Roth IRA Rules of Thumb

By Kaye A. Thomas
Current as of December 24, 2014

When in doubt go with the Roth: it’s usually the right decision.

There are plenty of details on choosing between a traditional account and a Roth account elsewhere in this guide. This page is for those of you who don’t want to plow through lots of analysis — or who want a quick way to check whether you came to the right conclusion. These rules of thumb represent my judgment about when it generally makes sense to choose the Roth account for your retirement savings. The reasoning behind these rules of thumb appears in other pages of this online guide and in our book, Go Roth!

Roth account vs. taxable account

One of the alternatives to a Roth retirement account is a regular taxable account with a bank, mutual fund or stockbroker. Either way you get no deduction when money goes in. The Roth account provides earnings that are tax-deferred and possibly tax-free. But if you make a taxable withdrawal of earnings from the Roth, you’ll report ordinary income (not long-term capital gain), and you may pay a 10% early distribution penalty.

  • Choose the Roth over a taxable account if you expect to qualify for tax-free distributions of the earnings. Remember, you can withdraw contributions tax-free at any time, but earnings generally have to stay in until you’re 59½ and have satisfied the five-year requirement.
  • If you expect to withdraw earnings when they’re taxable, you’re generally better off with a taxable account — especially if you’re investing for long-term capital gains, or if the 10% early distribution penalty will apply.

Roth account vs. nondeductible IRA

If you participate in a retirement plan maintained by your employer and your income is above certain levels, you may face a choice between saving in a Roth IRA or making a nondeductible contribution to a traditional IRA. In either case you get no deduction for your contribution, but the Roth IRA provides greater flexibility in withdrawing your contributions, and the possibility of withdrawing your earnings tax-free. This is an easy decision: the Roth IRA is better.

  • Choose a Roth account over a nondeductible contribution to a traditional IRA in all cases.

Roth account vs. deductible contribution

The choice between saving in a Roth account and making a deductible contribution to a traditional retirement account is more difficult. The traditional account gives you a deduction when you contribute, but the Roth gives you a chance to have earnings that are entirely tax-free for decades to come. Here are the main ideas here:

  • If you’re saving the maximum amount each year, the Roth account is likely to be better.
  • If you’re in a low tax bracket when saving, the Roth account is likely to be better.
  • Conversely, if you’re in a high tax bracket when you contribute and expect to be in a much lower tax bracket when you withdraw your earnings, a deductible contribution to a traditional retirement account may be the better choice, although the Roth can still win if you keep the money in the account for a long time period.

Roth IRA vs. employer plan

If your employer provides a 401k or similar plan, you may face a choice between contributing to that plan or a Roth IRA. Don’t forget you can do both!

  • Choose your employer’s 401k or similar plan if your employer will make matching contributions, and you don’t expect to forfeit the matching contributions by changing jobs before they’re vested.
  • If there’s no match or you’ve maxed it out, choose as you would for a deductible contribution in general (see above).

Many employers now offer Roth accounts in 401k and similar plans, so that you can obtain the benefits of Roth investing without giving up matching contributions or other desirable features of an employer plan.

Rules of thumb for conversions

Finally we come to the most complicated choice: whether to convert your traditional IRA to a Roth IRA.

  • Generally you shouldn’t convert to a Roth IRA if you need to hold out some of the IRA money to pay taxes on the conversion and you’ll pay the 10% early distribution penalty on the amount you hold out.
  • If your retirement tax bracket will be 15%, avoid paying 25% or higher on your conversion. Remember that a partial conversion may permit you to avoid pushing into a higher tax bracket in the year of the rollover.
  • If your traditional IRA contains mostly nondeductible contributions, converting it to a Roth IRA can produce handsome benefits over the long run.
  • Even if all contributions to your traditional IRA were deductible, converting it to a Roth IRA may produce benefits if the first two points above don’t apply.

Once again, these are merely rules of thumb. In most cases they give the right results, but your particular situation may call for a different answer.