Ex-wicketkeeper Foster has been appointed as an assistant coach for the Black Caps, while former batter Bell will feature in the team's rotating staff in the lead-up to the tournament.
Foster, a Twenty20 coaching expert, will link up with the New Zealand team for a one-day series against England starting on September 8, rejoining the squad for the World Cup in India starting in October.
Multiple Ashes winner Bell will join as an assistant coach for the T20 series against England starting next week and remain on staff for the following ODI series against England and Bangladesh.
Former New Zealand captain Stephen Fleming, who has enjoyed huge success coaching in the Indian Premier League, will also link up with the squad for the ODI series against world champions England.
Saqlain Mushtaq, previously coach of Pakistan, will be New Zealand's spin bowling mentor for the Bangladesh Test series in December, having joined the squad for the white-ball tour of his home country in April.
New Zealand head coach Gary Stead will sit out the Bangladesh tour after the World Cup, with Luke Ronchi stepping in for the Test series starting on November 28.
Team manager Simon Insley said the coaching additions would balance workloads and bring fresh ideas to the group.
"Following the T20 team's departure to the UAE (on August 12), the team will be on the road right through until December 16 when the Test team returns, ahead of a busy home summer," he said in a statement.
"That period of time playing, working and simply being away from home is not sustainable and we've worked really hard this winter to ensure everyone from players to staff will receive adequate rest.
"We're delighted with the calibre of coaches we've been able to confirm to assist the Black Caps on the various tours."
10°C