The Driver Investigation History File: §391.53 Safety Performance History, Explained

There's a file most small carriers don't know they're required to keep — and folding it into the driver qualification file, which is where most people put it, is itself a compliance problem.

It's the driver investigation history file, required by 49 CFR §391.53. It holds the results of the background investigation you're required to run on every driver you hire: the safety performance history you collect from their previous employers. It has its own contents list, its own access restrictions, and its own retention clock. Auditors ask for it by name.

This guide covers what the investigation requires, what goes in the file, the deadlines that apply, and how the 2023 Clearinghouse change reshaped the drug-and-alcohol half of the process.

Why this file exists, and why it's separate

When you hire a driver, §391.23 requires two inquiries within 30 days of the date employment begins:

1. A motor vehicle record (MVR) from every state where the driver held a license or permit in the past 3 years — §391.23(a)(1). This goes in the driver qualification file.
2. A safety performance history investigation of every DOT-regulated employer the driver worked for in the past 3 years — §391.23(a)(2). This goes in the investigation history file under §391.53 — not the DQF.

The separation isn't bureaucratic tidiness. The investigation file contains drug and alcohol history, and §391.53(a) puts real restrictions on it:

• It must be kept in a secure location with controlled access.
• Access is limited to people involved in the hiring decision (or who control access to the data).
• Your insurer may see the file — but never the alcohol and controlled substances data.
• The data may be used only for the hiring decision. Not discipline, not performance reviews, not anything else.

A DQF gets handled constantly — the driver can review parts of it, your insurance agent may ask for pieces, an auditor pages through it. If the safety performance history is stapled inside, you've given all of those people access to confidential drug-and-alcohol records that §391.53(a)(1) says they must not see. Keep it separate.

What the investigation covers

The investigation has two tracks, both reaching back 3 years from the date of the employment application.

Track 1: General and accident history — §391.23(d)

From every previous employer for whom the applicant operated a commercial motor vehicle in the past 3 years, you must request:

• General driver identification and employment verification — confirming the person and the dates they worked there.
• Accident data — the same data elements the previous carrier records in its accident register under §390.15(b)(1), for any DOT-recordable accidents involving the driver in the 3 years before the application. The previous employer may also volunteer minor-accident detail it keeps under its own internal policies.

Track 2: Drug and alcohol history — §391.23(e)

From every DOT-regulated employer that used the driver in a safety-sensitive function subject to Part 40 testing in the past 3 years:

• Whether the driver violated the drug and alcohol prohibitions of Part 382 Subpart B or Part 40.
• Whether the driver failed to complete a substance abuse professional (SAP) program. If the previous employer doesn't know (say, they terminated the driver after the positive test), you must get documentation of SAP completion directly from the driver.
• For a driver who completed a SAP referral and stayed with that employer: any post-referral violations — alcohol results at 0.04 or higher, verified positive drug tests, or refusals (including adulterated or substituted specimens).

The Clearinghouse change: what's automated and what isn't

Since January 6, 2023, §391.23(e)(4) says employers subject to the Clearinghouse rule must use the FMCSA Drug and Alcohol Clearinghouse to satisfy Track 2 with respect to FMCSA-regulated previous employers. Your pre-employment full query — already required by §382.701(a) — now does the drug-and-alcohol inquiry work that used to require letters and faxes to each previous trucking employer.

That word FMCSA-regulated is doing a lot of work. Manual inquiries are still required in three situations:

1. Previous employers regulated by another DOT mode. If the driver did safety-sensitive work under FRA, FTA, PHMSA, FAA, or USCG rules (railroad, transit, pipeline, aviation, maritime), the Clearinghouse doesn't cover it — §391.23(e)(4)(ii) requires you to request the drug-and-alcohol history directly from those employers. The general DOT rule at §40.25 frames its own inquiry at 2 years; §391.23(e) requires 3. Cover 3 years and you satisfy both.
2. An unfinished follow-up testing plan. If the applicant is subject to follow-up testing and hasn't completed all the tests, §391.23(e)(4)(i) requires you to request the follow-up testing plan directly from the previous employer, per §40.25(b)(5).
3. The question you must ask the driver. §40.25(j) requires you to ask the applicant directly whether they tested positive or refused a pre-employment test in the past 2 years for any DOT-regulated employer that did not hire them — a gap no employer inquiry can catch, because there's no employment relationship to investigate. If the answer is yes, the driver can't perform safety-sensitive functions until they document completion of the return-to-duty process.

And the accident-history half of the investigation — Track 1 — was never automated. The Clearinghouse holds drug and alcohol violations, nothing else. You still contact every CMV employer from the past 3 years for identification, employment verification, and accident data.

Consent is not optional — in either direction

Two consent requirements, two hard stops:

• The driver must provide written consent for the release of drug and alcohol information from previous employers (§391.23(f)(1), meeting the requirements of §40.321(b)). If the driver refuses, you must not let them drive for you.
• The driver must consent to your Clearinghouse query. If they refuse, same result — §391.23(f)(2): no consent, no CMV.

Keep a copy of the written authorization in the investigation history file — §391.53(b)(1) lists it as required contents.

What goes in the file

Per §391.53(b) and §391.23(c), the file must contain, for each driver, within 30 days of the date employment begins:

1. The driver's written authorization for the drug-and-alcohol inquiries.
2. Every response received from previous employers — or documentation of good faith efforts to contact them. Each written record must include the previous employer's name and address, the date contacted (or the attempts made), and the information received. Failures to contact, and previous employers' failures to respond, must be documented.
3. For drivers with no DOT-regulated employment in the past 3 years — a common situation when you hire someone new to trucking — §391.23(c)(4) requires you to document that no investigation was possible. An empty file is a violation; a file with a dated note saying "applicant had no DOT-regulated employers in the preceding 3 years, verified against the employment application" is compliance.

If a previous employer stonewalls you, §391.23(c)(3) says to report the non-response to FMCSA using the complaint procedures at §386.12 — and keep a copy of that report in the file as part of your good-faith documentation. Your obligation is a documented good-faith effort, not a confession you can't force out of another carrier.

The deadlines, all in one place

The driver-rights entries matter to you on both sides of the table: as the hiring carrier you must notify applicants of their rights to review, correct, and rebut the information (§391.23(i)(1) — put it on your employment application), and as a previous employer you're required to respond to other carriers' investigations about your former drivers, keep a record of each request and response for 1 year (§391.23(g)(4)), and handle correction and rebuttal requests on the schedule above.

The owner-operator wrinkle

If you're an owner-operator running under your own authority, you build this file on yourself, the same way you build your own DQF:

• If you drove for other carriers in the 3 years before starting your authority, you investigate them — your former employers get the same §391.23(d) and (e) requests, and their responses go in your file. Your own pre-employment Clearinghouse query covers the FMCSA drug-and-alcohol portion.
• If you didn't — you came from construction, farming, or anywhere outside DOT regulation — you write the §391.23(c)(4) note documenting that no investigation was possible, date it, and file it.

Either way the file must exist. In a new-entrant safety audit, driver-hiring records are standard requests, and "I'm the only driver, so I didn't investigate anyone" reads as a missing record, not an exemption.

Retention and access, in plain terms

• Keep the file for the duration of the driver's employment plus 3 years — §391.53(c).
• The requesting-employer record under §40.25(i) carries its own 3-year clock from the date the driver first performs safety-sensitive duties; the §391.53(c) employment-plus-3 rule will always outlast it, so one retention policy — employment plus 3 years — covers the whole file.
• Store it separately from the DQF, access-controlled, and never share the drug-and-alcohol contents with your insurer — §391.53(a).
• Be ready to produce it: §391.53(d) requires making the file available to FMCSA or state enforcement on request, within the time period they specify.

One more distinction worth keeping straight: the investigation history file is not your Part 382 drug-and-alcohol testing file. That file holds your own program's records — test results, chain-of-custody forms, your written policy. The §391.53 file holds what other employers told you during hiring. Same confidentiality instincts, different files, different rules.

How Roadworthy HQ handles this

Roadworthy HQ tracks the investigation history file as its own module, separate from the DQF — with the §391.23 inquiry checklist per driver, the 30-day completion window on a visible countdown, good-faith-effort documentation templates, and retention dates computed automatically from each driver's employment dates. When the auditor asks for driver-hiring records, the file is already assembled and audit-ready. Start a 14-day free trial — no credit card required.

Related violation codes

The requirements covered above are cited as these violation codes in audits and roadside inspections:

• §391.23 — Previous-employer investigation not made
• §382.701 — Missing Clearinghouse pre-employment or annual query
• §391.51 — Driver qualification file incomplete