ROTH 401K and ROTH IRA accounts provide retirement savings options which are fully tax free upon withdrawal as long as they comply with certain IRS rules. A disadvantage of ROTH IRA accounts is that they are restricted to lower income earners. In order to contribute to a ROTH IRA for the 2017 tax year, your adjusted gross income must be less than $196,000 if you are married filing jointly and less than $133,000 if you are filing as single or head of household, and the amount of the allowable contribution phases out as it approaches these limits.
A ROTH 401K plan, unlike a ROTH IRA, has no income limits for the participant. Regardless of income, for the 2016 tax year an individual may contribute up $18,000 to a 401K account (ROTH or traditional). This limit increases to $24,000 for participants age 50 or older. Unlike a traditional 401K plan, contributions made to a ROTH 401K are made on an after tax basis. Keep in mind that employer contributions to a 401K plan, unlike ROTH 401K employee contributions, are always taxable to the plan participant upon their withdrawal.
Whether or not a high income earner should contribute to a ROTH 401K plan depends on a variety of factors. On one side of the argument, a high income earner is in a high tax bracket and may be better off contributing to a traditional 401K as the immediate tax benefit could be significant. On the other hand, ROTH 401K accounts have numerous advantages related to tax free withdrawals as well as limited rules related to required minimum distributions. A careful analysis should be done of your financial situation, with particular attention paid to your tax bracket now and your expected tax bracket in retirement.