the IRA, but funded with after-tax dollars, with distributions being tax-free Roth 401(k) - Introduced in 2006; a 401(k) plan with the tax features of a Roth IRA References External links IRS Retirement Plans Community site West's Law Encyclopedia entry on pension at www.enotes.com Different Types of Retirement Plans Comparison NerdWallet June 29 2016 Official U.S. Government Website Publications from the U.S. Department of Labor, which include those on retirement plans