The 2018 Sample Adult layout file noted that, "This is a time category recode for the time since the most recent mammogram. All available information was used and the recoded variable was pre-filled with the response to the time category first, if available. These data are provided by the respondent and are not imputed."

Another variable, MAMLGYRR2 is similar, but recoded using the same method as used in the 2000 time category recoding method.