General Motors Co. sold 200,000 electric vehicles in the U.S. by the end of 2018, which began the phaseout of a federal tax credit for consumers who purchase the company's model, according to Reuters, citing a person familiar with the matter.

The Detroit-based automaker told S&P Global Market Intelligence in November that it expected to reach 200,000 in EV sales by the end of the year, and on Jan. 2, Reuters reported that GM hit the number.

A GM spokesperson said in an email the company has not confirmed its 2018 sales numbers but expects to release those numbers Jan 3.

The phaseout of the federal electric-vehicle tax credit for GM consumers means those who purchase GM's electric cars will have until April to redeem the full $7,500 credit before it drops to $3,750, Reuters reported. The credit will fall to $1,875 in October before ending in April 2020.

GM is the second U.S. automaker to hit the 200,000 EV threshold, following Tesla Inc., which reached that mark in July.

According to numbers compiled by electric-car news site Inside EVs, the next in line is Japanese automaker Nissan Motor Co. Ltd., which sold approximately 124,513 EVs as of Sept. 30.

The future of the U.S. federal EV tax credit is uncertain as carmakers fight to extend tax breaks and some lawmakers work to dismantle it. Under the current law, once an automaker sells 200,000 EVs, consumers can receive 50% of the full $7,500 credit during the first two quarters after the cap was reached, followed by 25% of the credit in the third and fourth quarters. After that, the credit is no longer available.