Currently, Hyundai sells its plug-in hybrid Sonata nationwide, though it doesn't necessarily seem that way due to the fact that, in most states, dealers aren't required to actually stock the Sonata PHEV (although they do have the option to do so). Rather, it's available via special order item available through your local dealer.
Hyundai IONIQ Plug-in
Only dealerships in 10 states (California and those other states that share California emissions standard) routinely stock the Sonata PHEV.
In the other 40 states (for the most part), you simply have walk into a Hyundai dealerships and place your Sonata PHEV order. Then, you wait a few weeks to take delivery. It's not an ideal setup, but at least it is available nationwide, something that can't be said for a dozen other plug-ins on the US market today.
According to Hyundai, the same process will be in place for the plug-in hybrid version of IONIQ (32 miles of EPA-estimated electric range).
While the hybrid version of IONIQ will be readily available at dealerships across the nation, the BEV in limited CARB states, the PHEV version will again be stocked at dealerships in only 10 states and available for special order in the remaining 40 states.
We don't love this arrangement, but as mentioned above, at least Hyundai is making the plug-in hybrid IONIQ available nationwide, which can't be said of a lot of the other plug-ins on the market today.
Before the IONIQ PHEV hits the U.S. market, both the BEV (coming in Q1 2017 and deemed the U.S.' most fuel-efficient vehicle ever sold) and conventional hybrid versions will launch. We expect to see the PHEV IONIQ go on sale in the U.S. in mid 2017, likely as a 2018 model year offering.
Hyundai IONIQ Lineup Release schedule for US (as at Jan/12/2017) ... sad faces for the plug-in hybrid model
Source: Green Car Reports