I’m a Financial Expert: This Is the No. 1 Mistake Americans Make With Their 401(k)

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A 401(k) is one of the best and most powerful ways to save for retirement — but it’s easy to get it wrong. There’s an incredibly common misstep that can cost you tens — or even hundreds — of thousands of dollars by the time you retire. It’s not how much you make, how you invest or even which plan you choose.

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