49 CFR § 391.53 — Driver investigation history file
49 CFR — Transportation · FMCSA / DOT
49 CFR 391.53 requires a separate file from the DQF — the Driver Investigation History File (DIHF) — containing the prior-employer safety performance information collected under 49 CFR 391.23. The DIHF is access-restricted (only authorized employees, the driver, and DOT auditors) to protect prior-employer confidentiality. Without a properly-maintained DIHF, prior employers are less likely to cooperate with future safety inquiries — the whole prior-employer verification ecosystem depends on confidentiality. Carriers commonly conflate the DIHF with the DQF; they are required to be SEPARATE files.
Regulation summary
Each motor carrier must maintain a driver investigation history file (DIHF) for every driver, separate from the DQF, containing responses received from previous employers concerning the driver's safety performance under 49 CFR 391.23. The DIHF includes general safety information, drug and alcohol testing history (per 49 CFR 40.25), and accident records. The DIHF must be retained for 3 years after the driver leaves the carrier. The DIHF is kept separate from the DQF to protect the prior employer's confidentiality and to allow for the more restricted access required by 49 CFR 391.53(d) (only authorized employees, the driver, and DOT representatives may access it).
Who must comply
Every motor carrier hiring CMV drivers. The DIHF requirement is independent of fleet size or operating authority. Owner-operators with their own authority must maintain a DIHF for themselves.
What happens if violated
Civil monetary penalties: $1,100 to $16,550 per violation per driver. Common citations: no DIHF on file, DIHF commingled with the DQF, DIHF access not restricted as required by 49 CFR 391.53(d). Auditors increasingly check for proper DIHF separation during Compliance Reviews.
Implementation checklist
- Create a DIHF for every driver SEPARATE from the DQF (electronic folder or paper file).
- Document all prior-employer inquiries under 49 CFR 391.23 in the DIHF.
- Retain prior-employer responses (whether responsive or non-responsive) in the DIHF.
- Restrict DIHF access to authorized employees, the driver, and DOT representatives per 49 CFR 391.53(d).
- Train HR and safety staff on the DIHF vs DQF separation requirement.
- Retain the DIHF for 3 years after the driver's separation per 49 CFR 391.53(c).
- For electronic DIHFs, use access controls to enforce the restricted-access requirement.
- Audit DIHFs quarterly to ensure they are not commingled with DQFs.
Common misinterpretations
- Misinterpretation: 'The DIHF can be part of the DQF.' Reality: 49 CFR 391.53 requires the DIHF to be SEPARATE from the DQF. The reason is access restrictions — the DIHF contains confidential prior-employer information protected under 391.53(d), while the DQF is broadly accessible to compliance staff.
- Misinterpretation: 'I only need prior-employer responses for CDL drivers.' Reality: 49 CFR 391.53 applies to every CMV driver, CDL or non-CDL.
- Misinterpretation: 'A DIHF only contains drug and alcohol testing history.' Reality: The DIHF contains all responses received under 49 CFR 391.23 — general safety performance, drug and alcohol testing history (per 49 CFR 40.25), and accident records. Plus any later prior-employer inquiries (e.g., for litigation or insurance).
Frequently asked questions
What is the Driver Investigation History File (DIHF)?
A file separate from the DQF containing responses received from previous employers concerning the driver's safety performance under 49 CFR 391.23. Required to be access-restricted to protect prior-employer confidentiality.
Why is the DIHF separate from the DQF?
Access restrictions. The DIHF contains confidential prior-employer information protected under 49 CFR 391.53(d) — accessible only to authorized employees, the driver, and DOT representatives. The DQF is broadly accessible to compliance staff. Keeping them separate enforces the access restriction.
What goes in the DIHF?
All responses from prior-employer inquiries under 49 CFR 391.23 — general safety performance, drug and alcohol testing history (per 49 CFR 40.25), accident records. Plus any later prior-employer documentation (litigation, insurance inquiries).
How long must I keep the DIHF?
3 years after the driver's separation per 49 CFR 391.53(c). Some carriers retain longer for litigation defense.
Can the DIHF be electronic?
Yes. Most modern compliance software (including FileFlo) maintains the DIHF as a separate electronic folder with access-control settings enforcing the 391.53(d) restrictions.
Who can access the DIHF?
Per 49 CFR 391.53(d): authorized employees of the motor carrier (typically safety, HR, and compliance staff), the driver (upon request), and DOT representatives (auditors, inspectors). General employees, dispatchers, and external parties cannot access the DIHF.
Cross-references: 49 CFR 391.23 · 49 CFR 391.51 · 49 CFR 40.25 · 49 CFR 382.401
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