The HSE is aiming to impose cutbacks totally almost €1bn next year, according to a revised service plan from the agency.
The plan was initially drawn up in October and had envisaged cuts of around €500m.
However, it had to be revised due to the massive deterioration in the public finances and the HSE is now seeking to slash an extra €400m from its spending.
The HSE is planning to make the savings through a range of measures next year, including a 50% cut in overtime, reduced in-patient admissions, shorter hospital stays and a review of A&E services.
The service plan also envisages more spending on medical cards, more beds and additional primary care teams.