Fees paid to GPs and pharmacists for State services are to be cut by around 7.5% to save €70m a year.
The cuts are being introduced by Minister for Health James Reilly.
GP fees will be cut by 7.5%, saving €38m.
For pharmacists, the reduction is 7.6% and will save €32m a year.
The cuts are being introduced under the Financial Emergency Measures in the Public Interest Act.
Family doctors will get less money for administering the influenza vaccine and payments for patients over 70 years will also be cut.
For pharmacists, the retail mark up for drugs dispensed under the Drug Payments Scheme and the Long Term Illness Scheme will end.
The cuts are aimed at bringing GPs' and pharmacists' payments into line with the changes under the Haddington Road Agreement, which does not cover these health professionals.
The Irish Medical Organisation has warned that patient services at GP practices across the country will be significantly affected this winter, as a direct result of cuts.
Dr Ray Walley, chairman of the union's GP Committee, said this is the fourth in a series of cuts imposed on GPs in recent years which have taken €150m out of primary care.
He said the cuts would lead to long waiting lists to see a GP and would end any hope of free GP care for all.