IMSS (Instituto Mexicano Seguro Social) is available to Temporary and Permanent Residents. Renewals are annual and fees may be as high as 20,500 pesos, depending on one’s age. Those with pre-existing conditions, which may be as common as high blood pressure or high cholesterol, are normally denied coverage at the time of application or possibly not until when one has a serious health issue. In some locations, when joining IMSS, applicants pay the membership fee and then they are required to take a medical. If they are denied coverage at this point, the annual fee is not refunded. 

The first year’s coverage with IMSS is practically nil; the second year’s coverage is greater but full coverage is not until the third year. This is generally the health insurance one has when employed.