Countries › Mexico › Guide › 7. Labor and employment › Social security in Mexico (IMSS and INFONAVIT): who must be registered, the five day deadline, what workers receive and what employers risk

Social security in Mexico (IMSS and INFONAVIT): who must be registered, the five day deadline, what workers receive and what employers risk

Last verified: 2026-10-26 · Status: Changing

Every employer must register with the Mexican Social Security Institute (IMSS) and enroll each worker, report hires, exits and salary changes within five business days, keep payroll records for five years and pay contributions monthly; the same workers are covered by the INFONAVIT housing fund at 5 percent of salary. Insured workers receive medical care and cash benefits from IMSS: 60 percent of salary for non work illness from the fourth day, 100 percent for work injuries and for 84 days of maternity leave, plus old age and severance pensions from ages 65 and 60 that require 875 weeks of contributions in 2026, rising to 1,000 in 2031. An employer that has not registered a worker when an accident happens must reimburse IMSS the full cost of the benefits, and late registration is fined; contribution rates are covered on the payroll taxes page.

USD conversions use MXN 18.5026 per US dollar, the US Federal Reserve H.10 noon buying rate in New York for 16 October 2026 (FRED series DEXMXUS), the latest observation available when this page was verified. Conversions are for orientation only.

Key facts

Deadline to register hires, exits and salary changes with IMSS	5 business daysLSS art. 15, section I, as of 2026-10-26 · in force
Payroll record retention	5 yearsLSS art. 15, section II, as of 2026-10-26 · in force
IMSS cash benefit for non work illness (from day 4)	60 % of contribution salaryLSS arts. 96 and 98, as of 2026-10-26 · in force
IMSS cash benefit for temporary work injury	100 % of contribution salaryLSS art. 58, section I, as of 2026-10-26 · in force
IMSS paid maternity benefit	84 daysLSS art. 101, as of 2026-10-26 · in force
Weeks of contributions required for old age and cesantía pensions, 2026	875 weeksLSS arts. 154 and 162; decree DOF 16 December 2020, transitional art. Cuarto, as of 2026-10-26 · in force
Weeks of contributions required from 2031	1000 weeksLSS arts. 154 and 162, as of 2026-10-26 · pending
Old age pension age	65 yearsLSS art. 162, as of 2026-10-26 · in force
INFONAVIT employer contribution	5 % of salaryLey del INFONAVIT art. 29, section II, as of 2026-10-26 · in force

The rule

1. Who is covered. The mandatory regime covers every person who provides personal, subordinated and paid work for another under LFT arts. 20 and 21, permanent or temporary, whatever the legal form of the employer and even if the employer is exempt from taxes; members of cooperatives; domestic workers; and others designated by presidential decree.Ley del Seguro Social (LSS), DOF 21 December 1995 (Chamber of Deputies consolidated text, last reform DOF 15 January 2026), Art. 12, 2019-07-02 official text · verified 2026-10-26

2. Employer obligations. Employers must register themselves and enroll their workers with IMSS, and report hires, exits, salary changes and other data within five business days; keep payroll records showing days worked and salaries, and retain them for five years; determine and pay worker and employer contributions; provide IMSS with the information it requests and allow its inspections; and meet the retirement, old age and severance obligations.
Cost to do it: IMSS and INFONAVIT registration carry no government fee; the cost is the monthly contributions (see taxes/payroll-taxes).Ley del Seguro Social (LSS), DOF 21 December 1995 (Chamber of Deputies consolidated text, last reform DOF 15 January 2026), Art. 15, 2024-01-24 official text · verified 2026-10-26

3. Housing fund. Employers must register their workers with INFONAVIT, pay 5 percent of each worker's salary into the housing subaccount, and withhold and pay workers' INFONAVIT loan repayments.
Cost to do it: 5 percent of salary, subject to the contribution salary cap.
Example: At a contribution salary of MXN 800 a day the employer pays MXN 1,216.00 for a 30.4 day month. / About USD 65.72.Ley del INFONAVIT, DOF 24 April 1972 (Chamber of Deputies consolidated text, last reform DOF 21 February 2025), Art. 29, sections I, II and III, 1997-01-06 official text · verified 2026-10-26

4. Sickness and maternity benefits. For a non work illness that prevents working, IMSS pays a cash benefit of 60 percent of the last daily contribution salary from the fourth day of incapacity for up to 52 weeks, extendable by 26 weeks. For maternity, IMSS pays 100 percent of the last daily contribution salary for 42 days before and 42 days after birth if the worker has at least 30 weekly contributions in the previous 12 months; otherwise the employer pays the full salary.
Example: A worker with a contribution salary of MXN 800 a day off sick for 10 days receives MXN 480.00 a day from IMSS for days 4 to 10 (MXN 3,360.00); a mother with the same salary receives MXN 67,200.00 for 84 days of maternity leave. / About USD 182 and USD 3,632 at 18.5026.Ley del Seguro Social (LSS), DOF 21 December 1995 (Chamber of Deputies consolidated text, last reform DOF 15 January 2026), Arts. 96, 98, 101, 102 and 103, 2023-03-24 official text · verified 2026-10-26

5. Work risks. A worker temporarily disabled by a work accident or occupational disease receives 100 percent of the contribution salary at the time of the risk until declared fit or permanently disabled. If the employer had not insured the worker against work risks when the accident occurred, or had reported a lower salary, it must pay IMSS the capital needed to fund the benefits in cash and in kind (capitales constitutivos), and hire notices or salary changes filed after the accident never release it, even if filed within the five day deadline.
Cost to do it: The full actuarial cost of the injured worker's medical care, subsidies and any pension if the worker was not registered or was under reported.Ley del Seguro Social (LSS), DOF 21 December 1995 (Chamber of Deputies consolidated text, last reform DOF 15 January 2026), Arts. 58, section I, and 77, 2001-12-20 official text · verified 2026-10-26

6. Old age and severance at advanced age. Severance at advanced age (cesantía) applies from age 60 and the old age pension from 65; both require 1,000 weekly contributions. Under the December 2020 reform the requirement started at 750 weeks on 1 January 2021 and rises by 25 weeks a year until it reaches 1,000 in 2031, so it is 875 weeks in 2026. Insured workers who reach the age without the weeks may withdraw their account balance or keep contributing, and with at least 750 weeks keep medical benefits.Decree amending the LSS (pension reform), DOF 16 December 2020, in force 1 January 2021; Ley del Seguro Social (LSS), DOF 21 December 1995 (Chamber of Deputies consolidated text, last reform DOF 15 January 2026), LSS arts. 154 and 162; decree transitional arts. Primero and Cuarto, 2020-12-16 official text · verified 2026-10-26 · changed: Decree of DOF 16 December 2020 set the weeks required at 750 in 2021, rising 25 a year to 1,000 in 2031, and raised employer old age contributions from 2023 to 2030.

7. Fines. Failing to register with IMSS or to enroll workers, or doing so late, is fined 20 to 350 UMA; failing to file or filing late the specialized services contract reports required by LSS art. 15 A is fined 500 to 2,000 UMA. No fines apply when obligations are met spontaneously before IMSS discovers the omission or serves an audit order or request.
Cost to do it: MXN 2,346.20 to MXN 41,058.50 for late registration; MXN 58,655.00 to MXN 234,620.00 for missing specialized services reports, at the 2026 UMA of MXN 117.31.
Example: MXN 2,346.20 to MXN 41,058.50. / About USD 127 to USD 2,219.Ley del Seguro Social (LSS), DOF 21 December 1995 (Chamber of Deputies consolidated text, last reform DOF 15 January 2026), Arts. 304 A, sections I, II and XXII, 304 B, sections IV and V, and 304 C, 2021-04-23 official text · verified 2026-10-26

Year	Weeks required
2021	750
2022	775
2023	800
2024	825
2025	850
2026	875
2027	900
2028	925
2029	950
2030	975
2031	1000

Weeks of contributions required for old age and cesantía pensions (LSS arts. 154 and 162; decree DOF 16 December 2020, transitional art. Cuarto).

Worked example

A new subsidiary hires 20 workers on 3 March. It must have its IMSS employer registration and enroll all 20 within five business days, and report each later salary change in the same period.
One worker is injured on the second day, before enrollment was filed. IMSS treats the worker, but because the worker was not insured when the accident happened the company must reimburse IMSS the capital needed for all benefits, even though its deadline had not expired (LSS art. 77).
Late enrollment of the other workers can be fined 20 to 350 UMA (MXN 2,346.20 to MXN 41,058.50, about USD 127 to USD 2,219), unless the company corrects it spontaneously before IMSS acts.
Enrolling every worker on day one avoids both risks.

Step by step

1. Obtain the employer registration with IMSS (and the corresponding INFONAVIT registration) before the first hire.
2. Enroll each worker on or before the first working day; the law allows five business days, but an accident before enrollment leaves the company liable for the full cost of benefits (LSS art. 77).
3. Report every salary change and exit within five business days and keep payroll records for five years.
4. Calculate and pay IMSS, retirement and INFONAVIT contributions monthly (see taxes/payroll-taxes for the rates and the 17th of the month deadline).
5. Track each worker's IMSS incapacity certificates and adjust payroll so the company does not pay salary for days covered by IMSS benefits.

Common traps

Registering after the first week. Hire notices filed after an accident never release the employer from capitales constitutivos (LSS art. 77).
Under reporting the contribution salary. Benefits are paid on the reported salary; the employer pays the gap if it reported less than the real integrated salary.
Assuming the employee is covered for maternity. Without 30 weekly contributions in the last 12 months, the employer pays the full salary for the leave (LSS art. 103).
Ignoring specialized services reports. Contractors registered in REPSE must report their contracts to IMSS every four months (LSS art. 15 A).

Sources

← Employee profit sharing (PTU) in Mexico: 10 percent of taxable income, how it is split, the three month cap, deadlines and exemptionsDismissal and severance in Mexico: just causes, the written notice rule, three months plus 20 days a year, seniority premium, back wages and collective terminations →