The 28-year-old defensive midfielder is due to fly out imminently to finalise personal terms on a move that appears all but sealed.
Reo-Coker, whose wife is American, has expressed excitement over signing for the Caps and can't wait to make his mark when the season kicks off on March 3:
"I am delighted, it will be a new experience and I can't wait. I am looking forward to the challenge."
It is something new for Nigel, and he is relishing the prospect of going.
He just wants to play football, and that chance has arisen in Major League Soccer and he now taking that with both hands.
Everything is sorted, and he just has to finalise the details when he arrives there.
Reo-Coker started his career at Wimbledon, and after a move to Portsmouth failed to materialise, he ended up at West Ham United. He rose through the ranks and became captain, leading his team to the 2006 FA Cup final where they lost to Liverpool.
He swapped claret and blue shirts shortly after, signing for Europe-chasing Aston Villa for £8.5 million under Martin O'Neill and Randy Lerner.
He was a key player alongside Gareth Barry in the engine room for several years, then sampled the likes of right midfield and right-back before eventually being frozen out of the squad.
Gerard Houllier released him on a free transfer and, after a season with Bolton Wanderers and a short stint with Championship side Ipswich Town, is on the verge of making the well-marked transition to Major League Soccer.
Caps fans will be getting a midfield destroyer in its purest form. Reo-Coker does not have the ability to launch an accurate 50-yard pass to release a flying winger, but what he does have is the mental and physical strength to inspire his teammates.
He's committed and robust in the challenge, dogged in his marking and vocal on the pitch. His versatility has stood him in good stead, but he operates best as an anchor midfielder just in front of the back four.
The Caps are getting a good player who, unlike many others joining MLS sides from Europe, is not over the hill in terms of career. All he needs a place to feel like home.