The Health Service Executive (HSE) had run a deficit of €281m by the end of July this year.
HSE chief executive officer Paul Reid will tell an Oireachtas committee on Wednesday that the service is running well over budget.
In June the new HSE chief told TDs he thought the HSE could break even this year.
At that stage the deficit the organisation was running was tabbed at €103m by the end of March.
He will tell the Oireachtas Health Committee on Wednesday that that deficit became €281m by July.
It means health will likely require another large bailout, despite being given a record budget in 2019.
However the deficit at the same time in 2018 was 72% higher, at €485m.
Mr Reid will tell TDs and Senators he has instructed HSE managers to limit overspend as much as they can.
He will say that those measures will include curbing the spend on agency staff, overtime and staffing levels.
Reporting by Sean Defoe