NZME managing editor Shayne Currie confirmed that Gifford would also join the New Zealand Herald as a weekly rugby columnist.
"Next year will be massive with the Rugby World Cup in Japan. Phil is a legendary rugby writer and columnist, who will provide insightful opinion, backed by decades of intimate knowledge and experience of the national game."
Gifford said joining Barnett on Newstalk ZB was a return to the best times he ever enjoyed in radio. "Simon was like family to me, basically the annoying kid bother I never had. Time hasn't changed that bond at all, and working together again is an amazing opportunity.
"I've had a long association with Newstalk ZB, and working fulltime with their off air team, who I know from personal experience are talented, hard working, and supportive, is something I look forward to enormously.
"On a very personal level Simon, Jodi and their family, and Jan and I and our family, have always been close, and the chance to share more time with them is a wonderful bonus.
"It's great to be extending my rugby relationship with NZME from radio to also include a rugby column in the Herald, in what will be an extraordinary year for the game.
"I believe Steve Hansen has revolutionised the way the All Blacks play the game, and the chance of another amazing World Cup in Japan next year, and the possibility of an All Black three-peat is hugely exciting."
Newstalk ZB Afternoons with Simon Barnett and Phil Gifford launches from mid 2019.