The Ultimate OSHA 300A Checklist: Your Step-by-Step Guide to the March 2nd Deadline

The annual OSHA injury and illness reporting cycle can feel like a high-stakes, regulatory sprint, culminating in the critical March 2nd deadline. For EHS professionals, this period often involves a frantic, 30-day crunch time, starting with the February 1st posting requirement to finalize, certify, and submit the previous year’s records.

This isn't just bureaucratic oversight anymore; a series of recent changes has dramatically raised the stakes. Effective in early 2025, maximum civil penalties for violations like a failure to post the summary or keeping inaccurate records saw a substantial increase. [cite: 1.1.1] Furthermore, OSHA’s expansion of data collection now requires thousands of high-hazard establishments to submit detailed, case-specific information, introducing major new risks around data accuracy and public exposure.

To help you navigate the 2026 reporting cycle (covering Calendar Year 2025 data), we've synthesized a definitive, step-by-step compliance checklist. Mastery of these four steps is essential to mitigating escalating financial penalties and managing your organization’s public risk profile.

Part 1: Defining Your Compliance Scope. Who Submits What?

The first and most critical step is determining exactly what data your establishment is required to submit electronically. The requirements are tiered based on your company’s peak employee count during the preceding year (2025) and its industry classification.

Tier 1: Submission of Form 300A Summary Only (The Standard Requirement)

Your establishment must submit only the OSHA Form 300A Summary data if it meets one of the following two criteria: [cite: 1.2.1]

1. Size & Industry: The establishment had 20 to 249 employees at any point during 2025 and is classified in a high-hazard industry listed in Appendix A (e.g., Manufacturing, Construction, Warehousing).
2. Size Only: The establishment had 250 or more employees and is in an industry that is generally required to keep OSHA injury and illness records.

Tier 2: Expanded Scope: Submission of Forms 300, 301, AND 300A

This is the key change for the 2026 cycle and significantly increases the compliance burden. Establishments must submit detailed, case-specific information from their OSHA Form 300 Log and Form 301 Incident Report if they meet both of the following criteria:

1. The establishment had 100 or more employees at any point during 2025.
2. The establishment is in a high-hazard industry specifically listed in Appendix B (a list focusing on the highest hazard sectors, including Nursing Care, Trucking, and Motor Vehicle Manufacturing).

For those in Tier 2, the need for technical precision and data security is paramount (more on this in Part 3).

Part 2: The Ultimate 4-Step OSHA 300A Compliance Checklist

Once you’ve defined your submission scope, accurate compliance requires strict adherence to this four-step annual process.

Step 1: Finalize the OSHA Form 300 Log (The Foundation)

Your Log of Work-Related Injuries and Illnesses (Form 300) must be complete and accurate for all recordable incidents that occurred throughout 2025. A case is considered recordable if it is work-related, new, and results in any of the following outcomes:

• Death
• Loss of consciousness
• Days away from work
• Restricted work activity or job transfer
• Medical treatment beyond first aid (The critical distinction, see Part 4)
• Diagnosis of a significant injury or illness

This log must be retained and updated for five years.

Step 2: Calculate the Annual Summary Totals (The Detail)

The totals from your Form 300 Log must be transcribed onto the Form 300A Summary. This step is a common source of error, particularly with the two key metrics required for calculating injury rates:

Calculating Total Employee Hours Worked (The Frequent Flaw)

This figure is often incorrectly calculated, which can artificially lower your calculated injury rates and potentially raise red flags during an audit.

• INCLUSIONS: Include all hours worked by all employees: salaried, hourly, part-time, seasonal, and temporary workers under your supervision.
• EXCLUSIONS: You must explicitly exclude all hours associated with non-work time, such as vacation, sick leave, holidays, or any paid time off (PTO), even if the employees were compensated for that time.

Calculating Average Employees

The formula requires summing the number of employees paid in each pay period throughout the year and dividing that sum by the total number of pay periods. The final number must be rounded up to the next highest whole number. This ensures an accurate representation of the establishment size throughout the year, especially if your workforce fluctuates seasonally.

Step 3: Certify and Post the 300A Summary (The Public Requirement)

The completed Form 300A must be reviewed and certified by the highest-ranking company official at the establishment. The certified summary is then required to be posted in a prominent location where employee notices are customarily displayed.

• Posting Period: The Form 300A must be posted from February 1, 2026, through April 30, 2026.

A simple failure to post the 300A Summary can be categorized as a Serious or Other-Than-Serious violation, carrying a maximum penalty of $16,550 per violation. [cite: 1.1.1]

Step 4: Electronically Submit Data via the ITA (The Deadline)

All required data (Form 300A only, or Forms 300, 301, and 300A) must be submitted electronically through OSHA’s Injury Tracking Application (ITA) website.

• Submission Deadline: The deadline for submission of Calendar Year 2025 data is March 2, 2026.

Part 3: Beyond the Summary: The High-Stakes Risk of Detailed Data

For those organizations required to submit the expanded Forms 300 and 301 case details (Tier 2), the compliance task shifts from an administrative hurdle to a high-stakes data integrity issue.

The PII Compliance Catastrophe

The most significant new risk is the potential for unintentionally exposing Personally Identifiable Information (PII). OSHA intends to make much of this establishment-specific data publicly available, and the required submission fields for 300/301 data include things like Job Title, Date of Birth, and detailed incident narratives.

OSHA explicitly warns users not to include any personally identifiable information (such as names, phone numbers, or Social Security numbers) in the narrative fields. If a hurried safety professional overlooks the necessary redactions in the narrative text during a manual CSV compilation, a minor administrative error instantly transforms into a severe legal and privacy breach liability, exposing the company to liabilities far exceeding typical OSHA fines.

The Technical Pain Point: CSV Upload Failures

For bulk submissions, the CSV file upload feature is essential, but it is prone to technical rejection. A failed submission due to technical formatting issues can mean the March 2nd deadline is missed, exposing the establishment to immediate penalties. [cite: 14, 2.1.1]

Manual compilation frequently leads to rejection due to issues such as:

• Establishment Mismatch: The CSV file’s header must contain an establishment_name field that matches the name registered in the ITA system exactly.
• Date Format Violation: All date fields (e.g., date_of_incident) must conform strictly to the mm-dd-yyyy or mm/dd/yyyy format.
• Non-Unique Case Number: The case_number field must be unique within that specific establishment's submission.

Part 4: The High-Value Utility: Mastering DART and TCIR

The Form 300A Summary provides the raw data needed to calculate the two key standardized safety metrics: the Total Case Incident Rate (TCIR) and the Days Away, Restricted, or Transferred (DART) Rate. These metrics are critical for internal performance assessment, reporting to insurers, and avoiding regulatory flagging.

What’s the Difference?

Both rates use the same formula, normalizing for the size of the workforce using a constant of 200,000 (which represents 100 full-time employees working 40 hours per week for 50 weeks per year). The difference lies in the numerator:

The Critical Connection to Audits and Insurance

The integrity of these rates relies heavily on the Total Employee Hours Worked (the denominator), as discussed in Part 2. If your calculation includes paid non-work time (PTO), you are artificially inflating the denominator, which results in an artificially low TCIR or DART rate.

A rate that is significantly below the industry benchmark (Bureau of Labor Statistics national average) can, paradoxically, raise a regulatory red flag, leading to an investigation into the integrity of your recordkeeping practices. Furthermore, these rates are critical inputs for determining Workers’ Compensation insurance premiums and your Experience Modification Rate (EMR).

The Foundational Integrity Check: Recordable vs. First Aid

The foundation of all safety metrics is the initial classification of an injury. If injuries are misclassified, either over-recorded to be "safe" or under-recorded to minimize the log, it distorts the final TCIR and DART rates. The defining criterion for a recordable case is Medical Treatment Beyond First Aid.

Conclusion: Mitigating Risk with Precision

The 2026 reporting cycle requires organizations to move away from reactive, deadline-driven recordkeeping. The combination of expanded electronic submission requirements, heightened financial penalties, and the risk of public PII exposure means that success hinges on technical precision and foundational accuracy.

Automating the data aggregation, the calculation of Total Employee Hours Worked (correctly excluding PTO), and the technical formatting for the ITA (especially for the expanded 300/301 data) is the most effective hedge against the rising risks. This proactive approach ensures a stress-free March 2nd deadline and provides real-time visibility that can ultimately lead to better safety outcomes and a stronger EMR standing.