Top 10 Mistakes Federal Employees Make Before Retirement (and How to Avoid Them)

If you’re within a few years of leaving federal service, it’s easy to feel “mostly ready”… until you hit a surprise. I’ve seen the same federal retirement mistakes cost people months of stress and thousands of dollars. The worst part? Many of these problems are fixable if you catch them early.

This guide is a plain-English rundown of the top 10 mistakes federal employees make before retirement, with simple ways to avoid them. I’ll focus on FERS (Federal Employees Retirement System) since most readers are under FERS, but I’ll also call out key issues for military members and retirees when it matters.

Let’s make your plan boring—in a good way.

Background: The basics of FERS, TSP, Social Security, and FEHB (so the rest makes sense)

Under FERS, your retirement income usually comes from three “legs”:

1. FERS pension (annuity)
   This is your monthly check from the government. It’s based on:

   • Your high-3 average pay (highest 3 years of basic pay)
   • Your years of creditable service
   • A multiplier (usually 1% per year, or 1.1% if you retire at 62+ with 20+ years)

   Official info: OPM Retirement

2. TSP (Thrift Savings Plan)
   This is your 401(k)-style account. Your choices here (funds, contributions, withdrawals, taxes) can make or break your plan.
   Official info: TSP

3. Social Security
   Most FERS employees pay into Social Security and can claim later. Timing matters a lot.
   Official info: SSA

Then there’s FEHB health insurance. For many retirees, keeping FEHB is the biggest financial win in the whole package. But you must meet the rules (more on that below).
Official info: OPM FEHB

If you’re military or a veteran, your plan may also include:

• Military retired pay (handled by DFAS)
• VA disability (not listed in the required sources, but important)
• Buying back active-duty time for FERS credit (a huge decision)

Now let’s get into the mistakes that cause the most pain.

Federal retirement mistakes: The Top 10 (and how to avoid them)

Mistake #1: Waiting too long to check your service history (SCD, deposits, and missing time)

Your retirement calculation is only as good as your records. People often assume HR has everything correct. Sometimes they don’t.

What goes wrong:

• Missing service periods (seasonal, temp, prior civilian time)
• Incorrect Service Computation Date (SCD)
• Unpaid deposits for temporary service (pre-1989 rules can get messy)
• Unpaid military service deposit (the “military buyback”)

How to avoid it:

• Ask HR for your Certified Summary of Federal Service.
• Compare it to your own records: SF-50s, DD-214, old leave and earnings statements.
• If you have military time, request your earnings statement and deposit estimate early.

Start here: OPM Service Credit

Mistake #2: Not understanding the high-3 (and assuming overtime counts)

Your high-3 is based on basic pay, not overtime, bonuses, awards, or most differentials.

Common surprise: A person works tons of overtime in their last 3 years, expecting a bigger pension. But overtime doesn’t increase the high-3.

How to avoid it:

• Look at your basic pay rate history (step increases, grade changes).
• If you’re considering a promotion, understand how it may affect your high-3.

Mistake #3: Retiring at the wrong time of year (and losing money)

Retirement timing can change:

• Your first annuity payment date
• Your leave payout timing
• Your COLA timing (cost-of-living adjustment)
• Your FEHB coverage start in retirement

A classic example: Many employees retire at the end of a pay period or end of the month for smoother pay and benefits processing. It’s not always required, but it often reduces headaches.

OPM guidance and rules vary by situation, so confirm with your HR office and OPM resources: OPM Retirement Center

Mistake #4: Missing the FEHB “5-year rule” (this one is brutal)

To keep FEHB into retirement, you generally must be enrolled in FEHB for:

• The 5 years right before retirement, or
• All the time since your first opportunity to enroll (if less than 5 years)

If you miss this, you may lose the chance to carry FEHB as a retiree. That can mean paying much more for health insurance later.

How to avoid it:

• If you’re within 5 years of retirement, treat FEHB coverage as non-negotiable.
• If you left FEHB to use a spouse plan, re-check your timeline.

Official source: OPM FEHB Eligibility in Retirement

Mistake #5: Underestimating taxes in retirement (TSP + pension + Social Security)

A lot of people assume retirement means “low tax.” Sometimes it does. Sometimes it doesn’t.

Why it can be higher than expected:

• FERS pension is taxable (mostly federal; state depends)
• TSP withdrawals are taxable (traditional TSP)
• Social Security can be partly taxable based on other income
• Required Minimum Distributions (RMDs) can force withdrawals later

IRS basics: IRS Retirement Topics

Mistake #6: Taking Social Security too early without running the math

You can claim Social Security as early as 62, but your monthly amount is reduced for life.

Rule of thumb (not one-size-fits-all):

• If you claim at 62, you get a smaller check.
• If you wait until full retirement age (FRA), you get your full amount.
• If you wait until 70, it grows even more.

Check your estimate: SSA Retirement Benefits

Mistake #7: Treating the TSP like a savings account (no plan for withdrawals)

TSP is great at helping you save. But the hard part is spending it.

Common TSP planning errors:

• No withdrawal plan (monthly needs vs. taxes)
• Pulling too much early and “front-loading” taxes
• Ignoring investment risk right before and after retirement
• Forgetting beneficiary updates

Official withdrawal info: TSP Withdrawals

Mistake #8: Not planning for Medicare and FEHB together

Many retirees keep FEHB and also enroll in Medicare Part A (usually premium-free if you qualify). Part B costs extra, and the decision depends on your health, budget, and risk tolerance.

Medicare official source: CMS Medicare

What goes wrong:

• People skip learning about Part B until the last minute
• They miss enrollment windows and face late penalties
• They don’t understand how FEHB and Medicare coordinate

Mistake #9: Forgetting survivor benefits (and leaving a spouse exposed)

This is one of the most emotional mistakes because you often can’t fix it later.

For FERS:

• If you want a spouse to keep FEHB after you die, you usually need to elect a survivor benefit.
• Survivor benefits reduce your pension while you’re alive, but protect your spouse later.

OPM overview: OPM Survivor Benefits

Mistake #10: Not using military time correctly (buyback, reserve time, and double-dipping rules)

If you have active-duty military time, you may be able to “buy it back” to count toward your FERS pension.

But watch the trade-offs:

• If you’re a military retiree, buying back active-duty time can require waiving military retired pay (with some exceptions). This is a big decision.
• Reserve retirement rules can be different.

Start with official pay sources: DFAS and retirement basics at OPM

If you want more on this topic, FedInfo readers often like: military service credit deposit basics and how military time affects federal retirement.

Common FERS mistakes that show up right before retirement (and why they happen)

Here’s the pattern behind many common FERS mistakes: people focus on the pension number and ignore the “edges” that make retirement work day-to-day.

Misconceptions to watch for:

• “My high-3 includes overtime.” (Usually no.)
• “HR will catch any errors.” (Sometimes they don’t.)
• “I’ll just take Social Security at 62 because everyone does.” (That can lock in a smaller check.)
• “I’ll figure out TSP withdrawals later.” (Later often becomes rushed and expensive.)
• “FEHB will just continue automatically.” (Only if you meet the rules and retire on an immediate annuity.)

If you remember nothing else: small paperwork issues can cause big delays. And delays can mean months of reduced income while OPM finalizes your case.

Practical examples with real numbers (so you can see the math)

Let’s walk through a few real-world scenarios. These are simplified, but they’re close enough to help you plan.

Example 1: FERS pension estimate (1% vs 1.1% multiplier)

Scenario: GS-12 retires with 30 years of service. High-3 basic pay is $98,000.

If retiring before 62 (1% multiplier):

• Pension = 1% × high-3 × years
• = 0.01 × $98,000 × 30
• = $29,400 per year
• = $2,450 per month (before taxes and deductions)

If retiring at 62+ with 20+ years (1.1% multiplier):

• Pension = 1.1% × $98,000 × 30
• = 0.011 × $98,000 × 30
• = $32,340 per year
• = $2,695 per month

Difference: about $245/month for life. That’s real money.

Source for formula basics: OPM FERS Computation

Example 2: Military buyback rough math (why waiting can cost more)

Scenario: You did 4 years active duty and became a FERS employee later.

A common rule of thumb: the deposit is about 3% of your basic military pay (for FERS), plus interest if you wait beyond the interest-free window.

Let’s use a simple estimate:

• Average basic pay during active duty (rough estimate): $28,000/year
• 4 years total basic pay: $28,000 × 4 = $112,000
• Deposit estimate: 3% × $112,000 = $3,360

If you delay for years, interest can add hundreds or more, depending on rates and timing. That’s why people who wait until the last year often say, “I wish I did this earlier.”

Start point: OPM Creditable Service and military pay records at DFAS

Example 3: Social Security timing (simple break-even thinking)

Scenario: Your SSA estimate says:

• At 62: $1,800/month
• At 67 (FRA): $2,600/month

Difference: $800/month.

If you take it at 62, you get 5 extra years of payments:

• $1,800 × 60 months = $108,000 collected by age 67

But after 67, the higher check starts to catch up:

• Extra $800/month = $9,600/year

Break-even time:

• $108,000 ÷ $800 ≈ 135 months, or about 11.25 years
• That means around age 78 is a rough break-even point in this simplified example.

This is not perfect math (taxes, COLAs, spouse benefits matter), but it shows why “everyone takes it at 62” is not a plan.

Check your numbers: SSA.gov

Example 4: TSP withdrawal and taxes (why “just take $60k” can sting)

Scenario: You retire and want $60,000 from traditional TSP this year, on top of:

• FERS pension: $30,000
• Part-time work: $15,000

Total taxable income (very simplified, before deductions):
$60,000 + $30,000 + $15,000 = $105,000

That may push part of your income into higher tax brackets and increase how much of your Social Security is taxable later. The point isn’t the exact bracket—it’s that stacking income sources can create a surprise tax bill.

Helpful official info: IRS retirement plan distributions

If you want to go deeper on TSP strategy, you might also like: TSP withdrawal options explained.

Federal retirement planning errors: two big “angles” people miss

Angle 1: Paperwork delays can hit your income right away

OPM retirement processing can take time. Some retirees receive interim payments that are smaller until the final calculation is done.

What you can do:

• Submit a clean, complete package
• Confirm your service history early
• Keep copies of everything (SF-50s, military docs, marriage certs if needed)

Official retirement hub: OPM.gov

Angle 2: Your “retirement paycheck” is really 4 systems working together

Your plan isn’t just one number. It’s:

• Pension start date and deductions
• TSP withdrawal plan
• Social Security timing
• Health insurance (FEHB + Medicare choices)

When people run into trouble, it’s often because one system didn’t line up with the others. Example: retiring before you’re eligible for an immediate annuity can affect FEHB carryover. Or taking large TSP withdrawals can raise taxes and change Medicare premium brackets later.

For ongoing federal retirement news and rule changes, these are solid sources:

• FedWeek
• Government Executive
• Federal Times
• Military.com

Retirement checklist federal: Step-by-step guide (use this 12–24 months out)

Use this as your simple retirement checklist federal employees can actually follow. Print it. Put dates next to items.

Step 1 (24–18 months out): Get your numbers and records

• Request your retirement estimate from HR.
• Get your Certified Summary of Federal Service.
• Gather:
  • Last 3 years of SF-50s
  • Marriage certificate/divorce decrees (if survivor benefits apply)
  • Military DD-214 and earnings (if buying back time)

Step 2 (18–12 months out): Decide on the big “forever” choices

• Pick a target retirement date (end of pay period is often simplest).
• Decide if you will:
  • Elect a survivor benefit (and which level)
  • Keep FEHB (confirm 5-year rule)
  • Enroll in Medicare Part A and/or Part B later

Medicare basics: CMS.gov

Step 3 (12–6 months out): Build your income plan (pension + TSP + SSA)

• Estimate monthly spending in retirement (housing, food, insurance, travel).
• Map income sources:
  • FERS monthly pension (net after FEHB and taxes)
  • TSP planned monthly withdrawal (start conservative)
  • Social Security start age (run at least 2 claim-age options)

Tools and info:

• TSP.gov
• SSA.gov

Step 4 (6–3 months out): Clean up benefits and beneficiaries

• Update beneficiaries for:
  • TSP
  • FEGLI (if you have it)
  • Any life insurance or accounts outside work

People forget this step a lot. And it matters.

Step 5 (3–0 months out): Submit, confirm, and keep copies

• Submit retirement paperwork through your agency.
• Confirm FEHB enrollment status and plan choice.
• Keep a full copy of your retirement packet at home.

OPM info center: OPM.gov

Key takeaways / Bottom line (what to do next)

Most federal retirement planning errors come from waiting too long, guessing on rules, or skipping the “boring” details like FEHB eligibility, service credit, and survivor elections. The fix is simple: start earlier than you think, verify your records, and make a clear plan for TSP and Social Security.

If you’re within 2 years of retirement, your best next move is to follow the checklist above and schedule time with HR to confirm your service and benefits. A little effort now can prevent years of regret later.