W-4R Form TSP Withholding: How to Set Tax Withholding on TSP Distributions

What Is Form W-4R and When Does It Apply?

If you've already filled out a W-4P to adjust withholding on your OPM annuity, you might assume TSP withdrawals work the same way. They don't. The IRS uses a completely separate form — the W-4R — for what it calls "nonperiodic payments and eligible rollover distributions." In practical terms, that means every TSP payment that isn't a life-annuity or an installment stream lasting 10 years or more.

Here's the split: Form W-4P governs your monthly OPM annuity (periodic payments). Form W-4R governs TSP lump-sum withdrawals, partial withdrawals, and short-duration installment payments. In-plan Roth conversions are taxable, but the TSP does not permit withholding from them.

Default Withholding Without a W-4R

If you request a TSP distribution and don't submit a W-4R, the default withholding rate depends on the type of payment:

• Eligible rollover distributions (lump sums, partial withdrawals, installments under 10 years): Mandatory 20% federal withholding if the money is paid directly to you rather than rolled over trustee-to-trustee.
• Non-rollover-eligible distributions (installments of 10+ years, required minimum distributions): Default 10% withholding unless you elect a different rate.

That mandatory 20% on indirect rollovers is the one that catches retirees off guard. If you take a $50,000 partial withdrawal paid directly to you, the TSP sends $40,000 to your bank and $10,000 to the IRS — even if you plan to roll the full $50,000 into an IRA within 60 days. To complete that rollover, you'd need to come up with $10,000 from personal savings to deposit into the IRA, then wait to recover the withheld amount when you file your tax return.

How to Complete Form W-4R for TSP Distributions

The W-4R is short — just one page of elections. Here's what matters:

Step 1: Choose your withholding rate. For payments that are NOT eligible rollover distributions, you can elect any rate from 0% to 100%. The form includes a marginal rate table to help you estimate. Add up your other retirement income sources (OPM annuity, Social Security, part-time wages) and use the table to find your likely marginal federal tax bracket. That bracket rate is usually a reasonable withholding election.

Step 2: Apply it to the right distribution type. For eligible rollover distributions paid directly to you, the 20% minimum is mandatory — you can elect more than 20% on the W-4R, but not less. The only way to avoid the 20% entirely is to use a direct rollover (trustee-to-trustee transfer), which bypasses withholding altogether.

Step 3: Submit through your TSP account. You can update your withholding election through the TSP's online withdrawal wizard at tsp.gov or by calling the ThriftLine at 1-877-968-3778. A new W-4R election applies to future distributions — it won't retroactively change withholding on payments already processed.

W-4R for In-Plan Roth Conversions

Starting January 28, 2026, the TSP allows traditional-to-Roth in-plan conversions. Here's the wrinkle: the TSP does not withhold taxes on in-plan Roth conversions. The converted amount stays entirely within your TSP account, but the IRS treats the conversion as taxable ordinary income for the calendar year.

That means you can't use a W-4R to have the TSP cover the conversion's tax bill. You'll need to pay the resulting income tax from outside funds — a checking account, savings, or by increasing withholding on your other income streams (bumping your W-4P withholding on your OPM annuity, for example). The resulting tax must be planned for separately because no automatic TSP withholding covers it.

Coordinating W-4R with Your Other Withholding Forms

Federal retirees juggling multiple income streams often end up managing three different withholding forms:

The IRS doesn't coordinate withholding across these three payers for you. Each payer withholds based solely on the form you gave them, with no knowledge of your other income. That's why many retirees end up underwithholding in their first year — each payer withholds as if its payment is your only income, when in reality three or four income streams are stacking on top of each other.

If you'd rather not file quarterly estimated payments, the simplest fix is to pick one payer — usually OPM via the W-4P, since it's the most consistent monthly payment — and set it to withhold extra to cover the combined tax on all your income sources. Then set the W-4R and W-4V to lower or zero rates to avoid double-withholding. Alternatively, work through the marginal rate tables on all three forms to split withholding proportionally.

Our Federal Retirement Tax toolkit includes a Withholding Coordination Worksheet that walks you through this calculation across all three payers, so you can hand your CPA the completed worksheet instead of paying them to reconstruct it from scratch.

Common W-4R Mistakes to Avoid

Leaving the default when it doesn't fit. The 20% default on lump-sum withdrawals is often too low for retirees in the 22% or 24% bracket once all income sources are combined. And the 10% default on RMDs is almost always too low if you're collecting an annuity and Social Security alongside.

Forgetting state taxes. The W-4R only covers federal withholding. If your state taxes TSP distributions (most do), you'll owe state income tax separately. Some states allow you to request state withholding through the TSP; others require quarterly estimated payments to the state directly.

Not updating after major changes. A new Social Security filing, a Roth conversion, or a spouse starting their own retirement income all change your combined tax picture. Revisit your W-4R election whenever your total household income shifts meaningfully.