The Chief Executive of the Health Insurance Authority Liam Sloyan says the effect of the health insurance levy on premiums is hugely overstated.
The levy was designed to help insurers with their differing costs and most of it goes to the VHI, which has a higher proportion of older customers.
But some private health insurance companies say the levy leads to higher premiums and are calling for it to be scrapped.
However, speaking before the Oireachtas Health Committee, Sloyan says insurers have to look at the levy as well as the tax credits they receive in order to tell the full story.
"The credits in some cases more than cancel out the impact of the levy. In other cases, where there is a younger population they less than cancel out the impact of the levy.
"You have to look at both together. When you do that, you will see the statements in relation to the impact of the levy on the prices of the premium for predominantly younger populations are hugely overstated."
Meanwhile, the head of the VHI has told the committee that strict rules are needed in the health insurance market to make sure there is no incentive for risk selection.
John O'Dwyer says risk equalisation is an essential part of any move towards universal health insurance.
"Clearly, we believe there must be very tight rules in the market place to ensure there is no incentive for risk selection," he said.
"For community rating to work, we must have good police and that means a very comprehensive risk equalisation scheme."