Interviewers asked for the date of birth and age of each reporting unit member. AHRQ then calculated exact age from date of birth. In cases where the calculated age and the age provided did not match, AHRQ staff reviewed and resolved inconsistencies. When respondents did not provide the date of birth but did provide age, AHRQ assigned the month and year of birth randomly from among the possible valid options. For any remaining cases with missing age information, AHRQ imputed age using:

In 2018, AHRQ assigned two respondents missing values on BIRTHMO and BIRTHYR in the public use file. According to communication between IPUMS MEPS and AHRQ staff, those respondents were assigned missing values as "a result of confidentiality recoding due to perturbations as required by the National Center for Health Statistics." IPUMS MEPS recoded the values of those two cases to "Unknown-Not Ascertained," although they are coded as "Unknown-Don't Know" in the original MEPS public use data.