The Premier League leaders will not formally sign the player until the summer though, allowing Zaha to help Crystal Palace attempt to win promotion.
A Manchester United statement read: “Manchester United, Crystal Palace and Wilfried Zaha have reached an agreement for the player to join Manchester United in July 2013.
“The player is having a medical in Manchester today [Friday, 25 January]. There will be no further comment by any party until Wilfried joins United in July 2013.”