Medicare Advantage and Prescription Drug Plan CAHPS® Survey

Scoring and Star Ratings

Scoring and Star Ratings

MA & PDP CAHPS Case-Mix Adjustment Information

MA & PDP CAHPS Survey results are adjusted for certain respondent characteristics not under the control of the health or drug plan but related to the sampled member's survey responses. Case-mix adjustment is performed by CMS contractors. The case-mix coefficients are re-estimated each year based on new data and are used for Star Ratings. For example, the case-mix coefficients for 2020 Star Ratings were estimated from CAHPS data collected in 2019. Case-mix coefficients are publicly available in the Medicare Part C & D Star Ratings Technical Notes.


2019 Information on Case-mix, Case-mix Coefficients and National Means (ZIP)

2018 Information on Case-mix, Case-mix Coefficients and National Means (ZIP)

2017 Information on Case-mix and Case-mix Coefficients

2016 Information on Case-mix and Case-mix Coefficients

2015 Information on Case-mix and Case-mix Coefficients

2014 Information on Case-mix and Case-mix Coefficients


MA & PDP CAHPS Case-Mix Variables

The variables used as case-mix adjustors for the MA & PDP CAHPS Survey since 1998 can be found here.


Scoring of MA & PDP CAHPS Composite Measures

Slides describing the scoring of composite measures for the MA & PDP CAHPS Survey can be found here.


MA & PDP CAHPS Between-Contract Variances for Reported Measures

Between-contract variances for reported measures are available since 2019.

2019 Between-Contract Variances for Reported Measures


Analysis of MA & PDP CAHPS Reported Measures and the CAHPS Macro

A summary description of the analyses that contribute to the reported measures for MA & PDP CAHPS can be found here. MA & PDP CAHPS data are analyzed using the CAHPS Macro, Version 5.0, found here.


Weighting of MA & PDP CAHPS Measures Within Contracts

Additional detail on weighting of MA & PDP CAHPS measures within contracts can be found here.


Individual-Level Weight Construction in MA & PDP CAHPS

Information on construction of individual-level weights in MA & PDP CAHPS can be found here.


Nonresponse Adjustment of the Medicare CAHPS Surveys in Research Papers Using the Individual-Level Weights

Unit response rates followed patterns typical for health surveys (Klein et al., 2011), including higher response rates for non-Hispanic whites than for other racial/ethnic subgroups, better response rates through age 79, and lower response rates for low-income beneficiaries. All analyses used individual-level poststratification weights that account for sample design and nonresponse (Deming and Stephan, 1940; Purcell and Kish, 1980) by matching weighted sample and enrollment populations in each Medicare contract-by-county combination on demographic characteristics, Medicaid eligibility/low-income subsidy enrollment status, enrollment in a Special Needs Plan, and zip-code level distributions of income, education, and race/ethnicity.



Klein DJ, Elliott MN, Haviland AM, et al. Understanding nonresponse to the 2007 Medicare CAHPS survey. Gerontologist. 2011; 51: 843–855.

Deming WE, Stephan FF. On a least squares adjustment of a sampled frequency table when the expected marginal tools are known. Ann Math Stat. 1940; 11: 427–444.

Purcell NJ, Kish L. Postcensal estimates for local areas (or domains). Int Stat Rev. 1980; 48: 3–18.


Summary of Comparison of Linear Mean Scoring with Top-Box Scoring for Medicare CAHPS Measures

Official scoring of Medicare CAHPS is linear mean scoring. A summary that compares linear mean scoring with top-box scoring for Medicare CAHPS measures can be found here. The summary includes median reliabilities for Medicare Advantage contracts calculated from 2017 CAHPS data.


Internet Citation

Please use the following citation when referencing material on this web site. [] Centers for Medicare & Medicaid Services, Baltimore, MD. Month, Date, Year the page was accessed.


This page was last modified on 3/13/2020