Andretti's Formula E cars are currently powered by BMW, but with the German manufacturer stepping away from the championship, intrigue had surrounded who the team would align with for the 2022/23 season.
That matter has now been cleared up with the announcement of “a long-term agreement”.
“Our Formula E journey began with Season 1 and we're very proud to now be looking ahead to the next generation of the sport,” said Michael Andretti.
“Avalanche Andretti FE has an ambition to win, and with the support of Porsche, we have full confidence in our performance and growth.
“The agreement is an important step in our future and commitment to our sport, partners, and fans.
“Our history with Porsche as two historic racing teams means this collaboration was a natural fit, and we look forward to a new chapter starting in 2023.”
There is history between Porsche and the Andrettis, as noted by Porsche Motorsport vice-president Thomas Laudenbach.
“Porsche and Andretti are united by a long tradition, and it all started when Mario and Michael made their Le Mans debuts in a Porsche 956 in 1983,” said Laudenbach.
“We're delighted that the tradition is continuing in Formula E, and we hope our partnership will be just as successful.
He added, “It's important for us to support a customer team that demonstrates the same passion and professionalism in Formula E as we do.
“Avalanche Andretti has raced in Formula E since the inaugural 2014 season.
“For us, it's a huge vote of confidence that one of the most experienced teams has chosen to work alongside Porsche from Season 9 onwards and wants to field two Porsche 99X Electric racers.”
It's the second big manufacturer switch for an Andretti race team in the space of eight days, the Supercars squad it's a partner in (Walkinshaw Andretti United) announcing a move to Ford for 2023.