His comments come the same day the House passed a budget that helps pave the way for a Republican-sponsored plan that would slash corporate and personal taxes and generally reform the nation's tax code.
"I think there will be immediate impact and that people will have the optimism which is built around it fulfilled, which has been really a part of the problem for a lot of policy decisions," Moynihan told CNBC's "Fast Money Halftime Report." "That's a good thing. Is there a danger of retrenchment if it doesn't happen? Yes, absolutely. Do we need it as a country? Yes, we need to have a lower tax rate to be competitive."
At a time when the financial sector has been left behind by a strong stock market rally, BofA has stood above the crowd even as it has had to withstand some of the same headwinds as other banks.
The second-largest U.S. bank by assets reported third-quarter earnings of 48 cents a share, ahead of Wall Street estimates. BofA did say it had seen a 22 percent slide in bond trading, mirroring a broader industry trend.