"I strongly suspect it was massively stupid for our government to rely so heavily on printing money and so lightly on fiscal stimulus and infrastructure," Munger told CNBC's "Squawk Box."
Japan has struggled mightily to come off its economic funk and, earlier this year, in an unprecedented move the Bank of Japan implemented negative interest rates.
"It surprised all the economists of the world," Munger said.
The U.S. Federal Reserve raised interest rates by 0.25 percent in December, but levels remain near historical lows.
"I think we would've been way better off if we'd used fiscal stimulus because … this [low interest rate] approach runs out of fire power," Munger also said.