In that case, it generally will make sense to do the conversion. For example, if your tax cost is $300,000 now and it would be the same or even higher in the future, converting has definite benefits. You would still have $1 million growing tax-free within your new Roth IRA.

Does it make sense to do a Roth conversion?

A Roth IRA conversion has a cost, which is the income taxes on the amount you convert. ... Consequently, it usually makes sense to pay for a conversion with the assets that will earn a lower after-tax return (taxable assets already outside of the Roth IRA).

When must Roth conversions be completed?

A conversion must be completed by December 31 to be included in that year's taxable income. Managing the tax impact of a Roth IRA conversion requires careful analysis. A review with a financial or tax advisor is always a good idea.