OSHA Compliance Deadline Calendar 2026–2027

The OSHA compliance year, in plain English

Most OSHA deadlines repeat on the same calendar dates every year, so they are easy to plan around once you know them. The four that catch employers out most often are the OSHA 300A summary posting (a window, not a single day), the March 2 electronic filing through OSHA’s Injury Tracking Application, the EPCRA Tier II chemical-inventory report due March 1, and — unique to 2026 — the November 20, 2026 HazCom employer deadline created by the HCS 2024 final rule (and its January 15, 2026 four-month extension).

The calendar above tracks every one of these with a live countdown. The table below is the same data, dated and cited, so you can verify each entry against the rule itself.

Every 2026–2027 OSHA & EPCRA deadline

“Advisory” rows are best-practice reminders (e.g. mid-year program reviews), not fixed legal due dates — they are labeled as such in each description.

The four deadlines that matter most

1 · Post the OSHA 300A summary (February 1 – April 30)

Employers that must keep injury records have to post the Form 300A annual summary of the prior year’s recordable injuries and illnesses in a conspicuous place from February 1 through April 30 (29 CFR 1904.32). The summary must be certified by a company executive. The 300 Log itself runs on the calendar year: 1904.32(a) sets the review, summary and posting duties “at the end of each calendar year,” so the new Log opens onJanuary 1 — a month before the posting window. Waiting until February 1 leaves January’s recordable cases with nowhere to go.

2 · File electronically through the ITA (by March 2)

Separately from posting, certain establishments must electronically submit their injury data through OSHA’s Injury Tracking Application by March 2 (29 CFR 1904.41 (88 FR 47346, Jul 21 2023)). Who must file, and what they file, depends on size and industry:

The Tier B requirement (100+ employees in an Appendix B high-hazard industry; in construction, NAICS 2381 only) is the one contractors in that code miss: it requires submitting the detailed Forms 300 and 301, not just the 300A summary. The 250-employee tier (300A only) still applies beside it.

3 · File EPCRA Tier II (March 1)

This one is EPA, not OSHA. Under EPCRA §312 (40 CFR 370.45), a facility that stored a hazardous chemical above the reporting threshold at any point in the prior year must file a Tier II inventory with its State Emergency Response Commission (SERC), Local Emergency Planning Committee (LEPC), Local fire department with jurisdiction over the facility by March 1. The default threshold is 10,000 lb; for an Extremely Hazardous Substance it drops to the lower of 500 lb or the substance’s Threshold Planning Quantity.

4 · Meet the November 20, 2026 HazCom deadline

The HCS 2024 final rule aligns the Hazard Communication Standard with primarily GHS Revision 7. After the January 15, 2026 four-month extension, the in-force employer deadline for hazardous substances is November 20, 2026: by that date employers must update workplace labeling, the written HazCom program, and employee training (29 CFR 1910.1200). For mixtures, manufacturers comply by November 19, 2027 and employers by May 19, 2028.

Worked examples

A 40-person mechanical contractor. Two reasons it does not file electronically, and the second one outlasts the first: it is under 100 employees, and a mechanical contractor sits in NAICS 2382 (building equipment contractors), which is not in Appendix B at all — only 2381 is. Even at 200 employees this firm would owe the 300A under Appendix A, not the full 300 + 301 set. It still must keep a 300 Log, post the 300A from February 1 to April 30, and meet the November 20, 2026 HazCom update. If it stores more than 10,000 lb of a hazardous chemical (fuel, solvents, compressed gases), it also owes a Tier II report by March 1.

A 160-person general contractor. Now the establishment is over 100 employees in construction, so on top of posting the 300A it must electronically submit Forms 300, 301, and 300A through the ITA by March 2 (29 CFR 1904.41(a)(2)) — the detailed case-level data, not just the summary. The HazCom and (if applicable) Tier II deadlines apply the same way.

What to do next

• Subscribe once. Use “Add to my calendar (.ics)” above so every date lands in your own calendar with reminders — you will not have to remember them again.
• Confirm your ITA tier. Count employees per establishment and check whether your NAICS is in Appendix A or B; in construction only NAICS 2381 (foundation, structure and building exterior) at 100+ owes the detailed Forms 300/301; the rest of construction owes the 300A.
• Close the HazCom gap now. Relabeling, updating the written program, and retraining take time — start well before November 20, 2026.
• Check your state. State-Plan states (e.g. California, Michigan, Washington) can set different rules and dates; verify locally.

Frequently asked questions

Sources & verification

• 29 CFR 1904.41 (ITA electronic submission) — eCFR
• 29 CFR 1910.1200 (Hazard Communication) — eCFR
• HCS 2024 extension — Federal Register (Jan 15, 2026)
• 40 CFR Part 370 (EPCRA Tier II)
• OSHA recordkeeping (300/300A/301)

Regulatory facts verified 2026-10-05 against the eCFR, OSHA.gov, and the Federal Register. This calendar is a planning aid for federal requirements — it is not legal advice, and State-Plan states may set different dates.

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