Federal employees often say “I have FERS” as if it were one thing. It isn’t. FERS is a three-legged retirement system, and almost every retirement mistake I see comes from planning the three legs together when they should be planned separately.

Let me walk through what each leg is, what it does, and why the distinction matters when you’re making decisions.

Leg one: The FERS Basic Benefit Plan (the pension).

This is the defined-benefit annuity I covered in the previous article. OPM calculates it from your high-3 average salary, your years of creditable service, and a multiplier that depends on your age and years at retirement. For most retirements, the multiplier is 1.0% per year. For retirements at age 62 or later with 20+ years of service, it bumps to 1.1% per year. The result is a monthly check you cannot outlive.

The pension is the only one of the three legs that is guaranteed for life. It is also the leg with the most arcane eligibility rules — the Minimum Retirement Age, the MRA+10 retirement, the early retirement age, the special category provisions, the deferred retirement rules. We’ll get to all of those.

Leg two: The Thrift Savings Plan (TSP).

The TSP is a defined-contribution account — the federal equivalent of a 401(k). You contribute a percentage of your basic pay, your agency matches the first 5% (dollar for dollar on the first 3%, 50 cents on the dollar on the next 2%), and the balance grows tax-deferred. You may also contribute to a Roth TSP option, which grows tax-free.

For a federal employee who works a full career, the TSP almost certainly holds more wealththan the pension does. A 30-year FERS employee at the GS-13 step 10 level retiring in 2026, contributing 10% throughout their career and earning a 6% average return, will have a TSP balance well over $1 million in today’s dollars — often several times that.

Unlike the pension, the TSP is yours to manage. You choose the funds (G, F, C, S, I, and the L Funds and Mutual Fund Window). You choose the contribution amount. You choose, eventually, how to draw it down in retirement. The pension gives you one decision a year (your survivor election). The TSP gives you one every day, until you stop making them.

Leg three: Social Security.

Federal employees under FERS pay into Social Security like any other American worker, and they collect it on the same terms — based on their lifetime earnings record and the age they claim.

The FERS pension was deliberately designed smallerthan its CSRS predecessor precisely because the architects of FERS assumed federal employees would also collect Social Security. The full FERS multiplier is 1.0% (or 1.1% with the age-62 bump). The CSRS multiplier was 1.5% to 2.0%. The trade — smaller pension, plus Social Security — was the explicit deal.

Why the three-leg distinction matters in practice.

Each leg has its own rules, its own tax treatment, its own claiming decision, and its own risks. Concretely:

  • The pension has a survivor election that is functionally permanent. The decision is not reversible upward after retirement.
  • The TSPhas a Required Minimum Distribution starting at age 73, a Roth conversion window that closes at a certain point, and an L Fund glide path that doesn’t know your pension exists.
  • Social Securityhas a claiming decision between age 62 and age 70 that, for many federal employees, is worth six figures of lifetime income — and is almost never analyzed alongside the pension it’s paired with.

The cleanest retirement plans I see treat each leg on its own timeline, with its own decision points, then bring the three together to answer the only question that matters: do the three legs add up to the life you want to live?