Hello,
I’m trying to understand the dual health insurance sources coded in variables PRXMM (monthly coverage through a federal or state Marketplace) and MAMMX (edited monthly Medicaid/CHIP coverage) in the MEPS panel data. I’ve noticed that, for some individuals, both variables are coded as “yes” for the same month. Please see the attached screenshot for an example–the respondent is coded as having health insurance from both Medicaid/CHIP and Marketplace in each month in 2018.
Could someone please explain how dual health insurance sources should be interpreted, and what the recommended approach is for identifying the primary source of coverage?
Thanks for your help in advance.
I took a closer look at the data and was able to confirm your findings. Specifically, I am seeing 192 persons in the 2018 full year consolidated file who reported at least one month of concurrent enrollment in both a federal or state marketplace and in Medicaid/CHIP. The most common case is a single month of overlap (71 cases). This type of overlap is expected during transition between coverage types. This is because coverage is indicated as long as the respondent reported at least a single day of enrollment within the month. The remaining cases are more unclear; IPUMS does not have a recommended approach and leaves the decision on how to identify the primary source of coverage to individual researchers.
Broadly speaking, you may consider there being two possibilities that explain what is happening. The first is that this is the result of misreporting on the part of the interviewer or interviewee. This is possible since enrollment is self-reported by MEPS participants and is not verified against administrative records. The second possibility is that this indicates true dual enrollment. While federal rules state that persons who are eligible for health coverage through Medicaid or CHIP cannot get subsidized marketplace coverage, from my understanding it is possible to remain enrolled in a marketplace program without a subsidy. You may consider reaching out to an expert at the Agency for Healthcare Research and Quality (AHRQ) for further guidance.
@Ivan_Strahof, thank you for taking the time to replicate my analysis and explaining the potential reasons behind dual enrollments.
