The federal government has added an expensive cystic fibrosis drug to the PBS to help extend the life expectancy of babies suffering from the disease.

The price of an expensive drug used to treat cystic fibrosis will be dramatically reduced for the parents of babies suffering the disease.

Federal Health Minister Greg Hunt will announce on Sunday that Kalydeco, which costs up to $380,000, will be listed on the Pharmaceutical Benefits Scheme for babies aged 12 to 24 months.

"Families will be able to access this medicine and will pay up to $40.30 per script, or $6.50 with a concession card," Mr Hunt told the Sunday Tasmanian.

Early intervention with the drug raises the life expectancy for cystic fibrosis sufferers.

At present about 280 Australians aged two upwards use Kalydeco.

"For these babies to now have access to it from the age of 12 months old is just remarkable," Cystic Fibrosis Australia chief executive Nettie Burke said, calling it life-changing.

"Their young lungs will be so much more healthy as they go through their life.

"They'll have a longer life and a better life."