How to Convert 403(b) to Roth IRA | Conversion Calculator

A 403(b)-to-Roth IRA conversion is the transfer of assets from a tax-deferred employer-sponsored retirement plan into a Roth IRA, where qualified withdrawals in retirement may be tax-free.

The conversion is treated as a taxable event, with the transferred amount added to ordinary income in the year it is completed.

The decision to convert generally hinges on current income levels, expected future tax rates, and retirement timing, as it involves trading an immediate tax liability for potential long-term tax advantages.

403(b) to Roth IRA Conversion Calculator

Who Is Eligible to Convert?

A 403(b)-to-Roth IRA conversion is generally allowed, but your eligibility depends on a few specific IRS and plan rules.

• Anyone with a traditional 403(b) balance can convert
• Must have a “distributable event” first
• Plans that allow in-service withdrawals
• No restriction on income level or tax bracket.
• Only eligible rollover amounts can be converted

For those of you who are subject to RMD, you must take the RMD first. Only amounts above the RMD can be converted.

Also, if your 403(b) includes Pre-tax + after-tax contributions, then only the pre-tax portion is taxable on conversion.

How a 403(b)-to-Roth IRA Conversion Works?

Step 1. Confirm Eligibility and Account Setup

Check your 403(b) plan rules for in-service or post-employment distributions.

You must first confirm how much you plan to convert and make sure a Roth IRA is open and ready to receive funds.

Step 2. Estimate Tax Impact

The converted amount is taxed as ordinary income based on your tax bracket.

Estimate the tax liability in advance and plan to pay it from non-retirement funds.

If I were you, I would spread conversions across multiple years to manage tax brackets and avoid additional surcharges.

Step 3. Account for Required Minimum Distributions (RMDs)

If you are age 73 or older, withdraw any required minimum distribution first. RMDs cannot be converted. Only remaining eligible amounts may be rolled into a Roth IRA.

Step 4. Initiate Direct Roll Over

Next, request a direct trustee-to-trustee rollover from your 403(b) provider to your Roth IRA.

Funds are transferred directly between institutions and are not subject to withholding if processed correctly.

Step 5. Wait for Form 1099-R

By January 31 of the following year, the 403(b) plan will send you a 1099-R showing the distribution.

Box 7 will likely have code G, which is a direct rollover. If you did an indirect distribution, you would have received only 80% of the chosen amount (20% was withheld).

You then have 60 days from receipt to deposit 100% into the Roth using other funds to make up the withheld portion.

Step 6. Complete Indirect Rollover (If Applicable)

If funds are sent to you, redeposit the full amount into the Roth IRA within 60 days, including replacing any withheld taxes from personal funds.

By any chance, if you fail to meet the deadline, it will result in a taxable distribution.

Step 7. Report on Tax Return

On your tax return for that year, report the full amount of the distribution as IRA distributions line 4a/4b of Form 1040.

The taxable amount goes on line 4b.

Attach Form 8606 to document any basis and the conversion. If there was any after-tax portion, 8606 will calculate the non-taxable part.

Step 8. Pay Taxes Due

Make sure you have enough tax withheld or paid via estimated payments. Many people use extra withholding or quarterly estimates to cover the conversion tax.

Remember that Roth conversions do not incur the 10% early withdrawal penalty because they are rollovers, not distributions, but withdrawals of the converted amount within 5 years while under 59½ do incur a 10% penalty on the converted dollars.

Why People Convert To Roth Accounts

1. Tax-free income in retirement

One of the primary advantages of a Roth conversion is the potential for tax-free income in retirement.

Once funds are in a Roth account, qualified withdrawals, including

• Contributions and
• Investment growth

is not subject to federal income tax.

2. Locking in today’s tax rate

A Roth conversion allows you to pay taxes now at your current income tax rate.

This can be especially helpful if you expect your tax rate in retirement to be higher due to changes in income, tax policy, or withdrawal requirements.

3. Avoiding Required Minimum Distributions (RMDs)

Roth IRAs are not subject to required minimum distributions during the original account owner’s lifetime.

4. Tax diversification in retirement

By the way, maintaining both Roth and traditional retirement accounts can provide tax flexibility.

In retirement, you can choose which account to withdraw from based on which option results in the lowest overall tax impact for that year.

5. Taking advantage of lower-income years

A Roth conversion increases your taxable income in the year it’s completed, so the tax cost depends entirely on your marginal tax rate at that time.

So, lower-income years, such as early retirement, job gaps, sabbaticals, or reduced earnings, can create opportunities to convert at lower tax brackets than you would face during peak earning years.

I personally think this approach is most effective in the period between major income phases (e.g., after leaving full-time work but before RMDs or Social Security begin), when taxable income is temporarily reduced.

Traditional 403(b) Vs Roth 403(b)

Traditional 403(b) vs Roth 403(b) — Conversion Rules

Feature	Traditional 403(b)	Roth 403(b)
Tax on contributions	Pre-tax; reduces current taxable income	After-tax; no deduction
Tax on qualified withdrawal	Ordinary income tax	Tax-free (≥59½ + 5-year rule)
Core tax logic	Tax deferred	Tax prepaid
Conversion eligibility	Allowed if plan permits + eligible distribution (in-service or separation)	Not applicable
Conversion type	In-plan Roth conversion or rollover to Roth IRA; taxable event	Not applicable
Tax on conversion	Ordinary income on converted amount	No conversion
Timing constraint	Driven by plan rules + IRS distribution eligibility (not fixed age)	Not applicable
Partial conversion	Allowed if plan allows	Not applicable
Reversibility	Generally irreversible	Not applicable
RMDs	Required starting age 73	None for owner (current law)

Traditional 403(b) vs Roth 403(b) — Conversion Rules

Tax on contributions

Traditional 403(b)

Pre-tax; reduces current taxable income

Roth 403(b)

After-tax; no deduction

Tax on qualified withdrawal

Traditional 403(b)

Ordinary income tax

Roth 403(b)

Tax-free (≥59½ + 5-year rule)

Core tax logic

Traditional 403(b)

Tax deferred

Roth 403(b)

Tax prepaid

Conversion eligibility

Traditional 403(b)

Allowed if plan permits + eligible distribution (in-service or separation)

Roth 403(b)

Not applicable

Conversion type

Traditional 403(b)

In-plan Roth conversion or rollover to Roth IRA; taxable event

Roth 403(b)

Not applicable

Tax on conversion

Traditional 403(b)

Ordinary income on converted amount

Roth 403(b)

No conversion

Timing constraint

Traditional 403(b)

Driven by plan rules + IRS distribution eligibility (not fixed age)

Roth 403(b)

Not applicable

Partial conversion

Traditional 403(b)

Allowed if plan allows

Roth 403(b)

Not applicable

Reversibility

Traditional 403(b)

Generally irreversible

Roth 403(b)

Not applicable

RMDs

Traditional 403(b)

Required starting age 73

Roth 403(b)

None for owner (current law)

Responsive comparison table showing Traditional 403(b) versus Roth 403(b) conversion rules, taxes, eligibility, conversion mechanics, timing, reversibility, and RMD treatment.

Not all 403(b) accounts are taxed the same way.

A traditional 403(b) contains pre-tax money.

Contributions lowered your taxable income when you made them, so the IRS taxes the money when it comes back out.

A Roth 403(b), on the other hand, already contains after-tax contributions. That means the contribution portion has already been taxed.

If you roll a Roth 403(b) into a Roth IRA, there is generally no new income tax triggered on the contributions themselves.

The earnings side, however, still follows Roth distribution rules and timing requirements.

Direct Rollover Vs Indirect Rollover

When you move money from a 403(b) to a Roth IRA, taxes apply on pre-tax amounts.

In my professional opinion, when you are converting a 403(b), a direct rollover is almost always the cleaner option.

Taxes You’ll Owe on the Conversion

You need to pay an upfront tax cost for Roth conversions.

Converting retirement money increases taxable income immediately. Depending on the size of the conversion, this can push you into much higher tax brackets.

Taxes You’ll Owe on 403(b) – Roth IRA Conversion

Tax Type	Applies?	What Happens
Federal income tax	Yes	Converted amount added to taxable income in that year
State income tax	Usually yes	Depends on your state
10% early withdrawal penalty	No	Waived if funds go directly into Roth IRA
Tax withholding	Sometimes	20% may be withheld in indirect rollover
Medicare / Social Security effects	Possible	Higher income may raise premiums or taxable benefits

Taxes You’ll Owe on 403(b) – Roth IRA Conversion

Federal income tax

Applies?

Yes

What Happens

Converted amount added to taxable income in that year

State income tax

Applies?

Usually yes

What Happens

Depends on your state

10% early withdrawal penalty

Applies?

No

What Happens

Waived if funds go directly into Roth IRA

Tax withholding

Applies?

Sometimes

What Happens

20% may be withheld in indirect rollover

Medicare / Social Security effects

Applies?

Possible

What Happens

Higher income may raise premiums or taxable benefits

Responsive table showing taxes you may owe on a 403(b) to Roth IRA conversion, including federal and state income tax, early withdrawal penalty, withholding, and Medicare or Social Security effects.

For example:

• A $50,000 conversion at a 22% bracket could generate roughly $11,000 in federal tax
• A $200,000 conversion at a 24% bracket could create nearly $48,000 in taxes
• Large conversions can even trigger Medicare IRMAA surcharges later on

And that is before even considering state income taxes.

This is why I always recommend my clients for partial Roth conversions spread over multiple years instead of one giant conversion all at once.

Are there No Income Limits On Conversions?

The IRS does not impose income limits on who can convert.

This is very different from normal Roth IRA contributions, which phase out at higher income levels.

Someone earning a very high salary may not be able to contribute directly to a Roth IRA, but they can still convert traditional retirement money into one.

References:

• https://www.fidelity.com/retirement-ira/roth-conversion-checklists
• https://www.westernsouthern.com/retirement/how-roth-ira-conversions-could-fit-into-retirement-planning
• https://www.schwab.com/learn/story/why-consider-roth-ira-conversion-and-how-to-do-it
• https://www.irs.gov/publications/p571