## Facts

- Air Brake Systems, Inc. manufactured a non-electronic antilock brake system (MSQR-5000) and marketed it as compliant with Federal Motor Vehicle Safety Standard 121 (FMVSS 121).
- After a customer inquired about compliance, NHTSA’s Acting Chief Counsel issued two advisory opinion letters stating the system would not satisfy FMVSS 121.
- The letters reasoned that FMVSS 121 requires wheel-slip controls and warning lights, and that Air Brake’s system appeared to lack those features.
- NHTSA posted the opinion letters on its website, and Air Brake alleged resulting commercial harm.
- NHTSA did not initiate any formal statutory process to determine noncompliance or to order a recall.
- Air Brake sued, challenging both the legal interpretation in the letters and the Acting Chief Counsel’s authority to issue them.

## Issues

1. Whether NHTSA’s advisory opinion letters, including their posting on the agency website, constituted “final agency action” reviewable under the Administrative Procedure Act (APA), 5 U.S.C. § 704.
2. Whether NHTSA’s Chief Counsel (or Acting Chief Counsel) had authority to issue advisory opinion letters interpreting FMVSS 121.

## Decision

- The Sixth Circuit affirmed summary judgment for NHTSA.
- The court held the opinion letters were not “final agency action” under the APA and therefore were not judicially reviewable in this posture.
- The court held the Chief Counsel had delegated authority to issue advisory interpretive letters regarding federal motor vehicle safety standards.

## Legal Principles

- Under the APA, an agency action is “final” only if (1) it marks the consummation of the agency’s decision-making process and (2) it determines rights or obligations or produces legal consequences.
- Informal interpretive opinion letters that are expressly tentative, based on assumed or submitted facts, and nonbinding on the agency and regulated parties generally lack the legal effect required for APA finality.
- Practical economic effects from an agency’s nonbinding guidance, including reputational or market harm from public posting, do not by themselves create final agency action absent a change in legal status or enforceable obligations.
- Agency officials may issue advisory interpretive guidance when authority is delegated through statute or internal agency delegation, even if such guidance is not itself reviewable as final agency action.

## Conclusion

Because NHTSA’s advisory letters did not complete a binding compliance or recall determination and imposed no legal obligations or consequences, they were not final agency action reviewable under the APA; the court also upheld the Chief Counsel’s authority to issue such interpretive opinions.


Air Brake Sys., Inc. v. Mineta, 357 F.3d 632 (6th Cir. 2004)