Captain Tom Christie and Blues winger Caleb Clarke have been retained from the victorious 2017 team, while at the other end of the scale there are eight players who will be eligible for selection again next year, including Trask.
Experience also comes in the form of 12 players who have played at Mitre 10 Cup level, while 27 of the 28 players have been involved in an Oceania Championship campaign.
"We found that a key factor to our success in 2017 was continuity, so it was important to see the bulk of this squad be involved in the Oceania campaign."
Philpott said there were strengths right across the squad.
"Laghlan McWhannell was the standout lock at Oceania and he is complemented by the two-metre duo of Will Tucker and John Akau'ola Laula. Our captain, Tom Christie, leads an exciting loose-forward trio that have been absolutely tireless in their efforts on the field.
"Vilimoni Koroi adds a point of difference in the back three alongside the genuine size and speed in the likes of Caleb Clarke and Leicester Faingaanuku, we are looking forward to seeing what they can create on the field."
New Zealand are set to face Japan, Wales and Australia in a tough pool-play assignment.
New Zealand Under 20 squad named for World Rugby Championship in France:
Forwards:
John Akau'ola-Laula, Auckland
Sione Asi, Manawatu
Tom Christie (Captain), Canterbury
Rob Cobb, Auckland
Devan Flanders, Hawke's Bay
Tom Florence, Taranaki
Ricky Jackson, Otago
Tevita Mafileo, Bay of Plenty
Laghlan McWhannell, Waikato
Xavier Numia, Wellington
Waimana Riedlinger-Kapa, Auckland
Hoskins Sotutu, Auckland
Flynn Thomas, Southland
Will Tremain, Hawke's Bay
Will Tucker, Canterbury
Kaliopasi Uluilakepa, Wellington
Backs:
Caleb Clarke, Auckland
Leicester Faingaanuku, Tasman
Scott Gregory, Northland
Vilimoni Koroi, Otago
Harry Plummer, Auckland
Billy Proctor, Wellington
Jay Renton, Southland
Xavier Roe, Waikato
Jamie Spowart, Tasman
Bailyn Sullivan, Waikato
Tanielu Tele'a, Auckland
Kaleb Trask, Bay of Plenty
Players not considered due to injury:
Tim Farrell, Hawke's Bay
Brayden Iose, Manawatu
Will Jordan, Tasman
Bradley Slater, Taranaki
Cameron Suafoa, Auckland
New Zealand Under 20 schedule (matches will be broadcast live on TVNZ Duke & streamed live on tvnz.co.nz)
New Zealand v Japan
Thursday May 31
7am (NZT)
New Zealand v Wales
Monday June 4
2.30am (NZT)
New Zealand v Australia
Friday June 8
7am (NZT)