A new program will give many Colorado residents up to $6,000 to help them trade in an older gas-powered car in exchange for a new electric vehicle (EV) or plug-in hybrid (PHEV), or $4,000 to help buy a used EV or PHEV.

The Vehicle Exchange Colorado program opens today. Residents can apply through the state Department of Energy website.

Related – Electric Car Rebates and Incentives: What to Know by State

The buyer and the trade-in must meet specific requirements to qualify for the funds.

The money is provided as a rebate at the point of sale.

To qualify, residents must earn below 80% of the median income in their county for a household of their size. That means the eligibility criteria change from county to county. Single Boulder County residents can qualify with an income of up to $74,400. Single residents in Yuma County can only make up to $48,720.

Trade-in cars must be at least 12 years old or have failed an emissions inspection. That requirement, the state’s energy department says, ensures that the program helps improve Colorado’s air quality.

The new car’s total cost must be $50,000 or less after applying other credits, including the $7,500 federal EV tax credit. “Add-ons, upgrades, [and] destination charges” do not count toward that total. Leased vehicles are eligible.

Manufacturers must have a brick-and-mortar location in Colorado for their cars to qualify. Several EV-only automakers that don’t maintain stores in every state have a location in Colorado, including Tesla, Rivian, and Lucid.