Michelle Kaufman of the Miami Herald reported Higuain's annual base salary will be around $7 million, which will make him MLS' highest-paid player.
The 32-year-old attacker has played for some of the biggest clubs in Europe. After starting his career with River Plate in Argentina, he joined Real Madrid in 2007 before stops with Napoli and Juventus. He also went on loan stints with A.C. Milan and Chelsea in recent years.
He told Inter Miami's official website he's excited to help set a standard for a club in its infancy.
"It excites me that this is a new club with ambition to grow and do things well," Higuain said. "It's a beautiful place to be able to play...I think there's a good team here to be able to do important things."
The striker's goal-scoring numbers have dipped in a more limited role in recent years. He scored 11 times in 44 appearances across all competitions for Juventus last term, but he found the net for his club at least 20 times in eight seasons during a 10-year stretch beginning with Real Madrid in 2008-09.
Moving to Miami, where he should take on a prominent role and face less strenuous competition, gives him a golden opportunity to become a high-impact contributor once again.
"Training, perfecting my craft, the desire to improve on anything I did wrong, never give up, never lose the motivation or the desire to continue to learn," he told the club's website about what helped him achieve past success. "As good of a player as you might be, or as much as you have played at the elite levels, there's always motivation to continue to improve."
The Herons, led by president David Beckham, have struggled during their debut season with a 2-7-2 record through 11 matches.
It hasn't been announced when Higuain will make his debut. Miami is scheduled for a road match against Atlanta United on Saturday. After that, there are two matches left in the regular season, next Wednesday at home against the New York Red Bulls and Sept. 27 on the road against the Philadelphia Union.