The Roth conversion window

what September means for your tax picture.

The fourth quarter is the most valuable window of the year for Roth conversion analysis. By September, most people have enough year-to-date income information to project where they will land for the year and enough time to execute a conversion before December 31 if it makes sense.

Here is what a Roth conversion is, why the timing matters, and what goes into a sound analysis.

What a Roth conversion is

A Roth conversion moves money from a traditional IRA or pre-tax 401(k) to a Roth IRA. The converted amount is taxable income in the year of conversion. In exchange, that money grows tax-free and is never subject to Required Minimum Distributions.

The question is never whether a Roth is good. It is whether converting now and paying the tax today produces a better outcome than deferring the tax until distributions are taken in retirement.

Why the fourth quarter is the right window

Roth conversion decisions require knowing your actual income for the year. Converting too early in January or February means guessing at your income. A large bonus, an unexpected capital gain, or a business distribution you didn't anticipate can push a conversion into a higher bracket than planned.

By September, most of those variables are known. You can model the conversion with your actual year-to-date income, project the remainder of the year, identify the exact bracket space available, and execute a conversion that fills that space precisely without crossing into the next bracket unnecessarily.

What makes a Roth conversion worth doing

Your current tax rate is lower than your expected future rate. If you are in a lower bracket now than you expect to be in retirement, because of a gap year, early retirement, a business transition, or simply because RMDs will push you higher later, then converting at the lower rate today makes mathematical sense.

You have bracket space available. If your taxable income for 2026 is well below the top of your current bracket, a partial conversion can fill that space at the current rate rather than allowing the money to be taxed at potentially higher rates later.

You can pay the tax from non-IRA funds. A Roth conversion paid from the converted funds themselves is less efficient than paying the tax from a taxable account, preserving more in the Roth to grow tax-free.

Your estate planning goals include leaving tax-free assets to heirs. Roth accounts pass to heirs without immediate income tax. For clients with large traditional IRAs and charitable or family estate planning goals, a conversion strategy can be a significant tool.

What complicates the analysis

Roth conversions interact with Medicare IRMAA surcharges, net investment income tax, Social Security taxation thresholds, and state income taxes. A conversion that looks efficient at the federal level may create unintended costs when all these factors are considered together. This is why integrated tax and financial planning where the same person who manages your financial plan also prepares your tax return produces better outcomes than advice given in isolation.

What is a Roth conversion and should I do one?

A Roth conversion moves pre-tax retirement funds to a Roth IRA, triggering income tax now in exchange for tax-free growth and distributions later. Whether you should do one depends on your current tax rate versus expected future rate, available bracket space, ability to pay the tax from non-IRA funds, and estate planning goals. The fourth quarter is the best time to analyze this because you have accurate year-to-date income data to work with.

When is the deadline for a Roth conversion?

December 31 of the tax year. A Roth conversion counts as income in the year it is completed. If you want the conversion to affect your 2026 tax return, it must be completed by December 31, 2026.

How much should I convert in a Roth conversion?

The exact amount requires projecting your total income for the year, accounting for all sources, and identifying the remaining space in your bracket. This analysis should be done with a tax professional who has access to your full financial picture.

This content is for educational purposes only and does not constitute personalized tax or financial advice. Roth conversion decisions depend on individual circumstances including income, tax bracket, state taxes, Medicare status, and estate planning goals. Consult a qualified tax professional or financial advisor before executing a Roth conversion. Past tax law is not a guarantee of future tax treatment. Integritas Wealth Strategies, LLC is a state-registered investment adviser in South Carolina.