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IMSS calculator 2026: your social security deductions
Enter your gross monthly salary, years with the employer and minimum-wage zone to see your contribution base (SBC) and every IMSS deduction on your Mexican payslip.
Reviewed by Radif Partners · Editorial policy
Employee IMSS contribution per month
MX$400
SBC MX$524.66 a day · 2.67 % of gross
| Sickness and maternity, above 3 UMA (0.40%) | MX$21.00 |
|---|---|
| Cash benefits (0.25%) | MX$39.87 |
| Pensioners’ medical costs (0.375%) | MX$59.81 |
| Disability and life (0.625%) | MX$99.68 |
| Old-age and severance-at-old-age (1.125%) | MX$179.43 |
| Monthly total (30.4 days) | MX$400 |
| Integration factor | 1.0493 |
IMSS (Instituto Mexicano del Seguro Social) is Mexico’s social security institute, and every employee on a Mexican payroll pays a share of its contributions, withheld by the employer. The share is not charged on your salary as such but on your contribution base, the SBC (salario base de cotización): your daily wage, monthly pay divided by 30, multiplied by an integration factor that spreads the aguinaldo and vacation premium across the year, 1.0493 in the first year. On that base you pay 2.375 % across four branches, plus 0.4 % on the part of the SBC above 3 UMA (MX$351.93 a day). The UMA, Unidad de Medida y Actualización, is the official reference unit that replaced the minimum wage in laws. On MX$40,000 a month the SBC is MX$1,399.09 and IMSS takes MX$1,137.47. The base is capped at 25 UMA, MX$2,932.75 a day in 2026.
Annual IMSS cost at common professional salaries
| Gross monthly | Integration factor | Daily SBC | IMSS per month | IMSS per year | Note |
|---|---|---|---|---|---|
| MX$30,000 | 1.0493 | MX$1,049.32 | MX$842 | MX$10,109 | |
| MX$40,000 | 1.0493 | MX$1,399.09 | MX$1,137 | MX$13,650 | |
| MX$60,000 | 1.0493 | MX$2,098.63 | MX$1,728 | MX$20,731 | |
| MX$80,000 | 1.0493 | MX$2,798.17 | MX$2,318 | MX$27,813 | |
| MX$150,000 | 1.0493 | MX$2,932.75 | MX$2,431 | MX$29,175 | Capped |
Mid-career expatriate salaries sit well inside the contribution band, so IMSS takes a near-constant slice of about 2.84 % of gross. Only executive packages reach the cap. Compared with social security in much of Europe or North America, the employee share is small.
Where your MX$40,000 deduction goes
- Old-age and severance-at-old-age (cesantía y vejez), 1.125 %: MX$478.49, paid into your personal Afore retirement account.
- Disability and life insurance, 0.625 %: MX$265.83.
- Sickness and maternity above 3 UMA, 0.4 % of the excess: MX$127.33.
- Pensioners’ medical costs, 0.375 %: MX$159.50.
- Cash sickness and maternity benefits, 0.25 %: MX$106.33.
If you leave Mexico, the Afore balance stays yours. Withdrawal rules depend on age and contribution weeks, so check them with your Afore before you go.
The integration factor and your seniority
The factor grows with time because Mexican vacation entitlement grows: 12 days in the first year, then more with each anniversary, as the vacation days page explains. More vacation days mean a larger vacation premium inside the SBC. If your contract grants more than the statutory 15-day aguinaldo or a higher premium, your real SBC is higher than this estimate. Your employer reports it to IMSS, and you can ask for it.
Floor and minimum-wage rule
The SBC can never be lower than the minimum wage of your zone, MX$315.04 a day in most of the country in 2026. Employees earning only that minimum, about MX$9,582 a month, have nothing withheld: article 36 of the Social Security Law makes the employer pay their share. For your full take-home figure after IMSS and income tax, use the net salary calculator, or the ISR tax calculator for the tax side alone.
Frequently asked questions
I am a foreign national on a Mexican payroll. Do I have to pay IMSS?
Yes. Registration with IMSS, the Mexican Social Security Institute, follows the employment relationship, not your passport or visa. Once a Mexican employer hires you, it must enrol you and withhold the employee share each payday. On MX$40,000 a month that share is about MX$1,137. In return you get public healthcare, paid sick leave and a retirement account (Afore) in your name.
What does SBC mean on my Mexican payslip?
Salario base de cotización, the daily wage on which IMSS contributions are charged. It is your monthly salary divided by 30 (article 29 of the Social Security Law), multiplied by an integration factor that adds the aguinaldo and vacation premium, 1.0493 in your first year with statutory benefits. Your SBC also feeds the calculation of sick pay and pensions.
Why is IMSS almost the same on MX$150,000 as on MX$300,000 a month?
Because article 28 of the Social Security Law caps the SBC at 25 times the daily UMA, MX$2,932.75 in 2026. Above roughly MX$83,848 of monthly salary in the first year, extra pay adds nothing. Both salaries sit above that line, so the employee share is identical, about MX$2,431 a month, even though one salary is double the other.
Is IMSS deducted from my pay before ISR is worked out?
No. Income tax (ISR) is charged on gross taxable pay and the IMSS employee share is withheld separately, so neither reduces the other. On MX$40,000 a month you see two lines: ISR from the Annex 8 tariff and IMSS of MX$1,137. The net salary calculator combines both to show what actually reaches your bank account each month.
Does this calculator show what my employer pays to IMSS?
No, on purpose. Employer contributions are several times the employee share, and the old-age branch follows a transitional schedule that rises every year. We have not verified the 2026 employer rates against an official source, so we publish none. If you are budgeting a hire or comparing an offer, ask the employer for its payroll cost or consult a Mexican payroll provider.
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Written by Radif Partners
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Rates 2026, checked on