KFF Survey of Medicaid Unwinding

This KFF Survey of Medicaid Unwinding was designed and analyzed by public opinion researchers at KFF. The survey was conducted February 15 – March 11, 2024, online and by telephone, among a nationally representative sample of 1,227 U.S. adults in English (1,167) and in Spanish (60) who had Medicaid coverage at some point between January 1 and March 31, 2023.

The sample includes 909 adults reached through the SSRS Opinion Panel either online (n=887) or over the phone (n=22). The SSRS Opinion Panel is a nationally representative probability-based panel where panel members are recruited randomly in one of two ways: (a) Through invitations mailed to respondents randomly sampled from an Address-Based Sample (ABS) provided by Marketing Systems Groups (MSG) through the U.S. Postal Service’s Computerized Delivery Sequence (CDS); (b) from a dual-frame random digit dial (RDD) sample provided by MSG. Invitations were sent to panel members who self-identified as having Medicaid in 2023 as either part of the 2023 KFF Health Insurance Consumer Survey or another SSRS Opinion Panel survey.

The sample also includes 117 telephone interviews from callbacks to phone respondents from the 2023 KFF Health Insurance Consumer Survey as well as other KFF Health Tracking Polls conducted by SSRS during which respondents self-identified as having Medicaid coverage. The KFF Health Tracking Polls include a random digit dial telephone sample of prepaid cell phone numbers obtained through MSG. Phone numbers used for the prepaid cell phone component are randomly generated from a cell phone sampling frame with disproportionate stratification aimed at reaching Hispanic and non-Hispanic Black respondents.

Another 217 respondents were reached through the Ipsos Knowledge Panel, an online probability based panel. Knowledge Panel is a nationally representative probability-based panel where members are recruited through invitations mailed to respondents randomly sampled from an Address-Based Sample. Invitations were sent to panel members who self-identified as having Medicaid in 2023.

Respondents in the phone samples received a $10 incentive via a check received by mail, and web respondents received a $10 electronic gift card incentive. Ipsos respondents were incentivized using the IPSOS incentive program that rewards respondents for participating with baseline points that can be used towards special raffles and sweepstakes with both cash rewards and other prizes to be won. The average baseline points redeemed for this study was 1000 points which is the cash equivalent value of $1.00.

The online questionnaire included two questions designed to establish that respondents were paying attention. Cases that failed both attention checks questions, those with over 30% item non-response, and cases with a length less than one quarter of the mean length, by mode, were flagged and reviewed. Cases were removed from the data if they failed two or more of these quality checks. Based on this criterion, one case was removed.

The combined phone and panel samples were weighted to match the sample’s demographics to the national U.S. adult population using data from the Census Bureau’s  March 2023 Current Population Survey Annual Social and Economic Supplement (CPS-ASEC). Weighting parameters included sex , age, education, race/ethnicity, census region, homeownership and household size. The sample was also weighted to match patterns of civic engagement, county population density, and voter registration from parameters derived from the SSRS Opinion Panel. The weights take into account differences in the probability of selection for each sample type. This includes a non-response propensity adjustment for the recontact sample frame.

The margin of sampling error including the design effect for the full sample is plus or minus 4 percentage points. Numbers of respondents and margins of sampling error for key subgroups are shown in the table below. For results based on other subgroups, the margin of sampling error may be higher. Sample sizes and margins of sampling error for other subgroups are available by request. Sampling error is only one of many potential sources of error and there may be other unmeasured error in this or any other public opinion poll. KFF public opinion and survey research is a charter member of the Transparency Initiative of the American Association for Public Opinion Research.