How we make rules

What is a rule?

A rule, or Washington Administrative Code (WAC), is an agency regulation that:

• Requires penalties for people who violate the rule.
• Creates, changes, or removes any privilege.
• Sets procedures or requirements for agency hearings.
• Sets requirements for benefits that the law gives.
• Sets standards for issuing, suspending, or revoking business and professional licenses.
• Sets requirements for products and materials that will be sold or given.

What are the types of rules?

There are 3 types of rules: interpretive rules, procedural rules, and significant legislative rules.

Interpretive rules

Interpretive rules describe how we interpret the laws we're responsible for. These rules don't require penalties for people who violate them.

Procedural rules

Procedural rules adopt, amend, or repeal any:

• Procedures or requirements for agency hearings.
• Requirements about ways to apply for a license or permit.
• Policies about our internal operations.

Significant legislative rules

Significant legislative rules:

• Adopt major parts of a law within our authority, and require penalties for people who violate the rule.
• Create, change, or remove requirements for issuing, suspending, or revoking a license or permit.
• Adopt new policies or regulations.
• Make major changes to policies or regulations.

What is rulemaking?

Rulemaking is how we create and adopt rules. There are 3 steps in the rulemaking process. See explanations for each step below.

1. Preproposal statement of inquiry (CR-101)

Before we propose a rule, we invite the public to discuss the possible rulemaking with us.

2. Proposed rulemaking (CR-102)

When we propose a rule, we notify the public that:

• We're considering a new rule,
• We made significant changes to a rule that we already filed, or
• We need to delay a rule proceeding that already started

We also tell the public:

• The date of the public hearing about the proposed rule.
• How to comment on the proposed rule.

3. Adopted rulemaking order (CR-103)

After approving the rule, we file it with the Office of the Code Reviser (OCR) to put it into effect.

Normally, a rule goes into effect 31 days after we file it. Sometimes, we'll choose a later date to put it into effect.

Other rulemaking steps

In some cases, we may use different steps for adopting or changing a rule. These include:

• Emergency rules
• Expedited rulemaking (CR-105)

We can only use these for specific reasons. See our definitions for rules to learn more about these steps.

What are the goals of rulemaking?

The rulemaking process allows us to:

• Say how we interpret the law.
• Write understandable rules.
• Notify the public when we plan to propose rules.
• Encourage the public to participate in rulemaking.
• Adopt rules that are technically accurate.
• Adopt rules that aren't excessive, unreasonable, or unnecessary.

Licensing interpretive statements

We notify the public of our current opinions, approaches, and likely course of action through licensing interpretive statements. These statements are authorized by law and clarify how we manage taxes and fees from:

• Vehicles and boats
• Drivers and ID cards
• Business and professions
• Prorate and fuel tax

Current licensing interpretive statements

2026-01: Temporary Pause of the Advanced Clean Cars and Trucks Emission Standards for Vehicle Registration

Purpose

This Vehicle/Vessel Advisory addresses the application of vehicle registration under Chapter 46.16A RCW.

This advisory notice explains the Department of Licensing’s temporary process change for registering light-duty, medium-duty, and heavy-duty vehicles that might not meet certain California emissions standards. This process change will remain in effect for as long as the Washington State Department of Ecology’s pause on vehicle emissions rules are in place.

Authority

The Department of Licensing is responsible for administering vehicle registration under Chapter 46.16A RCW. RCW 46.16A.060(5) requires vehicle registration standards to align with standards set forth by the Department of Ecology and California emissions adopted in this state.

Registration requirement changes

New vehicles sold and registered in Washington must meet certain emissions standards set forth by the Department of Ecology (RCW 46.16A.060 and Chapter 70A.30 RCW). These standards align with California’s emissions standards. Vehicles that do not meet these standards generally cannot be registered in Washington, unless they qualify for an exemption.

A temporary pause will be in effect, allowing heavy-duty trucks with a model year of 2025 or newer to be registered. Additionally, all light-duty and medium-duty vehicles with a model year of 2026 or newer can be registered -- even if their Manufacturer’s Certificate of Origin (MCO) or Manufacturer’s Statement of Origin (MSO) says they cannot be sold or registered in Washington or California.

Information on whether a new vehicle meets California and Washington’s emissions standards can be found on a new vehicle’s MSO, MCO, or a vehicle’s window sticker.

The following are example MSO/MCO statements that would normally not allow a vehicle to be registered:

• “This vehicle meets/satisfies federal emission standards.”
• “This vehicle is certified/legal for sale in 49 states.”
• “This vehicle is certified/legal for sale in 45 states.”
• “This vehicle has a federal emissions system.”
• “This vehicle does not comply with California motor vehicle emissions requirements.”

During this regulatory pause, some vehicles with these statements may still qualify for registration, depending on their class types. A vehicle’s class type is based on its Gross Vehicle Weight Rating (GVWR).

Recent federal actions

The Clean Air Act allows California to seek a waiver of the preemption which prohibits states from enacting emission standards for new motor vehicles.

On June 12, 2025, three Congressional Review Act (CRA) resolutions were signed by President Trump that nullify Environmental Protection Agency waivers granted to California:

• Advanced Clean Cars (87 FR 14332): Not included in or subject to the CRAs signed into law; EPA waiver has not been revoked. Ecology’s notice indicated the Advanced Clear Car provisions will remain effect. There will be no changes to vehicle registrations under the Advanced Clean Cars standards, which cover model year 2025 light and medium-duty passenger vehicles.
• Advanced Clean Cars II (90 FR 642): EPA waiver was attempted to be revoked by House Joint Resolution 88¹. Ecology’s guidance on Advanced Clean Cars II impacts light-duty zero emission vehicle and low emissions vehicles standards for model years 2026 and after.
• Advanced Clean Trucks (88 FR 20688): EPA waiver was attempted to be revoked by House Joint Resolution 87². Ecology’s guidance on Advanced Clean Trucks impacts all heavy duty zero emission on-road vehicles for model years 2025 that are not currently eligible for registration in Washington.
• Heavy-Duty Low NOx Omnibus (90 FR 643): EPA waiver has been revoked by House Joint Resolution 89. This will impact registration requirements for Heavy Duty Internal Combustion Engine vehicles that are not currently eligible for registration in Washington.

Clean Air Act Washington standards

The Clean Air Act allows Washington to adopt California’s motor vehicle emission standards under section 177 (42 U.S.C. Sec. 7507). Chapter 70A.30 RCW regulates the motor vehicle emissions for Washington State. The Department of Licensing may not register a vehicle that does not meet the requirements of CA emission standards adopted by the Department of Ecology. RCW 46.16A.060(5).

On June 6, 2025, the Department of Ecology sent a regulatory guidance notice to light-duty, medium- and heavy-duty vehicle manufacturers titled “Regulatory Guidance for Advanced Clean Cars II, Advanced Clean Trucks, and Heavy-Duty Low NOx Omnibus.”

This notice provides a pause for two California emissions standards (Advanced Clean Cars II and Advanced Clean Trucks), pauses the third standard for model years 2026 (Heavy-Duty Low NOx Omnibus), and clarifies the Advanced Clean Cars standard is still in effect. The pause for Heavy-Duty Low NOx Omnibus ends after December 31, 2026. Ecology will issue additional guidance as needed.

Vehicle Classifications

In coordination with the Department of Ecology’s June 6, 2025, guidance, this notice details the registration changes made in response to federal and Ecology action. While Ecology’s policy guidance is in place, the following vehicle classes are eligible for registration:

• Light and medium-duty vehicles with a model year of 2025 or newer.
  • Light-duty vehicles have a GVWR of 8,500 lbs. or less.
  • Medium-duty vehicles have a GVWR of 14,000 lbs. or less.
  • This includes lighter vehicles such as passenger cars, pickup trucks, vans, Class 2b-3 commercial vehicles, and SUVs.
• Heavy-duty vehicles with a model year of 2025 or newer.
  • These vehicles have a GVWR of 14,001 lbs. or more.
  • This includes larger commercial trucks such as Class 4-6 trucks, Class 7 and 8, semi-trucks, refuse trucks, motorcoaches, and school buses.
  • Internal combustion engine heavy-duty vehicles that would be subject to the Heavy-Duty Low NOx Omnibus in model year 2026 are additionally eligible for registration through December 31, 2026.

Notes

1. The federal government has taken action to revoke this waiver. This action is currently being disputed in federal court.
2. Similarly to the Advanced Clean Cars II waiver action, the federal revocation of this regulation is currently being disputed in federal court.

Previous licensing interpretive statements

Related laws

• The Administrative Procedures Act (APA) (RCW 34.05) (Chapters 1-21 WAC)
• The Regulatory Fairness Act (RCW 19.85)