No, but you will need it to do other things; like get your CURP card, for example. The CURP will then be needed to buy a cell phone or a chip to make yours work in Mexico. I can't remember, but it might also be needed when you apply for your DIF and INAPAM cards so that you can enjoy the benefits of being a senior citizen and getting certain discounts from 5% on medications to 50% on bus tickets.