Tim Howard will leave Everton for MLS side Colorado Rapids at the end of the season.
The United States goalkeeper is returning home after 13 years in England and 10 at Goodison Park.
Howard, 37, has lost his place to Joel Robles in recent weeks and agreed a three-and-a-half-year deal with the Rapids after discussing his future with Everton boss Roberto Martinez.
He will assume an informal ambassadorial role for Everton when he embarks on the next chapter in his career and said he will be "an Evertonian for life".
Howard said: "I've had a fantastic career in England and in particular at Everton, but as football clubs move forward and players have careers to think about you always have to make decisions.
"This one crept up on me - I had two more years at Everton which I planned on seeing out, but when I spoke to my family, Roberto Martinez and the chairman I thought the decision and the timing...just seemed to be the right move.
"The Rapids are trying to build something special - they've won an MLS Cup, know what it is to be a winner and they're trying to get back to those heights.
"The plan they've put in place excited me - it's a project and something I'm looking forward to. This isn't a quick thing - it's three-and-a-half years and I'm looking forward to being part of this club."
Martinez said it has been a pleasure to work with Howard and praised the influence he has had on young players at Goodison Park.
"Tim is such an incredible character," he said. "With certain players, their contribution goes a little bit further than starting in the team or not and Tim is probably the perfect case of that.
"He is such an influence on the young players. We had a really good group of young players coming through in the last three years and Tim has been a vital player in helping those players feel Everton and to understand what it takes to play in the team.
"We have got a lifelong ambassador for our football club in the USA. We have a large following and a big Everton community in the USA because they were introduced to us through Tim Howard.
"He has been the most significant ambassador we had in America. Now we will have an Evertonian playing in the MLS and he will carry the name of Everton wherever he goes."