The senators, 31 Republicans and 29 Democrats, sent Obama a letter, The Hill reported. The letter urges the president to adopt reforms suggested by the fiscal commission he named last year.
The letter was sent as the president signed a bill appropriating enough money to keep the government running through April 8.
"Specifically, we hope that the discussion will include discretionary spending cuts, entitlement changes and tax reform," the senators said.
Sen. Mike Johanns, R-Neb., who circulated the letter with Michael Bennett, D-Col., acknowledged it will be difficult to make changes to entitlement programs like Social Security and Medicare and to the tax code. He said the president's commitment is necessary before anything can be done.
"The ball is very clearly in the president's court," Johanns told The Hill.
The senators did not make specific suggestions for entitlement or tax reform. Republicans resisted Obama's effort to roll back Bush-era tax cuts on upper-income taxpayers.