Workplace Accident Report Mexico (Reporte de Accidente de Trabajo)

A Workplace Accident Report Mexico (Reporte de Accidente de Trabajo) is the formal internal document through which an employer records, investigates, and reports a workplace accident (accidente de trabajo) — an event that occurs during or as a consequence of the performance of the work and that produces a bodily injury, functional disturbance, or death in the worker — as defined by Article 474 of the Ley Federal del Trabajo (LFT).

The legal framework governing workplace accident reporting in Mexico involves three distinct normative layers. First, the Ley Federal del Trabajo Articles 472 through 514 establish the substantive rights and obligations of employers and workers in relation to occupational risks (riesgos de trabajo). Article 474 LFT defines accidente de trabajo as any bodily injury or functional disturbance, immediate or subsequent, or death produced suddenly as a result of work, regardless of the place where the accident occurs — including in-itinere accidents (accidents during the normal journey between the worker's home and the workplace) under Article 474 LFT as interpreted by the Suprema Corte de Justicia de la Nación (SCJN). Article 504 LFT establishes specific employer obligations following a workplace accident: preserving evidence at the accident scene, providing immediate medical attention, and reporting the accident to the competent authority.

Second, the Ley del Seguro Social (LSS), published in the Diario Oficial de la Federación on 21 December 1995, governs the IMSS's role in providing benefits to injured workers and receiving accident notifications. Article 51 LSS requires the employer to report any presumed occupational accident or disease to the IMSS within 24 hours of its occurrence, using the IMSS ST-7 form (Aviso para Calificar Probable Accidente de Trabajo) submitted through the IMSS employer portal (IDSE). Article 58 LSS establishes the workers' entitlements following a workplace accident classified as a riesgo de trabajo: medical care, prosthetics, medications, and rehabilitation at no cost; a temporary disability subsidy (subsidio por incapacidad temporal) equal to 100% of the Salario Diario Integrado (SDI) during the incapacity period under Article 58, Fraction I LSS; and a permanent disability pension or proportional indemnity under Articles 58–70 LSS if the worker sustains a permanent injury.

Third, NOM-021-STPS-1994, titled 'Requerimientos y Características de los Informes de los Riesgos de Trabajo que Ocurran, para Integrar las Estadísticas,' establishes the minimum content requirements for workplace accident and occupational disease reports maintained by employers for STPS statistical and inspection purposes. The NOM requires that accident reports include: identification of the injured worker, description of the accident event, location and time, immediate cause and root cause, severity of injury, days lost, and corrective actions implemented.

The Comisión Mixta de Seguridad e Higiene (Joint Safety and Hygiene Commission) established under Articles 509–514 LFT has a mandatory role in accident investigation — the Commission must participate in the investigation of all significant accidents and must review the completed accident report before it is finalized. The STPS Inspección del Trabajo reviews the employer's accident records during workplace inspections and may cite the employer for failure to investigate accidents, to implement corrective actions, or to maintain the required statistics under NOM-021-STPS-1994.

A Workplace Accident Report Mexico must be completed every time a workplace accident occurs — regardless of severity, whether medical treatment was required, or whether the accident resulted in lost work time. The LFT Article 504 obligation to preserve evidence and report to the IMSS under LSS Article 51 applies to all incidents meeting the Article 474 LFT definition of accidente de trabajo.

The report is required immediately — within 24 hours under LSS Article 51 — following any accident that causes a worker to seek medical attention beyond first aid, that results in temporary incapacity preventing the worker from returning to work, that causes a permanent injury or disability, or that results in death. For fatal accidents, the employer must also report to the STPS within 24 hours under Article 504 LFT and to the Ministerio Público (Fiscalía) if the accident may involve criminal liability for the employer or a third party.

A Workplace Accident Report Mexico is needed even for minor injuries that do not require IMSS medical attention — near-miss incidents (cuasi-accidentes) and first-aid-only incidents must be documented internally to satisfy NOM-021-STPS-1994 statistical reporting obligations and to identify hazard trends before a more serious accident occurs. STPS inspectors review near-miss and first-aid incident records to assess the employer's proactive safety management.

The report is required when an accident occurs during remote work (teletrabajo) — Article 474 LFT as interpreted in the context of the 2021 teletrabajo reform (Articles 330-A–330-K LFT) extends accidente de trabajo classification to accidents occurring during working hours at the teleworker's designated remote work location. Employers must apply the same accident reporting procedure to teletrabajo accidents as to in-person workplace accidents.

The document is needed whenever the Comisión Mixta de Seguridad e Higiene is called to investigate an accident — the Commission uses the accident report as its primary investigation record and must document its findings and corrective action recommendations in its Acta de Reunión.

A Workplace Accident Report Mexico is also essential when the worker contests the employer's characterization of an event as a common risk (riesgo general) rather than a workplace risk (riesgo de trabajo) before the IMSS or the Tribunal Laboral — the contemporaneous accident report, completed as close to the event as possible, is the most authoritative evidence of the circumstances surrounding the accident.

A complete Workplace Accident Report Mexico must contain the following elements to satisfy LFT Article 504 obligations, IMSS ST-7 reporting requirements, NOM-021-STPS-1994 statistical content requirements, and STPS inspection documentation standards.

Employer and Workplace Identification: Full legal name (razón social) of the employer, RFC (Registro Federal de Contribuyentes), IMSS Registro Patronal, STPS employer registration number, workplace address where the accident occurred, and the IMSS risk class (clase de riesgo I–V) applicable to the worker's activity. For multi-site employers, the specific facility where the accident occurred must be identified.

Injured Worker Information: Full name, CURP (Clave Única de Registro de Población), RFC (if applicable), NSS (Número de Seguridad Social assigned by IMSS), job title (puesto), department and work area, seniority (antigüedad), shift worked at the time of the accident, daily salary (salario diario) and Salario Diario Integrado (SDI), and whether the worker is registered with the IMSS as an active insured worker (trabajador asegurado) at the time of the accident.

Accident Description and Circumstances: The exact date, time (hora), and location of the accident; a detailed narrative description of what the worker was doing at the moment of the accident, the sequence of events leading to the injury, the immediate cause of the accident (causa inmediata — the direct physical cause: fall, struck by object, chemical splash, electric contact), and any witnesses present. The description must be sufficiently detailed to identify the causal mechanism for root-cause analysis and for IMSS ST-7 completion.

Nature and Severity of Injury: Description of the injury sustained — type of injury (fractura, laceración, quemadura, contusión, intoxicación, lumbalgia), body part(s) affected, whether first aid was administered at the workplace, whether the worker was referred to IMSS medical services, and the preliminary severity assessment: (a) accidente sin incapacidad (no time lost), (b) accidente con incapacidad temporal (temporary disability — worker cannot work), (c) accidente con incapacidad permanente parcial (permanent partial disability), (d) accidente con incapacidad permanente total (permanent total disability), or (e) accidente mortal (fatal accident). This classification determines the IMSS benefit entitlement under LSS Articles 58–70.

Root-Cause Analysis: A structured analysis identifying the root causes of the accident beyond the immediate physical cause — including contributing factors such as: inadequate personal protective equipment (EPP), deficient training, failure of safety systems, poor housekeeping, fatigue, inadequate supervision, unsafe work procedure, or environmental conditions. The root-cause analysis should follow a recognized methodology (5 Whys, Fishbone/Ishikawa, SCAT analysis) and must identify systemic failures in the safety management system that require corrective action.

IMSS Notification Record: Documentation that the IMSS ST-7 form (Aviso para Calificar Probable Accidente de Trabajo) was submitted through the IMSS IDSE portal within 24 hours of the accident under LSS Article 51, with the IMSS folio number confirming receipt. If the worker is not IMSS-registered (a violation of LSS Article 15), the report must document the employer's obligation to cover all accident-related medical costs directly.

Corrective Actions: A table of specific corrective and preventive actions identified as a result of the accident investigation, each with: description of the measure, person responsible (nombre y cargo), target implementation date, and verification method. Actions must address each identified root cause and must be tracked to closure. The Comisión Mixta de Seguridad e Higiene must review and approve the corrective action plan under Articles 509–514 LFT and NOM-019-STPS-2011.

Signatures and Authorization: Signatures of the accident investigator, the injured worker or their representative, the supervisor of the work area, the safety coordinator, and at least one member of the Comisión Mixta de Seguridad e Higiene. The date of investigation completion must be recorded. Forms-legal.com provides this accident report template as a compliance starting point; employers in high-risk industries should supplement this document with sector-specific investigation protocols required by applicable NOMs and consult a Técnico en Seguridad e Higiene registered with the STPS for complex accident investigations.