I work before for the IMSS ( instituto mexicano del seguro social) for more than 20 years, his is the institution of health offering the seguro popular, This a program to offer health care at low rates, includes doctor visits, medication, hospitalization and surgery, but not pension, regular mexicans workers have all this plus pension program, but alots a people was living with out a health program, so the gobermant create this one, for gringos who travel to mexico this be great becaused in case of accident o emergency you can have care a low cost, you pay at the office of IMSS a flat payment for one year, and they give you a number and with this number you can have medicalk care in all the country, is not the best service but like I said for emergency is the best medical service in Mexico, I hope I help you with this info,,,, and how this IMSS work?? is a 3 part program, the 33.3 % is paid by federal goberment, 33.3% is paid for employers, and the last 33.3 % is paid for the mexican worker, in this case americans are not mexican workers, so only pay a flat fee for a year I am not sure but is around 100 bucks, (not sure), good luck...