Leaving Mexico by plan with Permanent or Temporal Visa card

At the airport in CDMX

Go through security in T1 where the sign is posted for gates 25-36. As you exit security  with the duty free shops on your left and the Starbucks on your right there is a kiosk for INM and you go there  with your passport and resident card. Fill out the FMM and they do the rest. No matter what your gate number is you must go here. The airline will take the bottom portion and you keep the top portion and give it to INM along with your passport and resident card when you reenter Mexico.

At the airport you are required to fill out an exit visa. The location of form can vary by airport.  At one airport I had to fill out form before checking in at counter. At other airport it is after security at an INM desk. At another airport the INM desk is on same level as check in.

Complete form, present form, passport and your current visa (tourist, temporal, permanente) to INM officer.

If you are exiting with a visa temporal/permanente the officer will give back to you a portion of the form you just completed. KEEP THIS FORM. You will need it when you RETURN to Mexico.

On return flight to MX you do not have to fill out immigration form that is passed out on plane as long as you have retained form issued when you left MX

When you return to MX. Present the portion of the form you retained, passport and visa Temporal/Permanente.

Hint: If you arrive at an airport with long lines of "tourists" (Cancun) waiting to be processed at INM, if you have a Residente Permanente visa go to the Mexican national line. If your spouse/companion has Temporal they can accompany you thru MX line.

Hope this helped.   Hopefully someone else will add to or modify my comments

I have left Mexico and/or returned through the Mexico City airport, the Guadalajara airport and the Zacatecas airport.  The procedures varied slightly on departure and return. The trips were over a year apart so I don't know if procedures changed.  I do know that land crossing at Reynosa has not changed in 8 years.  It doesn't hurt to ask what you do next at each step starting when you arrive at security. 

In Mexico City, you filled out the FMM form at the INM desk and after it was stamped and carried the form to the departure gate where the airline attendant took the smaller part and gave you back the larger part.  In Zacatecs, the INM agent gave you only the smaller part.  The gate attendant only looked at it to be sure it was stamped and had the right flight information.  In all cases you report to INM at the point of entry, land, seaport or airport and turn the portion you retained.   Your passport is stamped on departure and return.

Thanks to all for the information. GyC.

I am a permanent resident but did not complete the procedure mentioned when leaving Mexico. What do I need to do to correct this error?

Hi, since a few years now there is no form to complete but need to get your passport stamped by IMN at the last airport leaving Mexico. The exit date is entered with S (salida) at the end and RP underneath, at your return the stamp date as a E (entrada) and RP...all on the same page of your passport. This is now computerized so the authorities know all about your stays in Mexico and out of Mexico.

Basically, your passport was stamped but probably no RP id, first check what is in your passport.

The situation normally could be corrected when you come back by saying to the INM officer that you forgot and you are in an illegal position. They will resolve this issue and I don't know if you would be charged a fine or cancel your residency status.

Personally, I would contact immediately the closest Mexican consulate or embassy of this subject and learn more from the authorities.

Buena suerte para resolver su situación, GyC