Cadillac spokesman David Caldwell confirmed the launch timetable for Edmunds, but said pricing is not available yet.
Cadillac's first plug-in hybrid will follow the non-hybrid 2016 Cadillac CT6. The all-new flagship sedan goes into production in the U.S. in December and is expected to make its showroom debut early next year.
The CT6 Plug-in Hybrid will feature a 2.0-liter turbocharged four-cylinder engine, two electric motors and an 18.4 kilowatt-hour lithium-ion battery pack, delivering an estimated 335 horsepower and 432 pound-feet of torque.
Cadillac said range estimates will be provided closer to the U.S. launch, but the car is expected to be able to go farther than 37 miles on electric power alone, according to Automotive News.
"The system is designed to provide all-electric driving for most daily commutes," said GM in a statement.
The plug-in hybrid system is expected to more than double the fuel economy of the conventional powertrain offerings in the CT6. The EPA has not posted official fuel economy numbers on any version of the new CT6.
The 2015 Mercedes-Benz S-Class Plug-in Hybrid is the key competition to the CT6 Plug-in Hybrid.
Edmunds says: Efficiency is a new element of luxury in the high-end sedan class, and Cadillac is looking to offer something most of its competitors can't with the CT6 Hybrid.