49 CFR § 391.53
Driver investigation history file
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What does 49 CFR § 391.53 require?
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 text (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).
Read full regulation at eCFR.govWho must comply with 49 CFR § 391.53?
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 you violate 49 CFR § 391.53?
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.
Penalty range
Annual citations
YoY penalty trend
How to comply (implementation checklist)
- 1Create a DIHF for every driver SEPARATE from the DQF (electronic folder or paper file).
- 2Document all prior-employer inquiries under 49 CFR 391.23 in the DIHF.
- 3Retain prior-employer responses (whether responsive or non-responsive) in the DIHF.
- 4Restrict DIHF access to authorized employees, the driver, and DOT representatives per 49 CFR 391.53(d).
- 5Train HR and safety staff on the DIHF vs DQF separation requirement.
- 6Retain the DIHF for 3 years after the driver's separation per 49 CFR 391.53(c).
- 7For electronic DIHFs, use access controls to enforce the restricted-access requirement.
- 8Audit 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).
Real enforcement examples
Anonymized from public FMCSA enforcement summaries. Penalty amounts reflect assessed and final settled values where disclosed.
Mid-size carrier received $35,200 penalty in 2024 after Compliance Review found no separate DIHFs — all prior-employer responses had been filed in the DQF. Auditor cited 49 CFR 391.53 violations across the fleet.
Source: FMCSA SafetyNet 2024 enforcement summary, anonymized
How FileFlo handles 49 CFR § 391.53
FileFlo's compliance rule-pack DQF-49CFR391.53 automatically checks every document you upload against this regulation. Auto-detects document type, parses key fields, sets renewal alerts, and surfaces this section in your audit binder if a gap is found.
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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.
Related regulations
Related guides
Sources + reviewer
Primary source: eCFR.gov: 49 CFR § 391.53
Reviewed by Chad Griffith (Founder + CEO, FileFlo) on