Federal retirees and near-retirees often ask whether the Thrift Savings Plan works the same way as private-sector 401(k) plans when it comes to converting traditional savings into Roth savings. A Roth in-plan conversion TSP comparison is a useful exercise because the rules governing the TSP are not identical to those governing many corporate retirement plans, and understanding the difference can prevent costly assumptions during Retirement Planning.

This article walks through how in-plan Roth conversions typically work, how the TSP actually handles Roth savings today, and what alternative strategies retirees sometimes use to accomplish similar goals.

What Is a Roth In-Plan Conversion?

An in-plan Roth conversion is a feature that some employer retirement plans offer, allowing a participant to move money from a traditional (pre-tax) account into a Roth (after-tax) account without leaving the plan or rolling funds into an outside IRA. The participant pays ordinary income tax on the converted amount in the year of the conversion, and in exchange, future qualified withdrawals from the Roth portion can potentially grow and be withdrawn tax-free.

This type of conversion became more common after federal legislation in 2010 and 2013 expanded the ability of 401(k), 403(b), and 457(b) plans to offer it. Many large private-sector employers added the feature to give employees more flexibility in managing their tax exposure over time.

Does the TSP Currently Offer a Roth In-Plan Conversion?

This is the point where many federal employees and retirees are surprised. As of 2026, the Thrift Savings Plan does not offer an in-plan Roth conversion feature. Participants can contribute to a Roth TSP balance going forward, and the government matches contributions on a pre-tax basis, but there is no mechanism within the TSP itself to convert an existing traditional balance into the Roth balance while keeping the money in the plan.

This distinction matters a great deal in a Roth in-plan conversion TSP comparison, because it means TSP participants cannot do what many corporate 401(k) participants can do directly inside their plan. Anyone comparing the TSP to a private employer plan should not assume the same conversion tools are available.

Roth In-Plan Conversion TSP vs. Private-Sector 401(k) Plans

Below is a side-by-side look at how the two systems generally differ. Keep in mind that private-sector plan rules vary by employer, so not every 401(k) offers this feature either.

Private-Sector 401(k) With In-Plan Conversion Feature

  • Participant can convert traditional balances to Roth without a distribution event, in many cases.
  • Conversion can often be done in any amount, sometimes multiple times per year, depending on plan rules.
  • Taxes owed on the converted amount are typically due in the year of conversion.
  • Money stays under the plan’s investment lineup and fee structure.

Thrift Savings Plan (Current Structure)

  • No in-plan conversion tool exists for traditional TSP balances.
  • Participants can only build a Roth balance through new Roth contributions (and, for civilian employees, agency automatic and matching contributions still go into the traditional side).
  • To convert existing traditional TSP dollars to Roth, a participant generally must move funds out of the TSP entirely.
  • Moving money out means giving up the TSP’s low-cost fund structure unless funds are eventually rolled back in, which has its own restrictions.

Seeing these two columns next to each other makes clear why a straightforward Roth in-plan conversion TSP comparison often ends with a caveat: the “in-plan” part simply is not available within the TSP the way it is in many other plans.

Alternative Paths for TSP Participants Who Want Roth Conversions

Because the TSP does not offer a built-in conversion feature, participants who want to shift traditional dollars into Roth status typically need to look outside the plan. Two common approaches are described below, along with considerations for each.

Rolling Traditional TSP Funds to a Traditional IRA, Then Converting

A separated employee or retiree can roll traditional TSP funds into a traditional IRA and then convert some or all of that IRA balance to a Roth IRA. This achieves a similar tax result to an in-plan conversion, but it happens outside the TSP.

For example, imagine a retired federal employee named Carol who has $300,000 in her traditional TSP. She rolls $150,000 into a traditional IRA, then converts $40,000 of it to a Roth IRA in a single tax year, spreading further conversions across future years to manage her tax bracket. She still has $150,000 remaining in the TSP, which keeps that portion under the TSP’s expense ratios.

This approach requires that the participant already be eligible to withdraw or roll over funds from the TSP, which for many federal employees means having separated from service or reaching a certain age with in-service withdrawal eligibility.

In-Service Withdrawals (Age-Based)

TSP participants who are still working but have reached age 59½ may be eligible for an age-based in-service withdrawal. This allows a portion of the traditional balance to be moved to an IRA while still employed, which some participants then use to begin partial Roth conversions outside the plan. This does not change the fact that no in-plan Roth conversion exists at the TSP level; it simply provides an

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