"We thought we could stick out a year apart with visits, but have come to the conclusion our family life is too important," said Mr Mason, who has decided to join his wife in the US until the fellowship ends in August.
He described his period with NZX-listed Ryman Group as an invaluable corporate learning experience and said he was sorry to be leaving.
Ryman regional manager Wendy Taylor, who oversees six villages in the North Island, said Mr Mason had done a wonderful job, greatly adding to the vibrant village community.
She noted that in the past year the Bethlehem-based village had achieved 100 per cent occupancy in the 120 room Care Centre (Rest Home, Hospital and Dementia Unit) for the first time.
Mr Burnett's resignation last week from heading the chamber came as a surprise to many in the business community.
Both Mr Burnett and chamber board chairman Luke Stewart told the Bay of Plenty Times the split was amicable.
"There's nothing untoward," said Mr Burnett who will finish on March 31.
Board vice-chair Toni Palmer will be acting chief executive while they search for his replacement.
"It's just time to move on and look for new challenges."