IMSS employer contributions: what a first hire costs a company in Mexico

A foreign company that hires its first employee in Mexico often budgets the salary and nothing else. On top of pay come IMSS contributions for five insurance branches, INFONAVIT housing contributions and a state payroll tax, each with its own base and rate. The real cost per hire is higher than the offer letter, and from 2027 the gradual cut to a 40-hour workweek adds another variable to the cost of each hour worked.

At Soulbit Academy we treat this guide as the Mexican counterpart of our guide to PILA contributions for Colombian employers. It explains what IMSS employer contributions include, how the contribution salary base works, which cap applies in 2026 and what one employee costs in a worked example with assumed numbers. It does not replace your accountant.

What IMSS employer contributions are and who pays them

IMSS employer contributions, known in Mexico as cuotas obrero patronales, are the payments that employer and employee make to the Mexican Social Security Institute for each insured worker. Article 39 of the Social Security Law says they accrue in monthly installments and that the employer must determine them even if it does not pay on time.

The employer pays its share, withholds the employee share from salary and remits both. The compulsory regime covers work risks, illness and maternity, disability and life, retirement with severance and old age, and daycare with social benefits.

The duty applies to anyone who provides personal subordinate service, whatever their nationality. The border with the independent contractor is the biggest risk, covered in contractor vs. employee: how to pay each legally in LATAM.

How the contribution salary base and the integration factor work

The contribution salary base (SBC, from the Spanish salario base de cotización) is the daily salary integrated with the benefits the worker receives, with a floor of one minimum wage and a ceiling of 25 times the reference unit. Article 27 of the Social Security Law builds it from daily pay, bonuses, commissions, premiums and any other amount delivered for the work.

The law excludes, among others, work tools, savings that meet certain conditions, the employer's own contributions, INFONAVIT contributions and profit sharing. That is why profit sharing does not raise the SBC, a topic we develop in profit sharing (PTU) in Mexico: an employer guide.

The integration factor turns daily pay into SBC. With the minimums of the Federal Labor Law, that is 15 days of year-end bonus (article 87), 12 vacation days after one year of service (article 76) and a 25% vacation premium (article 80), the factor is (365 + 15 + 3) / 365 = 1.0493. This is an assumption: many employers grant more and their factor is higher.

Does everything an employee receives count toward the contribution salary base?

No. What is delivered for the work counts, such as bonuses, commissions and benefits in kind, and the items listed in article 27 are excluded, such as INFONAVIT contributions and profit sharing. Variable income is averaged by two-month period, and the employer must notify the IMSS of changes in the average daily salary in the first five business days of January, March, May, July, September and November, under article 34.

What the employer pays per insurance branch in 2026

The employer pays a fixed quota on the UMA, a surplus on the part of the SBC above three UMA and flat percentages on the full SBC. The 2026 UMA is 117.31 pesos a day, per the DOF of January 9, 2026 as published by INEGI, in force since February 1, 2026.

The rates for illness and maternity, disability and life, daycare and retirement come from articles 25, 107, 147, 168 and 211 of the Social Security Law. The fixed quota of 20.40% of the UMA and the surplus of 1.10% employer and 0.40% employee follow from article 106 and its nineteenth transitory provision, which moved the original rates until 2007. The institute reproduces them in its SUA guide.

Work risks is the only branch the employer pays in full, and it has no flat rate. The premium follows the company's claims record and the law bounds it between 0.5% and 15% of the SBC in articles 72 to 74.

Branch	Base	Employer	Employee
Work risks	SBC	Company premium (0.5% to 15%)	0%
Illness and maternity, fixed quota	Daily UMA	20.40% of the UMA	0%
Illness and maternity, surplus	SBC minus 3 UMA	1.10%	0.40%
Cash benefits	SBC	0.70%	0.25%
Medical expenses of pensioners	SBC	1.05%	0.375%
Disability and life	SBC	1.75%	0.625%
Daycare and social benefits	SBC	1%	0%
Retirement	SBC	2%	0%
Severance in old age and old age (CEAV)	SBC	3.150% to 7.513% by range	1.125%

Severance in old age and old age (CEAV) is the branch that changed most. The pension reform published in the DOF on December 16, 2020 raises the employer rate gradually from 2023 to 2030 and ties it to the salary range. Per the official summary of the decree, the 2026 employer rate is 3.150% for one minimum wage, 3.676% from 1.01 minimum wages to 1.50 UMA, 4.851% from 1.51 to 2.00 UMA, 5.556% from 2.01 to 2.50 UMA, 6.026% from 2.51 to 3.00 UMA, 6.361% from 3.01 to 3.50 UMA, 6.613% from 3.51 to 4.00 UMA and 7.513% from 4.01 UMA up. The employee rate stays at 1.125%.

INFONAVIT, payment schedule and IMSS filings

The employer must contribute 5% of the worker's salary to INFONAVIT, for the housing subaccount, under article 29, section II, of the INFONAVIT Law. It is an employer cost that is not deducted from the worker and it is calculated on the same base with the 25 UMA cap.

Payment runs at two rhythms. Article 39 of the Social Security Law sets payment of contributions no later than the 17th of the following month, and the SUA produces in even months the form that includes retirement, CEAV and INFONAVIT for the two-month period. Confirm the current year's deadlines with the IMSS.

Two IMSS tools support compliance. The SUA (Sistema Único de Autodeterminación) calculates contributions and produces the payment form. The IDSE (IMSS Desde Su Empresa) files hires, terminations and salary changes for each worker. A late notice or an understated salary creates differences the IMSS can collect with adjustments and surcharges.

The state payroll tax (ISN) is a separate cost. Each state collects it, rates and rules differ by state and it is not part of IMSS contributions. Check the rate of the state where the establishment sits before hiring.

Worked example: what one employee earning 45,000 pesos a month costs

An employee paid 45,000 pesos a month generates employer contributions and INFONAVIT of about 23.5% of salary, that is 10,571.16 pesos a month in this example. The figures are calculation assumptions, not Soulbit prices or data from a real company.

The assumptions are a 45,000 peso monthly salary, a 30-day month, a daily salary of 1,500 pesos, an integration factor of 1.0493 with statutory minimum benefits, a UMA of 117.31 pesos and a work-risk premium of 1% chosen only for the example.

The SBC is 1,500 × 1.0493 = 1,573.97 pesos a day. It sits below the cap of 2,932.75 pesos a day (25 × 117.31) and equals 13.42 UMA, so CEAV uses the 7.513% rate. The surplus is computed on 1,573.97 minus 351.93 (3 UMA), that is 1,222.04 pesos a day.

Employer item	Daily calculation	Monthly (30 days)
Work risks (assumed 1%)	1% of 1,573.97	472.19
Illness and maternity, fixed quota	20.40% of 117.31	717.94
Illness and maternity, surplus	1.10% of 1,222.04	403.27
Cash benefits	0.70% of 1,573.97	330.53
Medical expenses of pensioners	1.05% of 1,573.97	495.80
Disability and life	1.75% of 1,573.97	826.33
Daycare and social benefits	1% of 1,573.97	472.19
Retirement	2% of 1,573.97	944.38
Severance in old age and old age	7.513% of 1,573.97	3,547.57
IMSS subtotal		8,210.20
INFONAVIT	5% of 1,573.97	2,360.96
Total employer contributions		10,571.16

Under those assumptions the monthly cost to the employer is 45,000 + 10,571.16 = 55,571.16 pesos, before state payroll tax, the accrual for the year-end bonus and vacation, and profit sharing. The employee share, withheld from pay, adds 1,268.10 pesos. CEAV alone is 3,547.57 pesos, which is why the pension reform is the largest driver of payroll cost between 2023 and 2030.

The 2026 general minimum wage is 315.04 pesos a day, per the CONASAMI publication of the DOF resolution of December 9, 2025, in force since January 1, 2026.

What changes when you pay in dollars or hire a foreign national

The SBC is always expressed in pesos, because the IMSS collects in pesos and the caps and the UMA are in pesos. Paying in dollars does not remove the obligation: daily salary, factor and contributions depend on the peso amount the contract fixes.

Can a company pay a Mexican employee's salary in dollars?

Article 101 of the Federal Labor Law requires cash wages to be paid in legal tender and allows bank deposit or electronic means with the worker's consent. The contract should therefore set the salary in pesos, and any scheme paying in another currency or a digital asset must be validated with a labor adviser first. The exchange rate between a peso contract and the company's dollar funds is a treasury risk, not a social security matter.

A foreign national working under subordination in Mexico is insured like a Mexican employee. For a company abroad without a Mexican entity, the usual routes are a subsidiary with an employer registration or an employer-of-record arrangement, not paying as a contractor someone who is in fact an employee. The remote-worker case is in payroll for remote workers in Mexico and CFDI. Each pay slip also requires the payroll CFDI.

What Soulbit does in Mexican payroll and what it does not

Soulbit Salaries disburses payroll in batches in stablecoin: the employer uploads the file with net payments and the platform executes them from a USDC or USDT balance under institutional custody. The flow is explained in batch payroll: from file to disbursement.

Soulbit does not calculate the contribution salary base, does not determine IMSS contributions, does not file the SUA or the IDSE and does not issue the payroll CFDI. It also has no local bank rail in Mexico today: the product's only local rail is Colombia. All labor and tax calculations stay with the employer or its accountant, and responsibility to the IMSS, INFONAVIT and the SAT does not transfer to a payment tool.