Moore said the 28 players announced today weren't necessarily guaranteed a spot in the 2018 Black Ferns team and they would need to continue to work hard in their club teams and provinces to be considered for the black jersey.
"We have a Black Ferns training camp in mid-June when we'll get a much better idea of how everyone is tracking. There's also the possibility we'll offer a contract to players outside of the initial contracted squad."
Moore said there were two more contracted positions to be filled.
NZR recently announced the Black Ferns would play two Test matches against Australia for the Laurie O'Reilly Memorial Trophy. Both August Tests will be double-header fixtures with the All Blacks Bledisloe Cup matches versus Australia.
On November 3, the Black Ferns will face USA Eagles women in a triple header with the Maori All Blacks v USA Eagles and Ireland v Italy at Soldier Field in Chicago.
NZR Head of Women's Rugby Cate Sexton said the signing of contracts, under the newly introduced Black Ferns Performance Programme, marked a significant moment in rugby and reflected the growing interest in women's rugby in New Zealand as well as globally.
"We have a very talented pool of female players to select from and the pool is increasing every year. We want to make sure we nurture our talent and provide our best players with the training and support they need to achieve at the highest level.
"These contracted players will receive a guaranteed retainer to train, assembly fees when they come together for Black Ferns camps and the medical and technical services they need as elite athletes."
The 2018 Black Ferns contracted squad is:
Backs:
Chelsea Alley (Waikato)
Ariana Bayler (Waikato)
Grace Brooker (Canterbury)
Kendra Cocksedge (Canterbury)
Krysten Cottrell (Hawke's Bay)
Ruahei Demant (Auckland)
Kilistina Moata'ane (Otago)
Victoria Subritzky-Nafatali (Counties Manukau)
Kristina Sue (Manawatu)
Renee Wickliffe (Bay of Plenty)
Selica Winiata (Manawatu)
Forwards:
Eloise Blackwell (Auckland)
Les Elder (nee Ketu) (Bay of Plenty)
Fiao'o Faamausili (Auckland)
Dhys Faleafaga(Wellington)
Harono Iringa (Counties Manukau)
Aldora Itunu (Auckland)
Linda Itunu (Auckland)
Pip Love (Canterbury)
Charmaine McMenamin (Auckland)
Toka Natua (Waikato)
Joanah Ngan Woo (Wellington)
Te Kura Ngata-Aerengamate (Counties Manukau)
Aleisha Nelson (Auckland)
Marcelle Parkes (Wellington)
Leilani Perese (Counties Manukau)
Aroha Savage (Counties Manukau)
Charmaine Smith (Auckland)