You may not have to take a retirement plan withdrawal, but it's important to understand the rules.One of the nice things about saving for your senior years in a traditional retirement plan is getting to score a tax break on the money you contribute. If you're a higher earner, that tax break could be especially lucrative.Plus, with a traditional IRA or 401(k), your money grows on a tax-deferred basis. You don't have to pay taxes on investment gains year after year as you do with a regular brokerage account. ...