What 390.21TE means in plain language
390.21TE falls under vehicle marking and identification requirements. This regulation requires certain text, numbers, or identifying information to be displayed on your truck in a specific format or location. The "TE" suffix typically refers to a particular type of marking deficiency—often related to how that information is presented, positioned, or legible to inspectors and the public.
The regulation is administrative in nature. It's not about your brakes, tires, or safety systems. It's about whether your truck displays the required markings correctly. This could mean lettering that's worn, faded, missing, incorrectly sized, or positioned in a way that doesn't meet the standard.
If you were cited, an inspector found that your truck's marking didn't meet the specification. The citation itself doesn't shut you down immediately—and that's important to understand.
What our enforcement data actually shows
Across 13 million inspections in our database, 390.21TE is cited relatively infrequently. We've recorded 478 all-time citations for this code, with 181 citations in the last 12 months and 30 in the last 90 days. That puts 390.21TE at rank #938 of 3,036 FMCSR codes by citation volume.
Here's the critical number: our data shows only 2 out-of-service placements across all 478 citations on record, for a 0.4% OOS rate. To put that in perspective, the average OOS rate across all FMCSR codes is 31.4%. This code is 78 percentage points below the national average. In plain terms: inspectors almost never remove a truck from service for a 390.21TE citation. You will not lose your truck.
In the last 12 months, we've seen 181 citations with zero out-of-service placements. In the last 90 days, 30 citations and still zero OOS events. The monthly trend over the past year shows citations ranging from 9 to 27 per month, but the pattern is consistent: citations are issued, but trucks stay in operation.
Who gets cited most
Our data from the last 180 days shows Texas leading by a significant margin, with 49 citations and a 0.0% OOS rate. Iowa follows with 17 citations and 0.0% OOS. Illinois has 2 citations, also 0.0% OOS.
The concentration in Texas and Iowa is notable, but the OOS rates are uniform across all three states—none of them resulted in a truck being pulled from service. This suggests the violation is being cited consistently across regions, but enforcement severity is stable nationwide.
Looking at carrier data, our records show fleets such as Coastal Tide Services LLC (USDOT 4219268) with 6 all-time citations for this code. U.S. Transportation LLC, Federal Express Corporation, Kovu Trucking LLC, Ztex Construction Inc, and Ean Holdings LLC each have 3 citations. This pattern reflects the fact that marking violations can happen to any carrier—they're widespread and not indicative of systemic negligence in any particular fleet.
How severe is this compared to similar codes
In the same category as 390.21TE, there are several peer codes that help contextualize severity. The largest by volume is 390.21TB2-DOT with 74,663 citations and a 0.0% OOS rate. 390.21T(b) has 61,097 citations at 0.0% OOS. 390.21TB1-MC shows 59,189 citations at 0.0% OOS.
All of these are marking-related codes in the same regulatory family. What's striking is that none of them have meaningful OOS rates. Even 390.19B2-BIENNIAL, which has 16,142 citations, sits at just 0.2% OOS. The pattern is clear: marking violations are cited frequently across the industry, but they're treated as administrative deficiencies, not safety threats. Your citation is consistent with how these codes are enforced nationwide.
How to avoid it
Based on patterns in our data, here are concrete steps to avoid a 390.21TE citation:
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Walk around your truck before every shift. Look for lettering, numbers, or decals that are faded, peeling, worn, or illegible. Pay special attention to the sides and back of the cab, where DOT numbers and company markings are typically displayed. If you can't read it from 10 feet away, an inspector won't be able to either.
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Check that all required text is in the correct position. Marking requirements specify size, font, contrast, and placement. If a decal has shifted during washing or impact, reposition it. If lettering is partially obscured—by mud, a cargo door, or a newly added sticker—clean it or remove the obstruction.
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Inspect after any accident or damage. If your truck has been bumped, hit, or had weather damage, walk the perimeter and verify all markings are intact and readable. Our data shows marking violations often cluster with other defects (we see 393.9, lighting issues, co-occurring frequently), so after damage, a full visual inspection is prudent.
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Schedule a professional cleaning or detailing if markings are faded. Weathered lettering and faded decals are common reasons for citation. If your truck has been on the road for years without repainting or refreshing decals, it's a low-cost preventive step.
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Don't rely on memory for placement rules. If you're unsure whether a marking is in the right spot or sized correctly, consult your company's documentation or the relevant FMCSR guidance. A 10-minute compliance check costs far less than a citation.
These are driver-level actions you can take before or during a pre-trip walk-around. They don't require special tools or expertise—just attention and regular observation.