For many workers, a 403(b) retirement plan is a better option than a 401(k) because it offers the possibility of making larger catch-up contributions. If you've been working for 15 years or more, you can add extra funds to your 403(b) account beyond your regular contributions and any employer contributions. This is not an option with a 401(k) plan. Despite this difference, 401(k) and 403(b) plans are largely similar in terms of how they work and what they offer.