IMSS Caps Modalidad 40 Salaries and Bars Retroactive Registrations

Overview

• The IMSS published the new agreement in the Diario Oficial de la Federación on October 21 and the rules took effect on October 22, 2026.
• Under the new rules new applicants may register only with their last reported base salary or that amount plus one UMA and never below the general minimum wage, and retroactive high-salary enrollments are no longer allowed.
• The agreement requires digital adjustments to enrollment, prevents certain independent-worker schemes from using Modalidad 40 at the same time, and preserves weeks and paid salaries for people already enrolled.
• The IMSS Council ordered a six-month financial and actuarial study by its Unidad de Riesgos Financieros y Actuariales followed by up to six months for the Dirección Jurídica to draft any permanent legal changes, so the measures are presented as temporary.
• Experts warn the limits will reduce the ability of many workers—especially those under the pre-1997 Ley 73—to boost future pensions, and the president’s claim of “hundreds of thousands of millions” in fraud lacks the public evidence that would clarify the fiscal case for lasting reform.