The Thrift Savings Plan allows federal employees to contribute in two different ways: traditional or Roth.
Both options help you save for retirement, but they are taxed differently. Understanding the difference can help you decide how to balance taxes now versus taxes later.
How traditional TSP contributions work
Traditional TSP contributions are made with pretax money, meaning you are not taxed for the contribution until you withdraw it, providing a tax benefit upfront.
This means contributions reduce your taxable income in the year you make them. The tax benefit happens upfront.
How Roth TSP contributions work
Roth TSP contributions are made with after-tax money.
You do not get a tax break when you contribute. Instead, the benefit comes later. Qualified Roth TSP withdrawals in retirement can be tax-free.
Because of this, Roth contributions are often used by people who expect to be in a similar or higher tax bracket later in life.
Contribution limits apply to both
TSP contribution limits apply regardless of whether contributions are traditional or Roth.
You can split your contributions between the two types, but the total amount you contribute in a year cannot exceed the annual limit.
Our TSP contribution limits page explains how these limits work and how catch-up contributions apply.
Taxes now vs. taxes later
The main difference between traditional and Roth TSP contributions comes down to timing.
With traditional contributions, you save on taxes today and pay taxes later. With Roth contributions, you pay taxes today, and withdrawals of earnings are tax-free only when the withdrawal is a qualified distribution under IRS rules; a nonqualified withdrawal may include taxable earnings.
Neither option is better in every situation. The right choice depends on factors like:
- Current income and tax bracket
- Expected income in retirement
- Other taxable and tax-free income sources
Using both traditional and Roth contributions
Many federal employees use a mix of traditional and Roth contributions.
Having both account types available in retirement can provide some flexibility that allows retirees to choose which accounts to withdraw from based on tax and income needs in any given year, or to manage taxes over time rather than locking into a single strategy.
If you decide to choose only one, consider how it will blend with your pensions, Social Security, and other savings. To see how all of these pieces fit together, visit our Federal Retirement Benefits Overview, which explains how federal retirement income sources work as a system.
For a broader look at how tax treatment affects income planning, our Retirement Income Strategies Overview page explains how retirees commonly combine different income sources.
Tax Note: This article discusses general tax concepts for educational purposes only and is not legal, tax, or investment advice. Tax treatment depends on your individual circumstances and current law, which can change. Consult your own attorney, tax advisor, or financial professional before making decisions about contributions, withdrawals, conversions, or retirement income. See IRS guidance on designated Roth accounts at irs.gov for the qualified-distribution rules in effect.
