The short answer: a DOT safety rating is an official safety fitness determination under 49 CFR Part 385 with three values: Satisfactory, Conditional, Unsatisfactory. It is assigned only after a compliance review, it never expires, and Unsatisfactory takes away your right to operate. A CSA score is a BASIC percentile recalculated monthly by FMCSA's Safety Measurement System. It is not a rating, and by statute it cannot be used to determine safety fitness. Having CSA data and no rating at all is normal for most carriers.
Confusing the two costs money both ways: owners panic over a percentile that by itself cannot touch their authority, then shrug off a Conditional rating that stays on the record indefinitely. For the CSA side on its own, start with our CSA Scores Explained guide.
It is FMCSA's formal answer to one question: does this carrier have adequate safety management controls? The answers are defined in 49 CFR 385.3:
A rating is issued within 30 days after a compliance review (385.9). A safety audit is not a compliance review: 385.3 says safety audits do not result in safety ratings, which is why a new entrant who passed still shows no rating. And a rating has no expiry date. It stands until a later review replaces it, which is why a Conditional from four years ago is still visible in the carrier's public record today.
CSA is the enforcement program; SMS is the machine inside it. SMS sorts inspection results and crash reports into seven BASICs and produces a measure plus a percentile ranking you against carriers with a similar amount of safety data, refreshed on a roughly monthly snapshot over a rolling 24-month window. FMCSA itself warns on the SMS site that readers "should not draw conclusions about a carrier's overall safety condition" from that data, and that its prioritization symbol implies no federal safety rating under 49 U.S.C. 31144. There is also a statutory wall: section 5223 of the FAST Act (2015) bars FMCSA from using SMS percentiles and alerts in safety fitness determinations until the DOT Inspector General issues five certifications, and the agency confirmed in 2023 that they have not been issued. Thresholds are covered in our guide to good and bad CSA thresholds.
| Question | DOT Safety Rating | CSA BASIC Percentile |
|---|---|---|
| What is it legally? | Safety fitness determination under 49 CFR Part 385 | Prioritization metric. Not a rating, not a fitness determination |
| Who assigns it | FMCSA, after human review by an investigator | Nobody. SMS computes it automatically |
| Based on what | Acute and critical violations found in your files, converted into points across five regulatory factors, plus a sixth Accident factor, under the Appendix B formula | Roadside inspections, reportable crashes, plus acute and critical violations found in investigations over the previous 12 months |
| Scale | 3 words: Satisfactory / Conditional / Unsatisfactory | 0 to 100 percentile in each of 7 BASICs |
| How often it updates | Only when a new review happens. It never expires | Monthly snapshot; events leave the 24-month window |
| Public visibility | Public for every rated carrier | Property carriers' percentiles hidden since the FAST Act; you see your own after login |
| Can it stop you operating? | Yes. Unsatisfactory brings an out-of-service order and revocation of authority (385.13) | No. Barred by FAST Act sec. 5223 from use in fitness determinations |
| Where to check it | SAFER, safer.fmcsa.dot.gov | SMS, ai.fmcsa.dot.gov/sms |
| How to challenge it | Administrative review (385.15) or corrective-action upgrade (385.17) | DataQ Request for Data Review, dataqs.fmcsa.dot.gov |
There is no third thing either. FMCSA publishes no blended "federal motor carrier safety score", and no "DOT safety rating score", because the rating is not a number. When someone says your safety score is bad, ask which system they read; often it is a private vendor's risk score, which is neither. See how brokers and shippers actually check your CSA.
| Rating | Keep operating? | Timeline in the rules | Real consequences |
|---|---|---|---|
| Satisfactory | Yes | Final on the date of the notice (385.11(b)) | The strongest credential in the industry, and a snapshot of the review date, not today |
| Conditional | Yes | Proposed rating becomes final after 60 days, or 45 days for passenger and placarded hazmat carriers (385.11(c)) | No federal prohibition, but public and permanent until upgraded. In practice many brokers and underwriters treat it as a risk flag |
| Unsatisfactory | No | Prohibited from operating a CMV from the 61st day after the proposed rating notice, or the 46th day for passenger and placarded hazmat carriers (385.13(a)) | Out-of-service order, revocation of operating authority (385.13(e)), and federal agencies may not use you (385.13(b), (c)) |
| Unrated | Yes | Not applicable | The default for most carriers. Neutral with FMCSA, occasionally a minus with conservative shippers |
One mercy is in the rule: under 385.13(a)(2) and 385.17(g), if FMCSA finds a non-hazmat, non-passenger carrier is making a good-faith effort to improve, it may allow up to 60 additional days beyond the initial 60, and that extra period starts on the 61st day after the date of the notice. No such extension exists for passenger or placarded hazmat carriers, and filing a request for change does not pause their 45-day clock (385.17(f)).
No. An investigator cites acute and critical violations found in your files, and a formula converts them into points across five regulatory factors: 1 point per acute violation, 1 point per pattern of critical violations, and 2 points for a Part 395 hours-of-service pattern, which is why HOS violations hurt more than anything. The rating is not the investigator's verdict: Appendix B says FMCSA developed a computerized rating formula and uses it to assign the rating, and the official rating is determined in Washington, D.C. Road data enters in two places, as raw statistics rather than rankings. The Vehicle factor starts at Conditional with a vehicle out-of-service rate of 34 percent or greater over three or more vehicle inspections in the prior 12 months, or three vehicles inspected during the review itself, or any combination totalling three. The sixth factor, Accident, is not scored from violations at all: it is your recordable accident rate, used only with two or more recordable accidents in those 12 months, and Unsatisfactory above 1.5 per million miles, or 1.7 within a 100 air-mile radius. Your BASIC percentile never enters the formula.
The traffic between the two systems runs one way only. The percentile does not feed the rating, but acute and critical violations found during an investigation do feed back into SMS: FMCSA's SMS methodology states that acute and critical violations discovered in investigations over the previous 12 months are used alongside inspection and crash data to set your prioritization status.
What CSA does control is attention: a percentile above an intervention threshold can bring a warning letter or an investigation, and if that investigation is a ratable compliance review, a rating appears. FMCSA once tried to merge the systems, proposing in the January 2016 NPRM titled "Carrier Safety Fitness Determination" (81 FR 3562) to issue fitness determinations from SMS data and replace the three ratings with a single "Unfit". It withdrew that on March 23, 2017, and in August 2023 opened a fresh advance notice of proposed rulemaking (docket FMCSA-2022-0003) asking whether the three-tier structure should survive. Nothing in Part 385 has changed as a result.
Because a rating exists only as the output of a compliance review, and FMCSA cannot review everyone. The agency published the arithmetic in that 2023 notice: in fiscal year 2019, FMCSA and its state partners conducted 11,671 compliance reviews across more than 567,000 active interstate motor carriers, producing 2,701 final Satisfactory ratings, 1,842 Conditional and 306 Unsatisfactory. Roughly 2 percent of carriers are touched in a year, so unrated is the statistical default, not a black mark.
Passing the new entrant safety audit gives you no rating either: you get written notice that your basic safety management controls are adequate, plus close monitoring for the rest of the 18-month new entrant period (385.319(b)). Failing is another matter: under 385.319(c) your registration is revoked and operations placed out of service unless you fix the listed items within 60 days, or 45 days for placarded hazmat and the passenger categories the rule names.
A compliance review is the only event that puts a word on your record, so it is the only one worth rehearsing. Our Mock DOT Audit costs $399: we run the Appendix B checklist against your real files, count acute and critical exposure factor by factor, and hand you the fix list before an investigator writes it for you. Ongoing Safety Compliance packages start at $99/mo, with CSA monitoring after every monthly SMS snapshot. Starting from scratch? The Authority Bundle is $499. Russian, English and Ukrainian.
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The rating is a fitness determination under Part 385 with three values, assigned after a compliance review. The CSA score is an automatic SMS percentile. Only the rating can revoke your authority.
No. FMCSA says its SMS prioritization symbol implies no federal safety rating, and FAST Act section 5223 bars using percentiles and alerts for fitness determinations.
Satisfactory, Conditional and Unsatisfactory, defined in 49 CFR 385.3. Having no rating is a separate status, unrated carrier, not a fourth grade.
You can still operate: 385.13 prohibits operation only for Unsatisfactory. Conditional is public and stays until upgraded, and in practice many brokers and underwriters treat it as a risk flag, though FMCSA imposes no operating restriction for it.
Because you have not had a compliance review. In FY2019 there were 11,671 reviews across 567,000+ active interstate carriers. A new entrant safety audit produces no rating.
SAFER, safer.fmcsa.dot.gov, per 385.13(a), or by phone at (800) 832-5660. CSA data is at ai.fmcsa.dot.gov/sms.
Not directly. A high percentile can put you in line for an investigation; the rating then comes from acute and critical violations in your files.
File under 385.17 to your FMCSA Service Center at any time, documenting corrective actions. FMCSA reviews Unsatisfactory cases within 30 or 45 days depending on cargo.