There are many reasons you may want or need to roll over your 401(k) or IRA. And luckily, it’s not as hard as it sounds if you know what you’re doing. If you have old 401(k), 403(b), or 457 accounts from past employers, there could be a few reasons to keep things the way they are. Some people may prefer to roll over their old 401(k) into a new 401(k), but that puts you at the mercy of your new plan’s fees and investment options. That might not be the best place for your old money.