Medical care for foreigners can be complicated. Mexico has a multi tier health system. From the ones mentioned by Mexwanderer to top notch private hospitals. I am not sure if a tourist can apply for Seguro Popular. You might need a Residente Temporal not an FMM. I would not want it regardless. Some of their clinics are 3rd world. Even IMSS varies from good care to horrible. They run out of medicines mid month and none of the new drugs are on their list. Many of the private hospitals are as good as first class USA facilities. But they are not cheap like IMSS. Specialists charge around 800 pesos for a consult. Still inexpensive by US standards. Tourist areas have private hospitals with signs stating they speak English and take credit cards. Avoid these facilities . They are known to rip off customers with fees that approach Scottsdale prices but health care that is 3rd rate. I think that Sharp Hospital is one of those facilities. We use CIMA in Hermosillo and they are great. As was mentioned when it is time to leave the hospital an armed guard accompanies you to the accounting office!
Moisheh