FERS, Social Security, and TSP: Your 3 Retirement Income Streams

Last Updated: March 22, 2026 Reading Time: 11 min

Federal retirement was designed as a three-legged stool: your FERS pension, Social Security, and TSP. No single leg is meant to fund retirement on its own. Most federal employees don't know how the three work together, or how much each one actually provides.

Here's the math, with real 2026 numbers, so you can see exactly where you stand.

Key Takeaways

• FERS + Social Security alone replace only 55-60% of your pre-retirement income. TSP fills the 20-25% gap needed to reach the 80% target.
• The 1.1% FERS multiplier (age 62+ with 20 years) gives you a permanent 10% pension boost. One extra year of work at the right time can mean $75,000+ in additional lifetime pension income.
• WEP does NOT apply to FERS employees. It never did, and it was repealed entirely in 2025.
• The FERS Supplement bridges your income from early retirement to age 62, but it gets no COLA and ends at 62 regardless of when you claim Social Security.
• Contributing only 5% to TSP (just enough for the full match) likely leaves you short. Most employees need 10-15% to hit their retirement target.

Leg 1: Your FERS Pension

The Formula

Your annual FERS pension is:

High-3 Average Salary x Years of Service x Multiplier

The multiplier is 1% for most retirees. It jumps to 1.1% if you retire at age 62 or older with at least 20 years of creditable service.

Your high-3 is the highest average basic pay over any consecutive 36 months of service. It doesn't have to be your final 3 years, and it excludes overtime, bonuses, and most special pays.

Use our High-3 Calculator to find your exact high-3 average.

The 1.1% Multiplier: A Decision Worth $75,000+

This one number is the single most valuable threshold in FERS retirement planning.

Scenario	High-3	Years	Multiplier	Annual Pension
Retire at 61 with 30 years	$120,000	30	1.0%	$36,000
Retire at 62 with 30 years	$120,000	30	1.1%	$39,600
Difference				$3,600/year

Over a 25-year retirement, that extra year of work at age 62 generates roughly $90,000 in additional pension income. Both conditions must be met: age 62 and 20+ years.

FERS COLAs

FERS retirees under 62 receive no COLA on their pension. COLAs begin at 62, but they're reduced compared to Social Security:

Inflation Rate	FERS COLA	Social Security COLA
2% or less	Full match	Full match
2-3%	Capped at 2.0%	Full match
Over 3%	Inflation minus 1%	Full match

In 2026, inflation was 2.8%. FERS retirees got a 2.0% COLA. Social Security and CSRS retirees got 2.8%.

Leg 2: Social Security

FERS Employees Pay Into Social Security

Unlike CSRS employees, FERS employees pay the full 6.2% Social Security payroll tax. You earn Social Security credits through your federal career just like any private-sector worker.

WEP does NOT apply to FERS employees. This is the most persistent misconception in federal retirement. The Windfall Elimination Provision was designed for workers who split careers between Social Security-covered and non-covered employment. FERS employees are covered workers. WEP never applied to you.

WEP was also fully repealed by the Social Security Fairness Act (signed January 5, 2025), so it no longer applies to anyone, CSRS employees included.

When to Claim

Claiming Age	Effect	2026 Maximum Benefit
Age 62	30% permanent reduction	$2,969/month
Age 67 (FRA)	100% of your benefit	$4,207/month
Age 70	124% of FRA benefit	$5,181/month

For every year you delay past your full retirement age (67 for those born 1960+), your benefit increases 8% permanently. That's guaranteed, inflation-adjusted income growth that's hard to beat anywhere else.

The Smart Play for Most Feds

Most federal employees should not claim Social Security at 62, even though the FERS Supplement ends then. A better sequence:

1. Retire at MRA, collect your pension + FERS Supplement
2. Supplement ends at 62. Use TSP withdrawals to bridge to age 67 (or 70)
3. Claim Social Security at 67 or 70 for the permanently higher benefit

The break-even point for delaying from 62 to 67 is around age 79-81. If you're in reasonable health, the delay pays off.

Leg 3: Your TSP

Why TSP Can't Be Optional

FERS + Social Security combined replace approximately 55-60% of pre-retirement income for a 30-year employee. The standard retirement planning target is 80%. TSP fills the gap.

Without adequate TSP savings, you'll either need to work longer, accept a lower standard of living, or find other income sources.

The Match: Don't Leave Money on the Table

Your Contribution	Agency Contribution	Total Going In
0%	1% (automatic)	1%
3%	1% + 3% match = 4%	7%
5%	1% + 4% match = 5%	10%
10%	1% + 4% match = 5%	15%

The agency match maxes out when you contribute 5%. Below that, you're leaving free money behind. But 5% isn't enough for most employees to hit their retirement target. Financial planners recommend 10-15% for federal employees, depending on years to retirement.

The front-loading trap: If you max out the $24,500 annual limit too early in the year (by contributing a high percentage), you could miss agency matching in the months when you've already hit the cap. Spread contributions evenly across all pay periods.

2026 Contribution Limits

Category	Annual Limit
Standard (all ages)	$24,500
Age 50+ catch-up	+$8,000 = $32,500
Ages 60-63 super catch-up	+$11,250 = $35,750

If your wages exceed $150,000, catch-up contributions must be Roth.

The FERS Supplement: Your Bridge to 62

If you retire before 62 with an immediate, unreduced annuity (MRA + 30 years, or age 60 + 20 years), you receive the FERS Supplement. It approximates the Social Security benefit earned during your FERS service.

How It's Calculated

Social Security estimate at 62 x (FERS civilian years / 40)

Example: $2,000/month SS estimate x (30 years / 40) = $1,500/month

Log into ssa.gov/myaccount to find your age-62 estimate.

Three Things Most People Miss

1. It gets no COLA. The supplement is frozen at the amount calculated at retirement. Five years of 2% inflation erodes about 10% of its purchasing power.

2. It has an earnings test. If you earn more than $24,480 (2026 limit) from wages or self-employment, OPM reduces your supplement by $1 for every $2 over the limit. Investment income, TSP withdrawals, and rental income don't count.

3. MRA+10 retirees don't get it. Retire at MRA with between 10 and 29 years of service, and you are NOT eligible for the supplement. That 30th year of service can be worth $1,000-$1,500/month for 5+ years.

How the Three Legs Add Up: Real Numbers

Scenario: GS-13 Step 10, Retiring at 62 with 30 Years

Income Source	Annual Amount	% of $120K Salary
FERS pension (1.1% x $120K x 30)	$39,600	33%
Social Security at 67	~$24,000	20%
TSP withdrawals (4% of $720K)	$28,800	24%
Total	$92,400	77%

Close to the 80% target, but requires a $720,000 TSP balance.

Scenario: Same Employee, Only 5% TSP Contribution

An employee contributing only 5% (the minimum for full match) throughout their career might retire with $350,000 in TSP instead of $720,000.

Income Source	Annual Amount	% of $120K Salary
FERS pension	$39,600	33%
Social Security at 67	~$24,000	20%
TSP withdrawals (4% of $350K)	$14,000	12%
Total	$77,600	65%

That's a $14,800/year shortfall from the 80% target, every year of retirement.

The "Gap Years" Problem (Ages 62-67)

If you retire at MRA (57) and delay Social Security to 67:

Retirement Phase	Annual Income	What's Missing
Ages 57-62	$82,800	Pension + Supplement + TSP
Ages 62-67	$64,800	Supplement ends, SS not started
Ages 67+	$88,800	All three legs active

Ages 62-67 are the tightest years. Plan your TSP withdrawals to cover this gap before deciding to delay Social Security.

Estimate Your Retirement Income

Use our free FERS Retirement Calculator to model your pension under different retirement ages and years of service. Then use the TSP Calculator to project your savings growth.

Try the FERS Calculator now

Tax Treatment: What You'll Actually Keep

All three income streams are taxable, but differently:

Source	Federal Tax Treatment
FERS Pension	~95% taxable (small after-tax portion recovered over time)
Social Security	Up to 85% taxable for most federal retirees
TSP Traditional	100% taxable as ordinary income
TSP Roth	Tax-free (if held 5+ years and age 59.5+)

These sources stack. Your FERS pension pushes you into a bracket, Social Security adds on top, and TSP withdrawals go on top of that. Many federal retirees are surprised to find themselves in the 22% or 24% bracket in retirement.

That stacking is why Roth TSP contributions and the new Roth in-plan conversion (available since January 28, 2026) deserve serious consideration, especially if you're still in the 22% bracket now.

Frequently Asked Questions

Does WEP apply to FERS employees?

No. WEP never applied to standard FERS employees because they pay Social Security taxes throughout their career. WEP was also repealed entirely by the Social Security Fairness Act, signed January 5, 2025, retroactive to January 2024. This remains one of the most common misconceptions in federal retirement.

What percentage of my salary do FERS and Social Security replace?

For a typical 30-year FERS employee, the pension replaces about 30-33% of pre-retirement income and Social Security adds another 20-25%. Combined, that's roughly 55-60%. Financial planners recommend 80%, which means TSP needs to fill the remaining 20-25% gap.

What is the 1.1% FERS multiplier and how do I get it?

The standard FERS pension formula uses a 1% multiplier. Retire at age 62 or older with at least 20 years of creditable service, and the multiplier increases to 1.1%. That's a permanent 10% pension boost. For a $120,000 high-3 with 30 years, the difference is $3,600 per year for life.

How much should I have in my TSP at retirement?

Federal employees generally need 6-8x their final salary in TSP to reach the 80% income replacement target. For a GS-13 retiring with a $120,000 high-3, that means roughly $720,000 to $960,000. Using the 4% withdrawal rule, $720,000 generates about $28,800 per year.

What happens to the FERS Supplement at age 62?

The FERS Supplement ends on the last day of the month you turn 62, regardless of whether you've claimed Social Security. It receives no COLA adjustments, so it loses purchasing power each year. Plan for the gap between the supplement ending and your Social Security start date.

Related Resources

• FERS Retirement Calculator: Model your pension at different retirement ages
• TSP Growth & Withdrawal Calculator: Project your TSP balance and withdrawal income
• High-3 Calculator: Find your highest 36-month average salary
• FERS Retirement Guide: Full FERS reference
• FERS Supplement Earnings Limit 2026: Deep dive on the earnings test
• Best Dates to Retire 2026: Maximize leave payout and pension start date
• TSP 2026 Changes Overview: What changed for TSP this year

Sources: OPM.gov, SSA.gov, TSP.gov, IRS.gov