Families being hit with massive rises in Laya and Aviva health insurance plans have been warned not to accept the hikes. Instead, they should switch to other polices offered by the same insurers.
Some 65 Laya plans went up for those renewing from this month, in a move that will see families paying up to €500 more when they renew.
Aviva increased its rates by 5.5pc on average for those renewing or taking out a new plan from the start of last month.
The increases were imposed despite thousands of new customers taking up health insurance for the first time in May to beat new late-entry levies.
Laya's and Aviva's price rises will mean that a family of two adults and two children will be faced with increases of between €50 and €350 if they stay on the same plans.
Some plans will be €500 more expensive for a similar-sized family. Half of Laya's plans went up in price by an average of 4pc last week.
This comes after Laya imposed price rises of up to 26pc on a select number of corporate plans in July, after earlier withdrawing an entry-level plan.
However, Dermot Goode, of TotalHealthCover.ie, said the rises could be avoided.
Mr Goode warned families not to rely on their insurer to steer them to a better-value plan when they are renewing.
From now up to October tends to be when most health insurance plans fall due for renewal.
He said: "Don't just accept price hikes from the health insurers. There is so much choice in the health insurance market now that most consumers will be able to source equivalent cover and avoid the price hikes completely."
He said a family on Laya's Health Smart Family should opt for Connect Care 100 to avoid a hike in premiums of €519. Families that are insured on the Laya Essential Plus can avoid a €240 rise in its cost by choosing Total Health (No Excess).
The low-priced Essential Scheme from Laya is also going up, but the Assure Vitality plan is far cheaper for those who only want public hospital cover, Mr Goode said.
He added that Laya is offering free cover for families with two or more children under the age of 18.
Aviva customers on the Business Plan Select Plus should switch to Health Plan 16.1. Those on Aviva Level 2 Hospital will save by signing up for Health Plan 16.1.
GloHealth customers on Better Plan Ultra Cash will save by switching to the Best Smart plan. The insurer offers free cover for children under three years of age, Mr Goode said.
It recently emerged that as many as three out of four people with health insurance membership are still on the wrong plans and pay too much.
Mr Goode said even those who take the trouble to review their cover didn't realise that you need to do this annually, as with car or home insurance.