Does a Maine truck need a USDOT number for in-state work?

Yes, above 26,000 lb: Maine's rule exempts in-state trucks rated 10,000 to 26,000 lb that are not buses and carry no hazardous materials. A State Police FAQ gives a lower line, so check with them if your truck is in between.

Checked against Maine’s official sources in September 2026.

The rule in Maine

Who it covers: Common, contract and private carriers. The rule "applies to any interstate or intrastate common, contract, and private motor carrier that transports passengers or property in Maine" (16-222 CMR ch. 4 § 2).

The weight line: In-state-only trucks rated 10,000 to 26,000 lb that are not buses and carry no hazardous materials are exempt from the USDOT number and marking rules. Above 26,000 lb a USDOT number is required.

Exemptions the state lists:

Intrastate vehicles of 10,000-26,000 lb GVWR that are not buses and do not transport hazardous materials are exempt from 49 CFR 390.19 and 390.21, the USDOT number and marking rules (16-222 CMR ch. 4 § 4(B-1))

“Vehicles in excess of 26,000 pounds, even in intrastate commerce, must obtain or display a USDOT number from the FMCSA.” source

“Intrastate vehicles to which this chapter applies that have a gross vehicle weight rating of 10,000 lbs. to 26,000 lbs., and that neither meet the definition of a "bus" nor transport hazardous materials, are exempt from 49 C.F.R. §§ 390.19 and 390.21.” source

The rule: 16-222 C.M.R. ch. 4, §§ 3 and 4(B-1) (Maine Motor Carrier Safety Regulation, adopted under 29-A M.R.S. § 555(2)); see also 29-A M.R.S. § 555-A

Who to ask: Maine State Police, Commercial Vehicle Enforcement Unit (safety rules and the intrastate exemption); Bureau of Motor Vehicles, Motor Carrier Services

Safety rules for in-state trucks

The Maine State Police adopts 49 CFR Parts 40, 382, 390, 393 and 396, and most of Part 392, without amendment. It adopts Parts 383, 391 and 395 with state amendments for intrastate carriers. (16-222 C.M.R. ch. 4, §§ 3-4)

Intrastate carriers operating within 100 air miles of their regular place of business are exempt from the federal hours-of-service rules (Part 395).
Intrastate drivers operating beyond 100 air miles are exempt from the federal age-21 rule but must be at least 18.
Intrastate carriers operating within 100 air miles are subject to only a short list of the federal driver-qualification rules.

The federal lines, which apply in Maine too

10,001 lb and interstate commerce: a USDOT number, a medical card, a driver qualification file, the hours-of-service rules and daily inspections (49 CFR 390.5).
26,001 lb: a CDL, for a single vehicle or a combination towing more than 10,000 lb (383.5). The CDL rules cover in-state driving as well (383.3), and drug and alcohol testing follows the CDL (382.103).

Check your own truck and trailer

Questions

Does Maine require a USDOT number for intrastate trucks?

What is the CDL weight in Maine?

The same as everywhere: 26,001 lb for a single vehicle, or a combination of 26,001 lb towing more than 10,000 lb. The federal CDL rules apply to in-state driving too (49 CFR 383.3), and drug and alcohol testing follows the CDL (382.103).

Who administers the rule in Maine?

Maine State Police, Commercial Vehicle Enforcement Unit (safety rules and the intrastate exemption); Bureau of Motor Vehicles, Motor Carrier Services.

What we could not confirm

The sources conflict. A Maine State Police FAQ (dated 2019) says in-state vehicles need a USDOT number from 10,001 lb registered weight, or with three or more axles; the rule (amended 2015) and the Secretary of State exempt in-state trucks of 10,000 to 26,000 lb. This page follows the rule — ask the State Police if your truck is in between.
Whether the exemption uses the truck's rating only or the combination's too was not confirmed: the rule names the vehicle rating, the Secretary of State's page names both.

Sources

General information, not legal advice. It summarises Maine’s published rules as read in September 2026; confirm with the Maine State Police or FMCSA.