The National Treasury Management Agency said it plans to borrow between €10 billion and €14 billion in 2020, down from a target range of €14-18 billion last year.
The NTMA said a pre-funding strategy had given it a projected cash balance in excess of €15 billion.
It said this gives it "significant flexibility" entering 2020 when it faces debt redemptions totalling almost €20 billion.
The NTMA said it will issue a statement at the beginning of each calendar quarter outlining the bond auction plans for that quarter.
It also intends to hold at least one syndicated bond deal during the year.
In a statement, it also said it will continue to issue Treasury Bills during 2020 and further details will be contained in the quarterly announcements.
Frank O'Connor, the NTMA's Director of Funding and Debt Management, said the agency's opening cash balance is projected to be in excess of €15 billion.
He said this means that despite facing redemptions totalling almost €20 billion, its funding requirement is lower than in previous years.
"2020 marks the last year in which redemptions of significant scale - the debt chimneys that we have faced - fall due. Post 2020, our annual debt redemptions will be lower," he said.
"This follows our programme of extending the average maturity of Irish government bonds, which has increased to close to ten years and is now one of the longest average maturities in Europe," he added.