The introduction of free GP care for seven and eight-year-olds should be done on a phased basis, according to doctors representatives.
Taoiseach Leo Varadkar has committed to the move next year.
The Department of Health said: "The Government intends to extend GP care without fees to all children aged between six and 12 years on a phased basis, starting in 2020. Legislative changes will be required to give effect to this extension.
"As part of the recent agreement reached on GP contractual reforms and service developments, the IMO has agreed that it will engage with the Department of Health and the HSE in relation to the contractual aspects of this service in advance of implementation."
Children up to the age of six are already covered by an existing scheme.
President of the Irish Medical Organisation Padraig McGarry, said it should be introduced in a way that minimises disruption.
Mr McGarry said: "What we have indicated, we want to have this done on a phased basis so that's it's not done in a big bang solution.
"In that way, it should minimise the effect on capacity, but it will have an impact, obviously, when there are more patients."