IMSS, ISSSTE and IMSS-Bienestar: Mexico’s Public Health System
Three public systems, three groups of people. How each one works in Mexico City, and the realistic route in for a foreign resident as of November 2026.
Mexico’s public health care runs through three main institutions. The Mexican Social Security Institute (IMSS) covers employees of private companies and their families, the Institute of Security and Social Services for State Workers (ISSSTE) covers federal government workers, and IMSS-Bienestar gives free care to people without social security. A foreign resident’s route depends on their job, not their passport.
How do IMSS, ISSSTE and IMSS-Bienestar differ?
| Institution | Who it covers | How you get in | Cost to the patient |
|---|---|---|---|
| IMSS | Private-sector employees, their registered family members, and people who sign up voluntarily | Employer registration, or voluntary enrollment | Funded by contributions from worker, employer and government; voluntary members pay an annual fee |
| ISSSTE | Employees of the federal government and their families | Through the government employer | Funded by payroll contributions |
| IMSS-Bienestar | People without social security | Registration at an IMSS-Bienestar module or clinic | Services and medicines free at the point of care |
Many people in Mexico City also pay for private doctors or carry private insurance on top of, or instead of, a public option. Our guide to private health insurance in Mexico explains how major medical policies work.
Can foreign residents use IMSS?
Yes, in two ways. If you work for a Mexican employer, the Social Security Law requires the employer to register you with IMSS, whatever your nationality, and you get a social security number (NSS) and access to IMSS clinics and hospitals. If you are self-employed, retired or work remotely for a foreign company, you can apply for IMSS voluntary health coverage, the family health insurance (Seguro de Salud para la Familia), which has an annual fee by age and waiting periods for some conditions.
Our step-by-step guide to IMSS voluntary enrollment for foreign residents covers documents and costs. You will need a CURP for almost any IMSS procedure.
Who uses ISSSTE?
ISSSTE serves people who work for the federal government, such as ministries and federal agencies, plus their registered relatives and its pensioners. Few foreign residents qualify, because the coverage comes only through a government job. A foreign resident married to a federal employee may be able to join as a dependent; ISSSTE decides who counts as a beneficiary.
What is IMSS-Bienestar and who can use it?
IMSS-Bienestar is the federal public system for people who have no social security. Article 77 bis 1 of the General Health Law says that all people in the country who lack social security have the right to free public health services, medicines and related supplies when they need care. That covers outpatient visits, hospital stays and surgery in the system’s units, with medicines from the national list of health supplies.
The system operates in the states that signed on to it, and Mexico City’s government signed the IMSS-Bienestar agreement in 2023. IMSS-Bienestar says its services are public, universal and free. To use them:
- Find a nearby unit or registration module with the locator on the IMSS-Bienestar website.
- Register in person at a module; IMSS-Bienestar issues a beneficiary credential. Bring an official ID, your CURP and proof of address, since clinics commonly ask for them.
- Go to your assigned health center for routine care; the center refers you to hospitals when needed.
IMSS-Bienestar’s phone line is 800 298 11 50, Monday to Friday from 9:00 to 15:00 and 17:00 to 19:00. The law gives the right to everyone in the country without social security, but units decide paperwork in practice, so a foreign resident should bring the resident card and CURP.
Which option makes sense for a foreign resident in Mexico City?
- Employed by a Mexican company: you are already in IMSS through payroll; ask HR for your NSS and your assigned family medicine unit (UMF).
- Retired or self-employed: IMSS voluntary coverage or private insurance, with IMSS-Bienestar available as a free public option.
- Married to a federal employee: ask about ISSSTE dependent coverage.
If you start a job, the employer registers you and you then pick up your IMSS number (NSS) and register at the family medicine unit (UMF) that corresponds to your home address. Keep the address on file current, because the UMF assignment follows it. If you leave the job, IMSS coverage continues only for a limited period, so plan the switch to voluntary coverage, private insurance or IMSS-Bienestar in advance.
Public systems can have long waits for specialists and scheduled surgery, which is why many residents combine public coverage with private care. In an emergency, call 911; our page on emergency numbers in Mexico City explains the options.
This article explains how the public system is organized and is not medical or legal advice. Each institution decides eligibility, and a doctor decides your care.
Bottom line
Work out which group you are in first: employee, government worker or neither. Get your CURP sorted, then register with IMSS through your employer or voluntarily, or with IMSS-Bienestar if you have no social security.
FAQ
Can I be in IMSS and use IMSS-Bienestar?
IMSS-Bienestar is for people without social security. If you have IMSS coverage, use IMSS units for your care.
Does a temporary resident qualify for IMSS voluntary coverage?
Temporary and permanent residents with a CURP can apply, subject to IMSS’s rules on preexisting conditions and waiting periods. IMSS has the final say on each application.
Are medicines free at IMSS?
IMSS members receive prescribed medicines from IMSS pharmacies at no extra charge, within IMSS’s list of medicines. Drugs outside that list are bought privately.