Geithner said Tuesday that it was "magical thinking" to believe that Congress could drum up enough revenue merely by looking to eliminate tax deductions, preferences and credits, and rate hikes must be part of the equation.
"I don't see how you do this without higher rates. I just don't see how you feasibly, realistically do it," he said.
However, he said he was heartened to see Republicans embrace the "basic reality" that revenues have to be part of the equation.
He also suggested that the drama over raising the debt limit in the summer of 2011 would not be repeated in the early months of 2013, when the Treasury next expects it will need an increase to that ceiling.
"That has never been judged as a responsible way to govern," he said. "My view is that the people who were part of that, and they're still there, will draw the right lesson from that experience."
He also shed a bit more light on when exactly he plans to leave the Obama administration, saying he expects to end his stint as Treasury Secretary "around the inauguration."