New pension arrangements have come into effect for all new public servants.
The provisions will not affect existing public servants but will impact any new teachers, nurses, gardaí, judges and politicians who join after January 1.
The new rules bring to an end the system whereby pensions are calculated on final salary at retirement.
A pension will now be based on average earnings across a person's career.
Minister for Public Expenditure and Reform Brendan Howlin says the reform is ground-breaking.
"We've spent a year bringing in these changes in the Dáil and Seanad,
"These were part of the arrangements negotiated with the Troika. They have been, I can't say supported because they haven't been supported, but they haven't been resisted by the public sector unions.
"They are a fundamental change in the way pensions will be calculated into the future."