Whānau Āwhina Plunket is the largest provider of Well Child Tamariki Ora health services nationally, covering about 85 percent of the population.
But a review of the programme for under-fives has found it has been falling short for Māori, Pacific, disabled and high needs children and whānau.
Plunket's chief executive Amanda Malu said some families have been failed by both the programme and her organisation, and it needed to do better.
"We absolutely acknowledge that the health system and the Well Child Tamariki Ora programme has failed Māori and Pacific families and we absolutely acknowledge our part in that," she said.
"We have been very clear that as an organisation, Whānau Āwhina Plunket needs to do better and we have been working on ourselves for quite some time now in that area, and have done quite a bit of work really to think about how we can better deliver to Māori, Pacific, high needs whānau and those that are traditionally underserved by the system.
"We don't resile from those findings at all."
Malu said Plunket is already making changes, but it was waiting to hear more details from the government about the next steps for the Well Child programme.
But she said the organisation would not be trying to hold on to its current funding levels or contracts.
"We are not particularly concerned with protecting our contract or our funding," Malu said.
"We honestly believe that every baby in New Zealand needs the very best start in life that doesn't have to be a Whānau Āwhina Plunket start in life.
"We think we have a lot to bring to the system and to offer the Well Child Tamariki Ora programme in the future, but I'm certainly not trying to hold onto our funding at the expense of the right outcomes."
Malu said there was much more scope for health providers to work together and share resources.
Associate Health Minister Ayesha Verrall said options and costings for the programme's transformation would be developed over the next year.