Liz Weston

Dear Liz: I’m leaving my job later this month and am trying to decide what to do with my 401(k) account. Some of my friends say to leave it where it is, and others say to roll it into a traditional individual retirement account or Roth IRA. Which is best?

Answer: You can’t roll a 401(k) directly into a Roth IRA. You would first need to roll it into a traditional IRA, then convert that to a Roth and pay the (often considerable) tax bill.

But let’s back up a bit. There are few reasons you might want to leave the money where it is, if you’re happy with your employer’s plan. Many large-company plans offer access to low-cost institutional funds that are cheaper than what you might find as a retail customer with an IRA.

Money in a 401(k) also has unlimited protection from creditors in case you’re ever sued or wind up filing for bankruptcy. When the money is in an IRA, the protection is typically limited to $1 million.

If you’re not happy with your old employer’s plan, you could transfer the account to your new employer’s plan if that’s allowed. If not, you can roll the 401(k) into an IRA, but choose your IRA provider carefully.

You’ll want access to a good array of low-cost mutual funds or exchange traded funds (ETFs). The costs you pay to invest make a huge difference in how much you eventually accumulate, so it’s important to keep those expenses down.

If you want help managing the money, many discount brokerages offer access to financial planners and some, including Vanguard and Charles Schwab, offer low-cost digital investment advice services. The services, also known as “robo-advisors,” use computer algorithms to invest and monitor your portfolio.

You’ll want to arrange a direct rollover, in which the money is transferred from your 401(k) account into the new IRA.

Avoid an indirect rollover, in which the 401(k) company sends a check to you. You would have 60 days to get the money into an IRA, but you’d have to come up with the cash to cover the 20% that’s withheld in such transfers. You would get that cash back when you file your taxes, but it’s an unnecessary hassle you can avoid with a direct rollover.

Before you decide to convert an IRA to a Roth, consult a tax professional.

Conversions can make sense if you expect to be in the same or higher tax bracket in retirement, which is often the case with young investors, and you can tap some account other than the IRA to pay the income taxes. But these can be complex calculations, so you should run your plan past an expert.