§391.23 requires the carrier to investigate every applicant's employment history at every DOT-regulated employer in the prior 3 years. Two separate inquiries are required: (1) a state MVR pull from every state where the driver held a CDL or CMV-operator's license in the prior 3 years (§391.23(a)(1)), and (2) a safety performance history inquiry from every prior DOT-regulated employer (§391.23(a)(2)), including any drug-and-alcohol testing history that falls under §40.25.
Timing
The inquiries must be completed within 30 days of hire. The carrier files the responses in the Driver Investigation History File per §391.53 — a file separate from the DQF and retained for 3 years from the inquiry date. Some carriers file inquiries inside the DQF; FMCSA prefers the separation.
What the §40.25 D&A inquiry covers
- Any verified positive controlled-substances test result within the prior 3 years
- Any alcohol test with concentration of 0.04 or greater within the prior 3 years
- Any refusal to be tested
- Any other violation of §40 or §382 subpart B
- Whether the driver completed the SAP return-to-duty process (§40 subpart O)
How to prevent it
- Send inquiries on day 1 of employment — most former employers take 2–3 weeks to respond.
- Track the 30-day clock. Inquiries pending at day 31 are findings, even if the response is in transit.
- Document the inquiry sent and the response (or non-response). A "no response after multiple requests" record satisfies §391.53 if you can show good-faith effort.
- §40.25 D&A inquiries go in the Driver Investigation History File, not the DQF — but a copy can also live in the §382.401 D&A file.
How Roadworthy HQ helps
Roadworthy HQ does not track §391.23 inquiries today: there is no inquiry log, no deadline countdown, and no upload screen for the investigation file. Keep the inquiries, the responses, and your good-faith-effort notes in your own file. What the app does hold for a new hire is the rest of the qualification file, the pre-employment test result, and the pre-employment Clearinghouse query.