401-k plan, 401-k - a retirement savings plan that is funded by employee contributions and (often) matching contributions from the employer; contributions are made from your salary before taxes and the funds grow tax-free until they are withdrawn at which point they can be converted into and IRA; funds can be transfered if you change employers and you can (to some extent) manage the investments yourself --1is a kind ofpension plan, pension account, retirement plan, retirement savings plan, retirement savings account, retirement account, retirement program