How to Pay Taxes on a Roth Conversion

Planning a Roth conversion? In this article, we’ll break down exactly how to pay taxes on a Roth conversion, avoid common mistakes, and stay tax-efficient.

Understanding How Roth Conversion Income Is Taxed

Understanding how Roth conversion income is taxed is essential. The IRS applies different tax treatments to various types of income. For Roth conversions, the IRS taxes that income at your ordinary income tax rate—also known as your income tax base or marginal tax bracket.

The easiest way to understand this is by looking at the tax table. Any Roth conversion income is added on top of your existing income and taxed at the marginal rate that applies. So it’s important to know what tax bracket you’re in.

For example, if you’re married filing jointly and trying to stay within the 24% tax bracket—a bracket we’ve often referred to as a sweet spot for Roth conversions—then in 2023, you can have up to $364,200 of income (including your Roth conversion) before moving into the next bracket.

As always, it’s important to forecast where future tax rates might be. Conversions only make sense if you believe you’re in a lower tax bracket today than you’ll be in the future.

Calculating the Taxes on a Roth Conversion

Let’s say you’re targeting the 24% bracket and determine that converting $100,000 from your traditional IRA to your Roth IRA makes the most sense. At a 24% federal rate, that’s $24,000 in federal taxes.

Assume a 6% state income tax rate, and your total tax burden on the conversion rises to 30%, or $30,000. Your state rate may differ, but this gives us a clean example to work from.

Where Should the Money Come From?

One of the most important questions before doing a Roth conversion is: Where is the $30,000 going to come from?

Ideally, you use assets from your non-retirement accounts. We often talk about the three tax buckets:

1. Non-retirement accounts
2. Traditional retirement accounts
3. Roth retirement accounts

That first bucket is the best place to draw from. It also matters how the money is invested—or whether it’s invested at all. Ideally, that money is already sitting in cash, money market, or savings.

If your money is invested, you may need to sell assets. That can trigger capital gains. The IRS taxes long-term capital gains at preferential rates, and they are not included in your income tax base. But short-term capital gains are treated as ordinary income and do count toward your tax bracket.

Also watch for interest income from CDs or bonds, which is taxed at your income rate and could push you into a higher bracket.

What If You Don’t Have the Cash?

So what if you don’t have non-retirement account funds to pay the taxes? Should you still consider a Roth conversion?

In many cases, yes—because the biggest factor is your current tax bracket versus your future tax bracket.

Let’s say the $100,000 conversion puts you right at the top of your desired bracket. If you take another $30,000 from your IRA to pay taxes, you’d move into the next bracket.

Instead, you might convert $70,000 and take a $30,000 IRA distribution to cover taxes. That keeps your total taxable income within the bracket and pays your bill.

It’s not ideal, but when we run the numbers in financial planning software, this often still works well.

The 10% Penalty Rule

If you’re under age 59½, using IRA money to pay taxes on a Roth conversion may trigger a 10% early withdrawal penalty. That applies to the $30,000 distribution and makes this strategy much less attractive.

If you’re over 59½, you can avoid the penalty. You take the $30,000 from your IRA to pay taxes and convert the remaining $70,000. It’s not as efficient as using outside cash, but it still works.

When to Pay Taxes on a Roth Conversion

Many people make mistakes here. The IRS requires estimated tax payments in the same quarter you receive income.

Here’s how it breaks down:
Q1 Conversion → Pay by April 15
Q2 Conversion → Pay by June 15
Q3 Conversion → Pay by September 15
Q4 Conversion → Pay by January 15 (next year)

Use Form 1040-ES to make federal estimated payments. If your state collects income tax, you’ll need to make estimated payments there as well. Missing these deadlines can trigger underpayment penalties.

Other Financial Considerations

Your Roth conversion can also affect your broader financial situation.

If you’re under 65 and buying insurance on the ACA exchange, your conversion income counts toward subsidy eligibility. A large conversion could push you out of subsidy range.

If you’re 65 or older and on Medicare, higher income could trigger IRMAA—the Income-Related Monthly Adjustment Amount—which raises your Medicare premiums. Even if you’re still in your target tax bracket, your Medicare costs may rise.

These trade-offs don’t necessarily mean you should avoid a Roth conversion. But it’s important to understand the full picture—short-term costs vs. long-term tax savings.

Final Thoughts on How to Pay Taxes on a Roth Conversion

We’ve now taken a deep dive into how to pay taxes on a Roth conversion—from calculating the tax, to identifying where the money should come from, to understanding timing and broader consequences.

If you’re looking for additional help with this or want to dive deeper into your specific situation, be sure to check out our Wealth Vision Financial Plan, our Retirement Time Machine course, and other great resources on our website.