The agency's last offer will become final if Congress doesn't intervene within 60 days.
PAY & BENEFITS - ALL ARTICLES
Merit Systems Protection Board says officials should make decisions about controlling costs and issuing ratings before designing systems.
Agency says it still wants to reach agreement, but union maintains formal negotiations have ended.
Cash incentives of as much as $25,000 were used in half of all government agencies in the last three years.
The F Fund, made up of fixed-income bonds, was the only option to lose ground.
Which retirement system is really better?
Air traffic controllers' union says meeting scheduled for next week is just a formality and that the two sides are at an impasse.
Agencies have the authority to grant retention bonuses to keep peak performers from leaving.
Bill would remove burden from individual agencies to find money for the benefit.
Buy-in will be the last within-grade increase seen by employees moving to the Pentagon's new personnel system in April.