GP2 Series veteran Stefano Coletti will move to IndyCar this year after signing on to partner Sebastien Bourdais at KV Racing Technology.
The Monegasque tested with the team at NOLA last month, and said that he was excited by the prospect of racing in the US.
"I've always wanted to race in IndyCar and live overseas," said Coletti. "It's a great championship and the competition is very high.
"When I tested at NOLA a few weeks ago there was a great atmosphere and the whole team really welcomed me, so I can't wait to get to Indianapolis and start to work with the #4 crew and get to know everyone better."
Team co-owner Jimmy Vasser admitted that Coletti faces a learning curve in adapting to IndyCar, particularly with regard to the ovals, but said he is confident that the 25-year-old will get up to pace.
"Stefano has shown that he can win at a very high level in GP2, and we were extremely impressed with his knowledge and feedback during the test at NOLA.
"There will be a learning curve, especially on the ovals, but I think everyone feels that Stefano is up to the task."
Coletti spent four years in GP2 with Coloni, Trident and Racing Engineering, picking up seven wins along the way. His highest championship placing was fifth, which he achieved in 2013.
He replaces Sebastian Saavedra alongside Bourdais at KVRT.
The team will test again at NOLA on March 14 to sample the Chevrolet aero kit for the first time before moving to Barber for the two-day open test on March 16 and 17.
2015 INDYCAR SERIES LINE-UP SO FAR
AJ FOYT RACING (Honda)
#14 Takuma Sato
#41 Jack Hawksworth
ANDRETTI AUTOSPORT (Honda)
#25 Marco Andretti
#28 Ryan Hunter-Reay
#34 Carlos Munoz
BRYAN HERTA AUTOSPORT (Honda)
#98 Gabby Chaves
CFH RACING (Chevy)
#20 Ed Carpenter and Luca Filippi
#67 Josef Newgarden
CHIP GANASSI RACING (Chevy)
#8 Sage Karam (St Pete only at present)
#9 Scott Dixon
#10 Tony Kanaan
#83 Charlie Kimball
DALE COYNE RACING (Honda)
FAN FORCE UNITED (TBA)
#5 Stefan Wilson
KV RACING TECHNOLOGY (Chevy)
#4 Stefano Coletti
#11 Sebastien Bourdais
RAHAL LETTERMAN LANIGAN RACING (Honda)
#15 Graham Rahal
SCHMIDT PETERSON MOTORSPORT (Honda)
#7 James Jakes
#77 James Hinchcliffe
TEAM PENSKE (Chevy)
#1 Will Power
#2 Juan Pablo Montoya
#3 Helio Castroneves
#22 Simon Pagenaud