Money What is a 401(k) and how does it work? What happens when you quit or get fired? December 9, 2022April 11, 2023 Elisabeth Buchwald, USA TODAY Comments Off on What is a 401(k) and how does it work? What happens when you quit or get fired? What is a 401(k)? Is it the same thing as an IRA? Both are tax-advantaged retirement investment accounts but they have key differences.