The drug buying agency Pharmac says claims its policies are causing preventable deaths are completely baseless.
US pharmaceutical companies are pushing for changes to the way the agency works at a crucial stage of free trade talks that include the United States and New Zealand.
The Pharmaceutical Research and Manufacturers of America says New Zealand does not buy as many drugs as other developed countries, meaning there are more deaths from treatable diseases.
The lobbying comes as the US prepares to outline its position on protections for the pharmaceutical industry in the TransPacific Partnership trade talks.
But Pharmac says the drug company claims are without foundation.
Spokesperson Jude Urlich says Pharmac's role is to improve the health of New Zealanders and that's exactly what it does.
She told Checkpoint a 2005 New Zealand Medical Journal article showed evidence that by not funding Cox-2 inhibitors - used for arthritic pain - Pharmac has saved 487 statistical lives a year through its decision to fund 18 other drugs from the funding available at that time.
"Moreoever, if Pharmac had funded Cox 2 inhibitors at the same rate as Australia we would have had between 330 and 1900 people die of heartattacks over those four years." she said.
Ms Urlich said that is the only published data but says there are other cases where Pharmac has decided not to fund drugs to see them later withdrawn by other countries.
She says comparing last year's expediture with prices Pharmac was paying in 1999 shows the agency saved $937 million in that year alone.