Hard pressed families with private Vhi Healthcare are facing a massive €331 hike in fees to keep precious parents and children cover.
From next month insurance for a mother, father and their two children is to increase 15pc, or €27.60 a month, the company revealed.
The huge hikes will heap further pressure on cash-strapped families already counting the cost of tax hikes and child benefit cuts announced in the Budget.
Premiums for other plans could see increases as high as 45pc.
Jimmy Tolan, Vhi Healthcare chief executive, said the company was losing €170m a year because it holds a larger proportion of older customers more in need of care than other insurers.
"We anticipate that our customers will require 10pc more healthcare in 2011 compared to 2010," he said.
"Today's price increase is necessary to provide healthcare cover for all of our customers."
The Vhi lost about 48,000 customers in the last year.
Vhi said 60pc of its customers will see the cost of their premium increase by 15pc when their policy is due for renewal.
Other tailored and more specialist plans, such as Plan B and Plan B options popular among older customers, will rise by 35pc and 45pc.
The cash hit facing Vhi patients looks like this:
- An adult on Plan B faces hikes of €317 to €1,224
- Plan B Options by €444 to €1,430 from February 1
- Families on the Parents & Kids plan, the most popular family cover, will see premiums increase by 15pc or approximately €331 a year.
James Reilly, Fine Gael health spokesman, said the Vhi had failed after 50 years in business to control health costs in Ireland.
"Just as the full impact of Budget 2011 is hitting pay packets and the children's allowance has been slashed, families are now being asked to pay for the cost of recapitalising the Vhi after years of Government inaction," he said.
"The Vhi has hiked its premiums for the third year in a row, this time by 45pc on some policies, on top of a 48pc increase imposed over the last four years."
Jan O'Sullivan, Labour's health spokesman, said the price hikes will force more people to give up private healthcare cover.
"These increases will lead to a situation where many policy holders will reduce or drop their health cover, placing yet more pressure on the public health system," Ms O'Sullivan said.
"For years we have had to suffer the consequences of a dysfunctional healthcare system and now it seems we have an increasingly dysfunctional health insurance system."