The government has announced what it says is the largest Pharmac budget in its history.

Associate Health Minister David Seymour says it will spend nearly $6.3 billion on the drug buying agency over the next four years.

He says the new budget fixed a $1.7 billion fiscal cliff left by the former Labour government.

"In Labour's fiscal plan, they allocated $180 million annually. However, the true cost to secure Pharmac's budget is more than $400 million per year.

"This lack of funding jeopardised New Zealanders by potentially causing Pharmac to delist medicines, thereby reducing access to vital healthcare."

A deal to reform the Pharmac funding model is part of ACT's coalition agreement with National, while New Zealand First and National agreed to increase funding for Pharmac every year.

During the election campaign, Labour leader Chris Hipkins says Pharmac's funding has increased to $1.2b a year during his government's term in office.

This month The Detail reported there are more than 130 treatments on Pharmac's Options for Investment list - a wish-list of drugs and medical devices that it would like to fund but could not stretch to.

Read more: Pharmac's perpetually stretched budget

Last August, oncologists wrote an open letter to Pharmac appealing for newer and better funded medcation, saying the country is barely keeping pace with the World Health Organisation essential medicine list.

Seymour says funding for pharmaceuticals is "life or death, or the difference between a life of pain and suffering or living freely" for some New Zealanders.

"It's a priority for this government to find the additional $1.774 billion to prevent this from happening."

He says the government has committed the funding to make sure New Zealanders are able to access medicines they need to live a fulfilling life.

Seymour also points to other moves including the return of pseudoephedrine cold and flu medicines "within weeks" and streamlining Pharmac's approval processes so it could be assessing a funding application at the same time as Medsafe was deciding on regulatory approval for a drug.

On Sunday, he announced former deputy prime minister Paula Bennett had been appointed as Pharmac's board chair from next month.

Former Pharmac board chair Steve Maharey, who was previously a Labour minister, resigned from the role - and as the board chair of the Accident Compensation Corporation - in December.

-RNZ.