The Instituto Mexicano del Seguro Social is keeping Modalidad 40 open for people who have already stopped contributing and want to keep adding weeks toward retirement. The voluntary route, formally called Continuación Voluntaria en el Régimen Obligatorio, lets eligible former workers keep paying into the system on their own and work toward a larger future pension.
For many former workers, that is the point of the scheme: it preserves rights, keeps the retirement record active and includes coverage for Invalidez y Vida, as well as Cesantía en Edad Avanzada y Vejez. The IMSS says the arrangement is designed for people who have left formal employment but do not want their contribution history to stop there.
The timing matters because the option remains available in June 2026, and the requirements are already set. To register, a person must have been removed from the mandatory IMSS regime, have at least 52 weeks credited in the five years before the baja and submit the request within 12 months after the employment relationship ended. That window is narrow enough that anyone who waits too long can lose access altogether.
The application can be filed online or in person. Online, the applicant must enter the IMSS portal, choose the Continuación Voluntaria en el Régimen Obligatorio procedure, fill in personal data and pick the Salario Base de Cotización they want to use. The law gives the insured person that choice, but not without limits: the selected salary cannot be lower than the last salary recorded before the person left and cannot be higher than 25 times the current UMA.
That ceiling and floor are the part many people miss. A higher salary can mean larger contributions and, eventually, a better pension base, but the amount cannot be set arbitrarily. The monthly cost also is not fixed in advance because it depends on the chosen salary and the rates in force under the Ley del Seguro Social. The insured person must cover the full cost of the Invalidez y Vida insurance, along with the Retiro, Cesantía en Edad Avanzada y Vejez contributions.
Those who file online should receive a decision within five business days after sending the request. People who prefer to go in person must visit the subdelegación of the IMSS that corresponds to them and bring official identification, a free-form letter requesting registration to Modalidad 40 and proof of address no older than three months. If the request is approved, the IMSS issues the payment format needed to start the coverage.
The backdrop is the 2020 reform, which set gradual increases in contributions for the Cesantía en Edad Avanzada y Vejez branch through 2030. For people already out of the labor market, Modalidad 40 remains one of the few ways to keep contributing voluntarily while they try to improve the pension they will eventually receive.
