A base $2500 credit accrues to electrified vehicles, which are EVs or plug-in hybrids, not regular hybrids. Vehicles that are “propelled to a significant extent by an electric motor”—defined as having battery-pack capacities of at least 5 kilowatt-hours—qualify for an additional $417, plus $417 for each 1-kWh increase in battery capacity, up to a maximum of $7500 per vehicle. So, for example, a car with a 6-kWh battery pack would earn $2500 as a base amount, an additional $417 for meeting the 5-kWh threshold, and another $417 for surpassing that threshold by 1 kWh; total credit: $3334. But don’t worry, you’re not required to do the math. The IRS does it for you, with a breakdown of the credit for each make and model here. The Phase-Out
The government’s offer of a tax credit is intended to expire eventually. That will happen at a different time for each automaker, with a phase-out period beginning once each manufacturer hits 200,000 plug-in vehicles sold. By some estimates, including a recent projection, Tesla and General Motors will get there first, in 2018, with Nissan likely to hit that number in 2019.