beneficiaries) based on the national assignable FFS population for the relevant benchmark or performance year.
    - (iii) Calculates the average prospective HCC risk score by Medicare enrollment type (ESRD, disabled, aged/dual eligible Medicare and Medicaid beneficiaries, and aged/non-dual eligible Medicare and Medicaid beneficiaries).

## Notes

### Amendments

[88 FR 79551, Nov. 16, 2023]

### Authority

Authority: 42 U.S.C. 1302, 1306, 1395hh, and 1395jjj.

### Source

Source: 76 FR 67973, Nov. 2, 2011, unless otherwise noted.

### Amendments

[88 FR 79551, Nov. 16, 2023]