NHTSA delays US seat belt reminder compliance to September 1, 2028 in answer to petitions

The US National Highway Traffic Safety Administration (NHTSA) published an interim final rule on seat belt reminder systems in the Federal Register on April 6, 2026. The document, published under number 2026-06614 at 91 FR 17144, carries the title "Federal Motor Vehicle Safety Standards; Occupant Crash Protection, Seat Belt Reminder Systems" and sits under 49 CFR 571, the Federal Motor Vehicle Safety Standards. It is a US-market rule, issued through the Department of Transportation, and applies to FMVSS requirements rather than to any other market.

The rule responds to petitions for reconsideration of NHTSA's January 2025 final rule on seat belt warning requirements in FMVSS No. 208, "Occupant crash protection." Per the document's SUMMARY, the interim final rule amends those warning requirements, delays the compliance dates and makes technical clarifications to the regulatory text, while NHTSA denies the remainder of the requests. The compliance date is now September 1, 2028, with optional early compliance permitted, and multi-stage manufacturers and alterers have an additional year to comply. Comments on the document are due no later than May 21, 2026, and the rule is effective April 6, 2026.

What the rule responds to

This interim final rule answers petitions for reconsideration - a procedural mechanism in US rulemaking by which parties ask the issuing agency to revisit points in a final rule. The document lists seven distinct petitions in its response section, each with a request and the agency's response. The subjects span the practical details of how a seat belt reminder must behave in the cabin.

The petition topics listed in the document are:

• lead time for compliance
• the duration of the first-phase audible warning for the front seat belt
• visibility of the rear seat belt visual warning in vehicles with no driver's designated seating position
• the trigger requirement for the front seat belt audible warning
• occupancy criteria for the rear seat belt warning system
• the rear seat change-of-status warning requirement for two-door vehicles
• telltales associated with multiple front outboard seats

On the lead-time question, the January 3, 2025 final rule had established a compliance date of September 1, 2026 for the front seat belt warning system requirements and September 1, 2027 for the rear seat belt warning system requirements, with optional early compliance. The document's response section states that this interim final rule provides an additional year of lead time for the rear seat belt requirements and an additional two years for the front seat belt requirements.

Official text and the docket

The Office of the Federal Register describes its FederalRegister.gov site as "a prototype of a 'Web 2.0' version of the daily Federal Register" and states that it "is not an official legal edition of the Federal Register." Per the page, the official electronic format is the PDF linked in the document sidebar; the document spans pages 17144-17159, 16 pages. Those relying on the site for legal research are advised by the Office of the Federal Register to verify their results against an official edition of the Federal Register.

The docket page records, at the time it was read, that comments are no longer being accepted and that 17 comments have been received at Regulations.gov. Per the same page, agencies review all submissions and may choose to redact or withhold certain submissions, or portions thereof, and submitted comments may not be available to be read until the agency has approved them.

Why an interim final rule, effective immediately

An interim final rule is a device that lets an agency publish a rule with immediate effect while still taking comment afterward. The document's section IV is headed "Basis for Issuing an Interim Final Rule Effective Immediately," with subheadings covering the good cause justification under the APA for waiving prior notice and opportunity for comment, and the justification under the APA and Safety Act for an immediate effective date. The document also carries a section titled "Request for Comment," consistent with the interim-final-rule structure of acting now and inviting comment on the answers already given.

Scope and market

This rule amends 49 CFR 571 - the Federal Motor Vehicle Safety Standards - and is a United States federal requirement. It is not a WLTP-type test procedure, not a UN regulation, and carries no force in other markets. Readers outside the US should not read the September 1, 2028 compliance date as anything other than a US-market date under NHTSA's standards.

How to check this yourself

Per the Office of the Federal Register, the document's own page advises that "those relying on it for legal research should verify their results against an official edition of the Federal Register."