Here is a good write up on CARB, ZEV and SMILE states. It explains the difference.
What are CARB states, ZEV states and 'smile' states? Autoweek explains
https://autoweek.com/article/green-cars/autoweek-explains-carb-states-zev-states-smile-states
.......For example, the
Kia Niro EV I just drove is only for sale in ZEV states; Michigan is NOT a ZEV state, so if you want one here in Michigan, you’re out of luck. More about ZEV in a moment.
Let’s start with
CARB states. CARB stands for California Air Resources Board, a statewide “clean air agency” that enforces even stricter emissions laws than the federal
Environmental Protection Agency. ........ California is the only state permitted to issue emission standards subject to a waiver from the EPA.
Other states can and have joined CARB, including Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont, Washington state and Washington D.C. Basically, their emissions standards are stricter than federal requirements,
ZEV states are a little different, though there is frequently some overlap. ZEV means "zero emissions vehicle," and the ZEV states are the ones that have regulations requiring automakers to sell a certain volume of electric cars and trucks. CARB manages the ZEV program, which has now been adopted by Connecticut, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, Rhode Island and Vermont.
The program gives each automaker ZEV credits, and they are required to maintain them equal to a percentage of nonelectric vehicle sales. Each car sold earns credits based on the type of ZEV and its battery range. For example, in 2018 automakers needed about 2.5 percent of sales to be ZEVs; it goes up to 8 percent in 2025.
Plug-in hybrids count only account for 55 percent of those; battery electric vehicles and fuel cells must account for the remaining 45 percent.
.........
"Smile" states are a different story. ..........
In automotive terms, these states are where car companies can sell a lot of rear-wheel-drive cars, convertibles, etc. These states have around 300 days of sun and warm weather, meaning your 4Matics, SH-AWDs, xDrives and 4Motions aren’t really needed.