Checking a Driver's Previous Employers: Drug, Alcohol, and Safety History
When you hire a driver, 49 CFR 391.23 requires you to look into their safety history with past DOT-regulated employers. Since January 6, 2023, the Clearinghouse handles most of the drug and alcohol part for FMCSA employers, but not all of it. Here is what you still have to ask for, how far back to go, and your deadlines.
Updated September 28, 2026 · Checked against the federal regulations
What 391.23 requires
Section 391.23(a)(2) requires an investigation of each driver's safety performance history with DOT-regulated employers during the preceding three years.
The replies, or proof of your good faith efforts to get them, must go in the driver investigation history file within 30 days of the date the driver's employment begins (391.23(c)(1)).
You can investigate by phone, letter, email, interview, or another method. For each previous employer, keep a written record of the employer's name and address, the date you contacted them or tried to, and what they told you. If an employer does not respond, document that too.
What to ask every previous CMV employer
Under 391.23(d), you must ask all employers that had the driver operate a CMV in the previous three years for at least the items below. Your request must say exactly where to send the information.
The Clearinghouse holds drug and alcohol violation information. It does not hold employment verification or accident history, so this part of the check still goes directly to previous employers.
- General driver identification and employment verification.
- Accidents involving the driver in the three years before the application date, using the data elements in 390.15(b)(1).
- Any other accidents the previous employer chooses to share.
The drug and alcohol questions
Section 391.23(e) covers previous DOT-regulated employers where the driver held a safety-sensitive job that required Part 40 drug and alcohol testing in the previous three years. You must find out:
- Whether the driver violated a drug or alcohol rule in Part 382 Subpart B or Part 40 in the previous three years.
- Whether the driver failed to start or finish a rehabilitation program prescribed by a Substance Abuse Professional (SAP).
- For a driver who finished a SAP referral and stayed with that employer: any later alcohol test of 0.04 or higher, verified positive drug test, or refusal (including adulterated or substituted results).
How the Clearinghouse changed this after January 6, 2023
As of January 6, 2023, FMCSA-regulated employers must use the Drug and Alcohol Clearinghouse to meet the drug and alcohol part of 391.23 for previous employers that are FMCSA-regulated (391.23(e)(4) and 382.413(b)). The driver must consent to the Clearinghouse query. If they refuse, they cannot drive a CMV for you.
You still must contact previous employers directly in two cases:
- Follow-up testing plan: if the driver is subject to follow-up testing and has not finished all follow-up tests, request the follow-up testing plan directly from the previous employer.
- Other DOT agencies: if the driver was tested under a DOT agency other than FMCSA, request the drug and alcohol information directly from those employers. You need the driver's written consent to give to that employer.
Driver rights, confidentiality, and record keeping
Before any hiring decision, you must tell drivers with DOT-regulated work in the last three years, in writing (for example, on the application), that they have the right to review what previous employers send you, to have errors corrected, and to attach a rebuttal. If a driver asks in writing, you must provide the information within five business days.
Previous employers must respond to your request within 30 days, even if they have nothing to report.
Use the information only to decide whether to hire the driver. Keep it in a secure file with limited access. Do not share drug or alcohol information with your insurer.
Keep the safety performance histories for a driver you hire for as long as they work for you plus three years (391.53(c)).
Pact Compliance can run the pre-employment Clearinghouse query and keep the results with your hiring records.
Common questions
How far back do I have to check a driver's previous employers?
Three years. Section 391.23 requires you to look at the driver's history with DOT-regulated employers during the preceding three years.
What is the deadline?
The replies, or your documented good faith efforts, must be in the driver investigation history file within 30 days of the date the driver's employment begins (391.23(c)(1)).
Does the Clearinghouse query replace calling previous employers?
Only for the drug and alcohol questions about FMCSA-regulated employers. You still ask previous employers for employment verification and accident history, for a follow-up testing plan if follow-up tests are unfinished, and for drug and alcohol information from employers under other DOT agencies.
What if a previous employer never responds?
Document each attempt: the employer's name and address, the dates you tried, and that no response came. Section 391.23(c)(3) says you should report the failure to FMCSA and keep a copy of the report in the file.
What if the driver had no DOT-regulated jobs in the last three years?
Put documentation that no investigation was possible in the driver investigation history file within the same 30 days (391.23(c)(4)).
Sources
- 49 CFR 391.23 (eCFR)
- 49 CFR 382.413 (eCFR)
- 49 CFR 391.53 (eCFR)
- 49 CFR 40.25 (eCFR)
- 49 CFR 382.701 (eCFR)