By Evan Reid, Founder of Haul Handbook · Updated Sep 27, 2026
Massachusetts tests heavy diesel trucks for smoke as part of the annual state inspection every Massachusetts-registered commercial vehicle already needs. A diesel over 10,000 pounds GVWR, model year 1984 or newer, that has no OBD system gets a snap-acceleration opacity test at a licensed commercial inspection station, and one that has OBD gets an OBD test instead. Out-of-state heavy diesels are subject to emissions testing at roadside inspections. The enforcement is the registration: a failed truck that is not fixed and passed within 60 days has its Massachusetts registration suspended, and no waiver from the opacity standard exists for these trucks.
The program at a glance
- Program
- Massachusetts Vehicle Check, Massachusetts Motor Vehicle Emissions Inspection and Maintenance Program (heavy diesel opacity testing within the annual commercial motor vehicle inspection, plus roadside testing)
- Agency
- Massachusetts Department of Environmental Protection (MassDEP), which writes the emissions standards in 310 CMR 60.02, and the Massachusetts Registry of Motor Vehicles, which licenses the inspection stations and inspectors under 540 CMR 4.00 and suspends registrations; the two run Massachusetts Vehicle Check jointly
- Covered vehicles
- Diesel vehicles with a GVWR greater than 10,000 pounds. Those registered in Massachusetts take the emissions inspection every time they are submitted for their annual motor vehicle inspection. 310 CMR 60.02(3)(a) also brings diesel vehicles over 10,000 pounds operating on Commonwealth roads but not registered in Massachusetts into the program, and 60.02(5)(f) makes every diesel over 10,000 pounds operating on Massachusetts roads subject to emissions testing during roadside inspections, with the same standards applied. Exempt: any diesel vehicle with a model year earlier than 1984. Among covered trucks, the ones equipped with an OBD system take an OBD test; the ones without OBD take the SAE J1667 opacity test. MassDEP may exempt an out-of-state truck from roadside emissions testing if it has been tested in another state or jurisdiction.
- Legal basis
- 310 CMR 60.02, the Massachusetts Motor Vehicle Emissions Inspection and Maintenance Program, is promulgated by MassDEP under M.G.L. c. 111, s. 142M and c. 21A, ss. 2(28) and 16. It sets who is tested (60.02(3)), when (60.02(5)), which test applies (60.02(8)), the opacity cutpoints (60.02(12), Table A), the 60-day reinspection deadline and registration suspension (60.02(14)(d)), and the bar on opacity waivers for heavy diesels (60.02(17)(g)). The Registry's side is 540 CMR 4.00, Annual Safety and Combined Safety and Emissions Inspection, which licenses the stations that test commercial vehicles over 10,000 pounds and, at 540 CMR 4.07(4), suspends the registration of a vehicle that fails to meet the requirements or obtain a waiver.
Where the test happens and what it costs
- Where you register
- portal_name and portal_url are null on purpose. Massachusetts runs no carrier registration or reporting system for heavy diesel emissions; a carrier opens no account and reports no fleet. The test result is recorded by the licensed inspection station at the time of the inspection. The state publishes a station locator for finding a commercial inspection station.
- What compliance takes
- There is nothing to enroll in. The opacity or OBD test is part of the annual Massachusetts commercial motor vehicle inspection at a licensed inspection station, due by the last day of the month on the previous inspection sticker. Not every station tests commercial vehicles: under 540 CMR 4.02 a Class C, D or E station license covers heavy commercial inspections, and fleets can use mobile inspectors who bring testing equipment to the company lot or a licensed company employee. The Massachusetts commercial inspection is accepted as equivalent to the annual FMCSA DOT inspection, so one visit covers state safety, state emissions and the federal annual inspection.
- Inspection fee
- $35 (State base fee for the annual Commercial Motor Vehicle Inspection, which carries the emissions test; the station adds its own posted labor charge for the commercial inspection, so the total varies by station. The emissions test is not priced separately, and one free reinspection is allowed within 60 calendar days at the station that failed the truck. No separate 2027 figure is published; the base has been in the Massachusetts Vehicle Check fee table since July 1, 2014 and matches the RMV Schedule of Fees (Commercial Vehicle Inspection, plus market labor rate).)
- Testing cadence
- Annual, with the safety inspection. A Massachusetts-registered heavy diesel takes its emissions test every time it is submitted for its annual motor vehicle inspection, no later than the last day of the month and year on the previous inspection sticker. Roadside emissions testing is separate and unscheduled, and reaches out-of-state trucks as well. A truck operating outside Massachusetts when its sticker expires must file an Out-of-State Verification Inspection Form with proof of that state's inspection, or the RMV automatically suspends the registration.
- Test methods
- Two tests, chosen by equipment. A heavy diesel equipped with an OBD system takes the on-board diagnostics test. A model year 1984 or newer diesel over 10,000 pounds GVWR without OBD takes the SAE J1667 snap-acceleration opacity test: the inspector reads the exhaust with an opacity (smoke) meter over three acceleration snaps, averages the readings, and compares the average with the cutpoint for the vehicle's model year and type.
- Registration holds
- Yes, through suspension. Under 310 CMR 60.02(14)(d), unless a vehicle that failed its emissions inspection passes a reinspection within 60 days, obtains a waiver, or obtains an economic hardship failure repair extension, it may not be operated on a public road and its Massachusetts registration is suspended under 540 CMR 4.00. A heavy diesel cannot get a waiver from the opacity standards. 540 CMR 4.07(4) states that failing to meet the inspection requirements or obtain a waiver results in suspension of the registration.
- Roadside authority
- 310 CMR 60.02(5)(f) subjects every diesel vehicle over 10,000 pounds GVWR operating on Massachusetts roads to emissions testing during roadside inspections, and applies the same emissions standards there. MassDEP may exempt a vehicle tested in another state or jurisdiction from roadside emissions inspection.
The state publishes a map of licensed inspection facilities at the official facility locator.
Opacity cutpoints by engine model year
Opacity is the share of light the exhaust blocks. An older engine gets a looser number because the cutpoints were written around the technology of its build year, so a truck that passed last decade on a 40 percent limit is held to a tighter one once it is replaced.
Scroll sideways to see every column.
Table A of 310 CMR 60.02(12)(a), Opacity Test Cutpoints. The model years in the regulation are the vehicle's model years. Opacity is the percentage of light the exhaust blocks, so darker smoke reads higher. 310 CMR 60.02(17)(g) makes diesel vehicles over 10,000 pounds GVWR ineligible for a waiver from the opacity standards: a failing truck has to be repaired until it passes.
Who the program covers
The MassDEP regulation reaches diesel vehicles above the heavy weight line in two ways. A truck registered in Massachusetts takes an emissions test every time it goes in for its annual state inspection. A heavy diesel operating on Massachusetts roads but registered somewhere else is covered too, through emissions testing at roadside inspections, with the same standards applied; MassDEP may excuse a truck already tested in another jurisdiction.
Diesels built before the regulation's cutoff model year are exempt. Among covered trucks, the equipment decides the test: a truck with an OBD system takes the OBD test, and one without takes the opacity test.
Where the test happens, and what it costs
There is no portal and nothing to enroll in. The test is part of the Massachusetts commercial motor vehicle inspection at a licensed station, due by the end of the month shown on the last sticker. Not every station handles heavy trucks, so use the state's station locator to find a commercial inspection station, or, for a fleet, a mobile inspector who brings the equipment to the company lot. The same visit counts as the annual federal DOT inspection.
The state sets a base inspection fee, and the station adds its own posted labor charge for the commercial inspection, so the total varies by shop. The emissions test carries no separate charge, and a failed truck gets one free reinspection at the same station within the reinspection window.
The opacity test and the cutpoints
The opacity test follows the SAE J1667 snap-acceleration procedure. The inspector reads the exhaust with a smoke meter over three acceleration snaps, averages the readings, and compares the average with the cutpoint for the truck's model year and type. Darker smoke reads higher.
The cutpoints step down in three model-year tiers for trucks and three for buses, so newer engines are held to a tighter number. The sourced table carries every tier from the regulation.
What failing costs
Massachusetts enforces this program through the registration, not a ticket schedule. A truck that fails has a set number of days to be repaired and pass a reinspection. Miss that window and the truck may not run on a public road, and its registration is suspended under the Registry's inspection regulation.
There is no escape hatch for heavy diesels. Lighter vehicles can apply for a waiver after qualifying repairs, but diesel trucks over the weight line are not eligible for a waiver from the opacity standards, so the only way out is a truck that passes. A truck operating out of state when its sticker runs out needs an out-of-state verification form on file, or the RMV suspends the registration automatically.
What this page does not cover
This is a Massachusetts program, not a copy of California's or New Jersey's. There is no reporting database and no separate emissions fee, as in New Jersey, but unlike New Jersey the test sits inside the annual state safety inspection at the same station, and the enforcement is registration suspension rather than a statutory ticket schedule. No dollar penalty for a failed or missed heavy diesel emissions inspection was found on the MassDEP or RMV sources read, and none is recorded. Driving without a valid inspection sticker is a traffic violation that the RMV says may bring a fine and affect insurance rates, without stating an amount. Idling and the Advanced Clean Trucks sales rules are separate programs and are not part of this file.
Where the inspection fits in the Massachusetts stack
The inspection deadline rides on the registration date, so it belongs on the same calendar as the credentials in start a trucking company in Massachusetts and the apportioned renewal in Massachusetts IRP registration. The rest of the state permit picture lives in Massachusetts trucking permits.