The U.S. has a special tax credit designed to help lower-income Americans save for retirement. It's called the "Retirement Savings Contribution Credit" or "Saver's Credit." Those who earn less than $33,000 annually ($66,000 if married filing jointly) may qualify for a tax credit of 10%, 20%, or 50% of their retirement contributions. This tax credit applies both to pre-tax contributions, like those made to a 401(k) plan, as well as post-tax contributions, like those made to a Roth IRA.