Hi all,

American Mexican resident here. Foreigners on tourist visas and Mexican passport holders do NOT need to do exit immigration. However, temporary and permanent residents do and therefore there is exit immigration in a small kiosk at each airport past security. If you want/need an exit stamp because of the CDC 14 day rule or for whatever reason here is what you need to do:

Once you exit security look for exit immigration in the main airside area by the gates, you'll usually see a sign that says something like " Migración (also sometimes spelled Inmigración) , Solo residentes temporales y permanentes" every international terminal in Mexico has it though the smaller ones may not be manned at all time. When you get there just tell the agent you're not a resident but would like an exit stamp and she'll be happy to stamp it for you.

p.s. If you're in Mexico on a tourist FMM and lost your exit card, this is the same place you'd want to go to get another one FYI. If you're polite they might waive the fine.