New figures show family doctors are split on support for free GP care for the under-sixes, with the scheme due to go live in less than three weeks.
The Health Service Executive said 53% - or 1,274 of the 2,413 GPs who hold medical card contracts - have signed up, with 42 GPs signing up to the scheme today.
The HSE also wrote to a further 336 GPs who do not hold such contracts, inviting them to sign up.
The website to allow parents pick a doctor on the scheme is due to be operational from Monday.
The areas with the highest uptake of GPs are Donegal, 93%; Roscommon, 90%; and Longford/Westmeath at 81%.
The lowest uptake is in south Tipperary, where just 8% of GPs have signed up.
Other areas of low uptake include Cork South, 22%; Louth, 22%; and Kildare/West Wicklow, 25%.
In Dún Laoghaire, Co Dublin, just 32% of GPs have signed up.
The highest uptake in Dublin is in Dublin west, where 71% of GPs have signed up.
The National Association of GPs, which is opposed to the scheme, has said many GPs feel bullied and are signing up under duress.
The Irish Medical Organisation, which negotiated the deal, said it believes that in time the vast majority of GPs will sign up, but that it is an individual decision.
