Marcotte, 35, is a powerful all-rounder who won the US road race championship in 2014 and followed it up with the criterium title earlier this year.
Jamis manager Sebastian Alexandre said he began talking with Marcotte this year at the USA Pro Challenge.
"I was honestly looking at [Travis] McCabe or Marcotte, one of the two I think would be a good addition to the team," Alexandre said. "I talked to Eric and he was interested. He said he liked the team was interested in us.
"He said he was looking for a good team and a good organisation where he can race a couple more years, and he thought the team was a good fit. He knows we're looking to do the big races, and he wants to be a part of that."
Marcotte will join returning Jamis riders Lucas Haedo, Luis Amaran, Stephen Leece and Carson Miller on the 2016 team. Stephen Bassett, who this year won a stage of the Tour of Namur in Belgium with the U23 national team, comes to Jamis next year from the Hagens Berman development team.
Alaxandre said he will announce the remaining 2016 roster later this month.
Marcotte will boost the team's chances in the fast finishes, playing a role in the lead-out train for Haedo and also benefiting from that same lead-out train when the racing suits him.
"I was missing a lead-out rider for Haedo or another sprinter that Haedo could work for," Alexandre said. "Sebastian Hadeo can be the sprinter, but he can also be a great lead-out rider depending on the race. He is very experienced."
Marcotte's aggressive style of racing, his work ethic and his love of the sport convinced Alexandre that he would be a good fit for Jamis. He pointed to Marcotte's habit of getting up at 4 a.m. to train before the heat of the day in Arizona where he lives as a prime example of the rider's dedication.
"He's a guy who came late to the sport from what I know, and he just wants to race his bike," Alexandre said. "I really like that, and he seems very professional, which is another thing that I like from riders, when they take it seriously.
"For all those reason I thought he was a good fit. This is a tough year, so there were several guys looking for jobs. I just try to find guys who fit well in the team, besides just how strong they could be."
Marcotte's palmares also drew Alexandre to the rider.
"He's definitely a very, very strong guy," Alexandre said. "He can win in a small group. He can win in a reduced field. When the races get hard he can win. He can win from a break. He can win from the field. So it's a great addition."
Jamis lost secondary sponsor Hagens Berman this year when the Seattle law firm decided to throw its support behind Axel Merckx's Axeon development team, but with Jamis and long-time sponsor Sutter Home sticking with the program, Alexandre said the team will focus on quality rather than quantity.
"They like the team," he said of the sponsors. "They believe in what we do, and we'll continue."
The team will once again start next season at the Tour de San Luis in Alexandre's home country Argentina. Then Jamis will focus on earning invitations to the big North American races, including the Tour of California, Winston-Salem Classic, Philly Cycling Classic, the Tour of Utah and the USA Pro Challenge.
Riders not renewing with Jamis for 2016 include Gregory Brenes, Ian Crane, Ben Jacques-Maynes (retires), Daniel Aramillo, David Williams and Nate Wilson.