Article 133, section XIV of Mexico's Federal Labor Law (LFT) bars employers from requiring a non-pregnancy certificate to hire, retain or promote a worker. It is the first line to check when a global onboarding template reaches a plant in San Luis Potosí. The rest takes more reading: Mexico has no blanket rule that every new hire must pass pre-employment medical exams, yet several standards require exams for specific jobs, and the results count as sensitive personal data.
Are pre-employment medical exams required in Mexico?
Not across the board. What the LFT does say sits in three articles:
- Article 134, section X, requires workers to undergo the medical checks set in the internal work rules and other rules in force at the company, to confirm they have no work-related disability or illness and no contagious or incurable disease.
- Article 423, section VIII, says the internal work rules (reglamento interior de trabajo) must state when and how workers take prior or periodic medical exams.
- Article 174 requires workers aged 15 to 17 to obtain a medical certificate of fitness for work.
The Federal Regulation on Occupational Safety and Health (RFSST, DOF, Mexico's Official Gazette, November 13, 2014) adds in article 7, section IX, that employers must order the medical exams that the regulation and the standards require for occupationally exposed personnel. The regulation names entry exams explicitly only once, in article 67, which covers agricultural work.
In Mexico, a pre-employment exam becomes mandatory through a job-specific standard or through your own internal work rules. If headquarters wants every hire examined, the reglamento interior is the place to write it down.
Where Mexican standards do require a medical exam
Work at heights is the clearest case. NOM-009-STPS-2011, the standard issued by the STPS (Mexico's federal labor ministry) for work above 1.80 m (about 5 ft 11 in), requires medical exams for workers who "will perform" that work (section 5.10), at least once a year (14.1). Each exam must be on paper or in electronic form and carry the worker's name, the medical evaluation, and the physician's name, signature and cédula profesional, Mexico's professional license number (14.2). The rest of that standard is covered in our guide on work at heights in Mexico under NOM-009.
Noise is the second. NOM-011-STPS-2001 applies its hearing conservation program wherever workers are exposed to 85 dB(A) or more (section 5.5), requires a specific medical exam for each of them every year (8.6), and requires that each worker be told the results (5.7). Program records are kept for five years (8.8.1).
Its Reference Guide I, which the standard itself labels non-mandatory, proposes a baseline audiogram for every worker assigned to an area above 85 dB(A), taken after at least 14 hours without noise exposure (I.3), and comparing each later audiogram against it (I.10). A baseline audiogram at hiring is what gives every later hearing test something to be compared against.
If your US sites run a hearing conservation program, the structure will look familiar; the thresholds and intervals to audit against in Mexico are those of NOM-011. The RFSST repeats the exam duty for personnel exposed to vibration, special lighting and ionizing radiation (articles 34 to 36).
What should a global onboarding template drop?
Start with pregnancy testing. Under LFT article 133, section XIV, requiring proof of non-pregnancy is prohibited at hiring, during employment and for promotion. Remove pregnancy testing from any hiring exam package used in Mexico.
Next, check how health data moves. Mexico's Federal Law on Protection of Personal Data Held by Private Parties (LFPDPPP) was replaced by a new law published in the DOF on March 20, 2025. Article 2, section VI, lists present or future health status among sensitive personal data, and article 8 requires the data subject's express written consent to process it, through a handwritten signature, an electronic signature or another authentication mechanism. Article 12 asks the company to make reasonable efforts to keep the processing period of sensitive data to the minimum necessary.
In practice that means a privacy notice specific to medical exams, a consent form signed by each worker, and a flow where Human Resources receives the fitness-for-the-job determination while the clinical file stays with the physician. A generic website form is the wrong channel for any of it.
Why does the first year on the job matter so much?
Nationwide, 48.2% of work accidents and occupational illnesses happen to people with less than a year in their position, according to the IMSS, the Mexican Social Security Institute, in its statistical report (Memoria Estadística 2025, table VII.12). The hiring exam and onboarding training cover that window.
San Luis Potosí adds a regional pattern. The state recorded 13.9 occupational illnesses per 10,000 workers in 2025, against 9.0 nationally, and 480 of its 683 cases, 70%, were shoulder injuries, carpal tunnel syndrome and tenosynovitis, typical of assembly lines (IMSS, Memoria Estadística 2025, table VII.27). On an assembly line, the hiring exam is the first record of a worker's shoulders and hands. Ergonomic risk factors fall under NOM-036-1-STPS-2018, and the way work injuries feed your social security costs is explained in our guide to the IMSS work risk premium.
Building an exam package by job profile
The physician sets the package from the job hazard analysis. This table is a starting point for that conversation:
| Job or exposure | Entry test | Basis |
|---|---|---|
| Work above 1.80 m, aerial lifts included | Medical fitness exam | NOM-009-STPS-2011, 5.10 and 14.1 |
| Areas at 85 dB(A) or more | Audiometry | NOM-011-STPS-2001, 8.6, and Reference Guide I |
| Dust, fumes or vapors | Spirometry | Physician's judgment based on the hazard analysis |
| Assembly and manual material handling | Musculoskeletal exam; X-rays if the physician orders them | Physician's judgment |
| Emergency brigades and heavy physical work | Electrocardiogram if the physician orders it | Physician's judgment |
| Every position | General medical exam | Internal work rules (LFT art. 423, section VIII) |
SIISA Consultores coordinates occupational health exams for plants in San Luis Potosí with an allied physician who holds a sanitary license: pre-employment and annual exams, audiometry, spirometry, electrocardiograms and X-rays, packaged by position. Because results are sensitive data, SIISA does not collect them through web forms.
Frequently asked questions
What pre-employment exams does an automotive plant in Mexico usually request?
There is no single package: the physician sets it from each job's hazards. A sensible base is a general exam for every hire, audiometry where noise reaches 85 dB(A) or more (NOM-011-STPS-2001) and a fitness exam for anyone who will work above 1.80 m (NOM-009-STPS-2011). On assembly lines, shoulder and hand checks matter because 70% of occupational illnesses in San Luis Potosí affect the upper limbs (IMSS, Memoria Estadística 2025).
What medical exams does NOM-011 require?
NOM-011-STPS-2001 requires a specific medical exam every year for each worker exposed to 85 dB(A) or more (section 8.6) and that each worker be informed of the results (5.7). Its non-mandatory Reference Guide I proposes pure-tone audiometry, a baseline audiogram and verification audiograms every six months from 85 dB(A).
How should we handle the health data these exams produce?
Health status is sensitive personal data under Mexico's LFPDPPP (art. 2, section VI), so processing it requires each worker's express written consent, by handwritten or electronic signature (art. 8). Use a privacy notice specific to medical exams and send Human Resources only the fitness-for-the-job result.
Who performs pre-employment medical exams for plants in San Luis Potosí?
Laboratories, clinics and occupational health providers offer the service in the metro area. SIISA Consultores coordinates it for plants in San Luis Potosí, Villa de Reyes, Soledad and the industrial zone through an allied physician with a sanitary license, including audiometry, spirometry, electrocardiograms and X-rays.
