Mexico Statutory social-insurance contributions

What this value means

WHAT A PAYROLL ENGINE GETS WRONG IN MEXICO. 1. Two consolidated-text traps in art. 106 (sickness & maternity, benefits in kind). The current consolidated LSS still prints 13.9% for the flat employer quota (fr. I) and 6%/2% for the additional quota over 3 UMA (fr. II). Those figures have been wrong since 2007. The operative figures are 20.4% and 1.1%/0.4%, produced by the Artículo Décimo Noveno Transitorio of the 1995 law, which moved them by fixed steps each 1 July from 1998 to 2007. Anyone reading only the statute understates employer cost on the flat quota by a third and overstates the excedente by more than five times. 2. A third consolidated-text trap in art. 168 fr. II a) (cesantía y vejez). The table printed in the statute (3.150% to 11.875%) is the 2030 end-state, not today's law. The rates in force are the year column of the ARTÍCULO SEGUNDO TRANSITORIO of the DOF 16-12-2020 pension decree. For 2026 the top bracket is 7.513%, not 11.875%. 3. The flat sickness/maternity quota is not a percentage of salary. Art. 106 fr. I charges 20.4% of one UMA per insured worker per day (MXN 23.93/day at the 2026 UMA), independent of what the worker earns. Modelling it as a percentage of pay is wrong at both ends of the wage distribution. 4. Ceiling vs threshold. There is one contribution ceiling — 25 UMA of daily SBC (art. 28) — and it applies to every branch. Separately there is a 3-UMA THRESHOLD in art. 106 fr. II: below it nothing is due on that sub-branch, above it only the excess is charged, and that excess is itself capped by the 25-UMA ceiling (max slice 22 UMA/day). They are different instruments doing different jobs; conflating them is the classic Mexican error. 5. The statute says "salario mínimo", the law means UMA. Art. 28 still reads "veinticinco veces el salario mínimo general que rija en el Distrito Federal". Under the Artículo Tercero Transitorio of the constitutional desindexación decree (DOF 27-01-2016), every reference to the minimum wage used as an index or measure is read as UMA. So the ceiling is 25 UMA (MXN 2,932.75/day), not 25 minimum wages (which would be MXN 7,876/day). The FLOOR is the opposite case: art. 28's lower limit is a real minimum wage, not an index, so it stays the actual general minimum wage of the geographic area. 6. The cesantía y vejez bracket table mixes units, and the mix does not close. Row 1 is "1.00 SM" (a minimum wage), rows 2 to 8 are UMA multiples, and row 2 is literally "1.01 SM a 1.50 UMA". At 2026 values 1.01 SM = MXN 318.19/day = 2.71 UMA, which is far above 1.50 UMA = MXN 175.97 — so read literally that band has no arithmetic domain, and a minimum-wage worker would fall in the 2.51–3.00 UMA row. The only coherent operative reading, and the one every published IMSS table uses, is: row 1 applies when the SBC equals exactly the general minimum wage (employer 3.150%), and rows 2–8 are applied on SBC expressed in UMA. We flag this as a defect in the instrument rather than claim it has been officially resolved. 7. Minimum-wage workers pay nothing. LSS art. 36: where the worker's daily wage is the minimum wage, the employer pays the worker's quotas in full. Net pay is therefore gross for those workers, and the employer picks up the whole 2.375% (or 2.775%) worker side. 8. Employee contributions are NOT deductible before income tax. ISR withholding under LISR art. 96 is computed on "la totalidad de los ingresos obtenidos en un mes"; the only thing subtracted is a state salary tax up to 5%. IMSS worker quotas do not reduce the withholding base and are not in the closed list of deducciones personales in LISR art. 151. Getting this wrong inflates net pay. The mirror rule: if the employer absorbs the worker's quota (art. 36 or voluntarily), that amount is exempt income for the worker (LISR art. 93 fr. XII) but is NOT deductible for the employer (LISR art. 28 fr. I), whereas the employer's own quotas are deductible (LISR art. 25 fr. VI). 9. Employer totals. On SBC alone, for a worker at or above 4.01 UMA in 2026, the employer pays 20.113% (1.1 + 0.70 + 1.05 + 1.75 + 1.00 + 2.00 + 7.513 + 5.00), PLUS the riesgos de trabajo prima (0.5%–15%, employer-specific), PLUS the flat MXN 23.93/day sickness quota, PLUS state payroll tax. The worker pays 2.375% up to 3 UMA and 2.775% above it. Any "Mexico employer burden is about 30%" figure is a blend, not a rate. 10. Liability does not depend on nationality or residence. LSS art. 12 fr. I covers anyone in a subordinate remunerated relationship under LFT arts. 20–21, whatever the employer's legal form; there is no nationals-only carve-out and no expatriate exemption absent a totalisation agreement. Domestic workers were brought into the compulsory regime by DOF 02-07-2019 (art. 12 fr. IV). No rate varies by employee age or category in the compulsory regime for ordinary employees; the only category-dependent rate is the employer's cesantía y vejez bracket, which varies with the individual worker's own SBC. 11. Payment rhythm differs by branch. IMSS quotas are monthly, by the 17th of the following month (LSS art. 39). Retiro, cesantía y vejez remain BIMONTHLY (LSS Artículo Vigésimo Séptimo Transitorio). INFONAVIT art. 35 has said monthly since the DOF 06-01-2016 reform, and the two institutions may issue a joint liquidation. Cash-flow models keyed to a single cadence will be wrong. SCOPE EXCLUSIONS. Figures are for an ordinary private-sector employee in the régimen obligatorio. Not covered: ISSSTE (federal public servants), ISSFAM (armed forces), state-level public-worker schemes, cooperative members, the voluntary régimen (LSS art. 13, including independent workers), the Seguro de Salud para la Familia (voluntary, age-banded, art. 242), and the reversión de cuotas arrangements of art. 213. The LSS text as amended to DOF 15-01-2026 contains no separate contribution scheme for digital-platform workers. SUB-NATIONAL VARIATION: Contribution RATES are uniform nationwide — all 32 federative entities. There is no regional variation in any IMSS percentage or in the INFONAVIT 5%. Two things do vary geographically: 1. THE SBC FLOOR (LSS art. 28: lower limit = the general minimum wage of the respective geographic area). CONASAMI's resolution (DOF 09-12-2025, in force 1 Jan 2026) creates two zones: - Zona Libre de la Frontera Norte (ZLFN): MXN 440.87/day (MXN 13,409.80/month on CONASAMI's own 365/12 basis). It is a list of MUNICIPALITIES, not whole states: Ensenada, Playas de Rosarito, Mexicali, Tecate, Tijuana, San Quintín, San Felipe (MX-BCN); San Luis Río Colorado, Puerto Peñasco, General Plutarco Elías Calles, Caborca, Altar, Sáric, Nogales, Santa Cruz, Cananea, Naco, Agua Prieta (MX-SON); Janos, Ascensión, Juárez, Práxedis G. Guerrero, Guadalupe, Coyame del Sotol, Ojinaga, Manuel Benavides (MX-CHH); Ocampo, Acuña, Zaragoza, Jiménez, Piedras Negras, Nava, Guerrero, Hidalgo (MX-COA); Anáhuac (MX-NLE); Nuevo Laredo, Guerrero, Mier, Miguel Alemán, Camargo, Gustavo Díaz Ordaz, Reynosa, Río Bravo, Valle Hermoso, Matamoros (MX-TAM). - Zona del Salario Mínimo General (rest of the country, including all of Mexico City): MXN 315.04/day (MXN 9,582.47/month). An engine keyed to state codes alone will get the border zone wrong; it must be keyed to municipality within MX-BCN, MX-SON, MX-CHH, MX-COA, MX-NLE and MX-TAM. 2. CONSEQUENTLY, THE "1.00 SM" CESANTÍA Y VEJEZ BAND. Because the band is expressed in minimum wages while the others are in UMA, the zone changes which workers get the 3.150% employer rate. In the general zone a minimum-wage worker sits at 2.686 UMA (315.04 / 117.31); in the ZLFN at 3.758 UMA (440.87 / 117.31). Without the special band they would fall into the 6.026% and 6.613% rows respectively. 3. IMPUESTO SOBRE NÓMINAS is state-set in all 32 entities and differs everywhere; see the scheme record. No values published here. WHAT WE DO NOT PUT A NUMBER ON: No number given for RIESGOS DE TRABAJO. There is no national rate: LSS arts. 72 and 74 make the prima employer-specific, derived from that employer's own accident experience and re-declared annually, moving within a statutory band of 0.50000% to 15.00000% and by at most ±1 percentage point a year. The only fixed values are the prima media by risk class in art. 73, which apply solely on first registration or on a change of activity; those five figures are quoted in the scheme record. We do not publish a "typical" or "average" rate. No number given for IMPUESTO SOBRE NÓMINAS. It is set by each of the 32 states under its own fiscal code; there is no federal instrument and no national rate. We have not verified any individual state's rate or base in this pass, so we publish none. Nothing is asserted about how the IMSS SUA software resolves the malformed second bracket of the cesantía y vejez table ("1.01 SM a 1.50 UMA"). We state the defect and the only coherent reading; we did not read an IMSS instrument confirming the implementation. The Gobierno Federal shares (13.9% of UMA under art. 106 fr. III, 0.05% under art. 107 fr. III, 0.075% under art. 25, 7.143% of employer quotas under art. 148, and the cuota social under art. 168 fr. IV) are reported in notes but carry no payroll rate, because they are State transfers and never appear on a payslip or an employer liquidation. ALREADY LEGISLATED, NOT YET IN FORCE: ALREADY LEGISLATED, certain: 1 January 2027 — cesantía y vejez employer rates step to the 2027 column of the ARTÍCULO SEGUNDO TRANSITORIO (DOF 16-12-2020): 3.150 / 3.807 / 5.276 / 6.157 / 6.745 / 7.164 / 7.479 / 8.603 percent across the eight SBC bands. Further automatic steps on 1 Jan 2028, 1 Jan 2029 and 1 Jan 2030; from 1 Jan 2030 the schedule ends and the table printed in LSS art. 168 fr. II a) becomes the operative one (top bracket 11.875%). The employee rate stays 1.125% throughout — it is not part of the phase-in. ANNUAL, mechanical, dates fixed but values not yet known: 1 February 2027 — new UMA published by INEGI in January 2027 under CPEUM art. 26 ap. B and the Ley para determinar el valor de la UMA, computed from the December year-on-year INPC. This re-prices the 25-UMA ceiling, the 3-UMA threshold, the flat art. 106 fr. I quota and every UMA band of the cesantía y vejez table. 1 January 2027 — new general minimum wages fixed by CONASAMI (LFT art. 570, resolution published in DOF in December 2026). This re-prices the SBC floor in both geographic zones and the "1.00 SM" cesantía y vejez band. RE-VERIFY DEADLINES: 15 January 2027 (CONASAMI resolution in DOF, and confirm the 2027 CEAV column has taken effect) and 5 February 2027 (INEGI UMA). No other change is legislated. No pending reform to the LSS contribution rates was found in the text as amended to DOF 15-01-2026. SOURCING CAVEATS: RETRIEVAL — what was read live versus by archive. Read live and directly: - DOF, Unidad de Medida y Actualización 2026 (INEGI), https://dof.gob.mx/nota_detalle.php?codigo=5778072&fecha=09/01/2026 — daily 117.31, monthly 3,566.22, annual 42,794.64, in force 1 Feb 2026. - DOF, DECRETO de reformas a la LSS y la LSAR en materia de pensiones, 16-12-2020, full text retrieved via https://www.dof.gob.mx/nota_to_doc.php?codnota=5607729. The two transitional TABLES in that decree are published by DOF only as embedded images; they were extracted from the DOF's own document file and read directly, giving the full 2023–2030 CEAV grid quoted above. The amended art. 168 fr. II text was read as text. - DOF, CONASAMI Resolución de salarios mínimos vigentes desde 1-01-2026 (published 09-12-2025), via https://www.dof.gob.mx/nota_to_doc.php?codnota=5775534 — 315.04 and 440.87. Read via Internet Archive snapshots of the Cámara de Diputados consolidated texts, because diputados.gob.mx refused connections from two independent networks (connection refused / timeout, not a bot block) and imss.gob.mx returns 403 to every non-interactive client: - Ley del Seguro Social, snapshot 25-02-2026 of https://www.diputados.gob.mx/LeyesBiblio/pdf/LSS.pdf, 181 pp, cover states "Última reforma publicada DOF 15-01-2026". - Ley del INFONAVIT, snapshot of https://www.diputados.gob.mx/LeyesBiblio/pdf/LIFNVT.pdf, 93 pp, "Última Reforma DOF 21-02-2025". - CPEUM, snapshot of .../CPEUM.pdf, cover "Últimas Reformas DOF 02-06-2026", for the desindexación transitorios. - Ley del ISR, snapshot of .../LISR.pdf, cover "Última Reforma DOF 01-04-2024", for arts. 25 fr. VI, 28 fr. I, 93 fr. XII, 96, 151. These are byte-for-byte the official congressional consolidations, but they are archive copies. The LSS copy is current to DOF 15-01-2026; any LSS reform published between 15-01-2026 and today (08-08-2026) would not be reflected. The 15-01-2026 reform itself was checked and touches the law's general/anti-discrimination provisions, not the financing articles. The LISR copy predates any 2025 tax reform; arts. 93/96/151 were not among the provisions changed by later ISR reforms to our knowledge, but the deductibility conclusion should be re-checked against the current LISR before it is relied on for a tax computation. source_url_loads is FALSE for a specific reason: https://www.diputados.gob.mx/LeyesBiblio/pdf/LSS.pdf is the canonical location of the instrument but the host refused connections from both our network and a second, unrelated network. It appears to block traffic from outside Mexico. A Mexican client will very likely load it. DERIVED, NOT QUOTED — arithmetic we performed on verified inputs: - 25 UMA = 2,932.75/day; 89,155.50/month; 1,069,866.00/year. The statute sets a DAILY ceiling only. The monthly and annual figures are 25 x INEGI's own published monthly and annual UMA. IMSS actually computes on days in the period, so a 31-day month bills 25 x 117.31 x 31 = 90,915.25, not 89,155.50. Use the daily figure for computation; the monthly and annual values are for display and comparison. - 3 UMA threshold = 351.93/day; 10,698.66/month, same caveat. - The flat art. 106 fr. I quota, 20.4% x 117.31 = MXN 23.93/worker/day. - floor_monthly 9,582.47 is CONASAMI's own monthly statement of the general-zone minimum wage (daily x 365/12); the statutory floor is the DAILY 315.04 (or 440.87 in the ZLFN). - Employer aggregate 20.113% and employee aggregates 2.375% / 2.775% are our sums of the verified per-branch rates. - 20.4% and 1.1%/0.4% were also arithmetically reconstructed from the Décimo Noveno Transitorio's own step sizes and confirmed to land exactly on those values, which is why we state them as operative rather than as market practice. EFFECTIVE DATE. effective_from is given as 2026-02-01 because that is when the last of the current parameters came into force. In fact the set has two commencement dates: the 2026 cesantía y vejez employer rates and the 2026 minimum wage took effect 1 January 2026, while every UMA-denominated ceiling, threshold and flat quota took effect 1 February 2026. Contributions for January 2026 must use the 2025 UMA (113.14/day) with the 2026 CEAV rates — a one-month straddle that catches engines that key everything to a single annual date. Researched against primary instruments and independently challenged by a second verification pass before being served (2026-08-08). Employee and employer shares are stated separately: the employee figure is what leaves the payslip, the employer figure is cost of employment and is not a deduction.

Get it programmatically

curl https://usaref.dev/v1/mx/social-contributions
# $0.005 per call — x402 on Base (USDC). No key, no signup.
# History:    curl https://usaref.dev/v1/mx/social-contributions/history?from=2020-01-01
# Provenance: curl https://usaref.dev/provenance/mx/social-contributions

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