Overview
- The IMSS published new rules that took effect on 22 October 2026 that stop retroactive contracts in Modalidad 40 and set limits on declared cotization.
- New entrants must have enrollment take effect from their application date and may only cotize at their last registered salary or that salary plus one UMA.
- IMSS says the measures respond to an industry of advisers and lenders that lent money for five‑year retroactive purchases and produced large pension inflation in some cases.
- Pension specialists say Modalidad 40 remains an option for people who left formal employment but will generally yield lower pensions and less flexibility than before; transfers from Modalidad 10 to 40 are now restricted.
- The IMSS will carry out a financial analysis of Modalidad 40 over the coming months and may propose further regulatory changes within about a year, a process that could alter eligibility and costs for future retirees.