Thousands of families with health insurance from Laya are facing price rises.
The insurer, which has 500,000 customers, is pushing up the cost of premiums on 77 plans by between €150 and €300 a year from the start of March. But it is also cutting the prices of some plans, and offering free cover for second and subsequent children on seven schemes.
The insurer is the first this year to announce a premium hike, with experts expecting others will follow.
Around a million consumers are due to renew their health insurance in the three months up to the end of March.
Laya's premiums will rise in cost by an average of 3.3pc, but some plans will be 12.7pc more expensive from March 1.
Laya managing director Donal Clancy blamed a rise in the number and cost of claims for medical procedures.
Broker Dermot Goode, of Totalhealthcover.ie, said families with two adults and two children would face rises of up to €325 in the cost of cover when they renewed from March.
He said a large number of the 77 plans going up in price would see increases of 6pc.
The insurer has introduced a new low-cost plan for those who bought cheaper plans last year to beat penalties - known as lifetime community rating - now being imposed on those who wait until they are over 34 to buy cover for the first time.
The new Laya Assure Protect plan is €495 per adult, but covers only public hospitals.
Laya is cutting prices by between 7pc and 8.5pc on all its Assure suite of plans, but again, these only cover treatments in public hospitals. The move comes just a month after Laya froze prices on a number of plans and cut the cost of others.
A number of price rises have been announced recently by Aviva and GloHealth. VHI put up prices by 2pc from last November. This means consumers who are renewing may find their plan has risen in price by up to 14pc since last year.
Mr Goode said a failure to seek out better value could see families having to fork out an additional €1,000 to €2,000 if they were not careful. And they may not even end up with better cover for all that extra expenditure.
Mr Clancy said: "The price review has been driven largely by the steady and double-digit increase in volume and cost of claims. In 2015, we saw a 17pc increase in the volume of claims and an almost 20pc increase in the cost of paying these claims, which corresponds with growth in our membership to more than half a million members last year."