Overview
- The IMSS published the new agreement in the Diario Oficial de la Federación and the rules took effect on Thursday, October 22, 2026.
- New entrants must use their last registered salary as the base for voluntary contributions with a one-UMA uplift limit and a floor at the general minimum wage, retroactive incorporations are banned, enrollment must be digital, and Modalidad 10 cannot be held at the same time.
- People already enrolled in Modalidad 40 will keep their contracted conditions and the weeks and salaries they have paid will continue to count for pension calculations until their current period ends.
- President Claudia Sheinbaum publicly tied the change to alleged pension frauds and cited an impact of “cientos de miles de millones,” while the IMSS has six months to deliver a financial and actuarial analysis and the legal office may take up to six more months to draft proposals.
- Pension experts warn the limits close a loophole that let some Ley 73 workers raise their pension by choosing very high voluntary salaries (previously up to 25 UMAs), a change that could leave many retirees with substantially lower pensions and force revisions of retirement plans.