October 23, 2026
On October 21, 2026, Resolution ACDO.AS2.HCT.101026/302.P.DG was published in the Official Gazette of the Federation (Diario Oficial de la Federación). The Resolution was adopted by the Technical Council of the Mexican Social Security Institute (“IMSS”) at an extraordinary session held on October 10, 2026, and directs that an analysis be conducted on the financial impact of the Voluntary Continuation in the Mandatory Social Security Regime (Continuación Voluntaria en el Régimen Obligatorio), commonly known in Mexico as “Modalidad 40”, while establishing various temporary measures for its operation.
The Technical Council instructed the IMSS Directorate of Finance, through the Financial and Actuarial Risks Unit and with information provided by the Institute’s relevant areas, to conduct, within a maximum period of six months, an analysis of the impact of the Voluntary Continuation on IMSS’s financial position.
Based on the results of such analysis, the Legal Directorate will have an additional period of up to six months to coordinate, as applicable, the preparation of a proposal to amend the relevant regulatory provisions, with the aim of ensuring the viability of this modality in the medium and long term.
In the meantime, individuals who are already enrolled in the Voluntary Continuation as of the effective date of the Resolution may remain enrolled under the current conditions until the end of their contracted period.
By contrast, individuals who complete such period and wish to continue, as well as those who subsequently apply to enroll in Modality 40 in order to preserve their social security rights for pension purposes, may do so based on the last contribution base salary registered at the time they ceased to be covered under the mandatory regime, with the option to select a salary of up to that amount plus one Unit of Measurement and Update (Unidad de Medida y Actualización, UMA). In no event may the salary be lower than the general minimum wage in effect for the rest of the country.
This measure represents a significant restriction compared to the conditions previously applicable, under which insured individuals could elect to continue contributing based on their last contribution base salary or a higher salary, without exceeding the limit of 25 UMA. Its effect may be particularly relevant for individuals entitled to a pension under the regime of the 1973 Social Security Law, under which the average salary corresponding to the last 250 weeks of contributions is one of the elements used to determine the amount of the pension.
Likewise, new enrollments under this modality will take effect exclusively as of the date on which the corresponding application is filed and will have no effect for prior periods.
The Resolution also recognizes the possibility for individuals to voluntarily enroll in the mandatory social security regime as independent workers. However, individuals enrolled as independent workers under Article 13, Section I, of the Social Security Law may not simultaneously enroll in the Voluntary Continuation in the Mandatory Social Security Regime.
Additionally, IMSS will make the necessary adjustments to its processes and systems so that enrollment in the Voluntary Continuation is carried out exclusively through digital mechanisms, without prejudice to establishing an assistance channel for the review of special cases related to the implementation of the Resolution.
It is important to note that individuals who are enrolled in the Voluntary Continuation as of the effective date of the Resolution will retain recognition of the contribution weeks and contribution base salaries corresponding to contributions actually paid, which will continue to have full effect for purposes of calculating their future pension entitlements.
Therefore, the published measures do not yet constitute a definitive modification to the Modality 40 regime. Rather, they are temporary rules applicable while IMSS evaluates the financial impact of Modality 40 and, as applicable, prepares a proposal to amend the relevant regulatory framework.
The Resolution entered into force today, October 22, 2026, the business day following its publication in the Official Gazette of the Federation.
Our Social Security team remains available to provide advice regarding the application of these temporary measures and their potential implications for pension matters.
SINCERELY,
Gil Zenteno
Gabriela Méndez
Jesús Carmona