Field Guide
Every field, without the wall of text.
Skim the summary, jump to the section you need, and expand only the entries you care about.
Common fields
Jump straight to the inputs people tend to check first.
Sections
Showing 45 of 45 fields in All sections
Setup
Calculator-level choices that shape the household, tax jurisdiction, and comparison mode.
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Scenario name A label for this scenario used in navigation and exports. It has no effect on any calculation — pick anything that helps you distinguish this scenario from others you create.
What it means
This is the label attached to the scenario in navigation, comparisons, and exports. It never changes the math.
Good default
Use a date, milestone, or plain-language description such as "Retire 2028" or "MRA + 10 with partial survivor" so you can recognize it later.
Why it matters
Clear names make it easier to compare scenarios and keep exported reports straight when you are testing multiple retirement dates.
Filing state The state where you'll file income taxes in retirement. This drives FERSCalc's state tax calculation — the model applies 2025 bracket rules and the state's treatment of FERS pension, TSP distributions, and Social Security for your selected jurisdiction. Local city, county, and municipal income taxes are not modeled anywhere, including Maryland's county tax, so your real tax is higher wherever one applies. If you plan to relocate after retiring, choose the state you'll live in, not where you work now.
What it means
This drives FERSCalc’s state income-tax rules for pension income, TSP withdrawals, Social Security, and brackets in retirement.
How to choose it
Pick the state you expect to live in after retirement, not necessarily the state where you work today. A move can change after-tax cash flow materially.
What is excluded
Local city, county, and municipal income taxes are not modeled anywhere, so your real tax is higher wherever one applies. Maryland is the largest case: every county levies 2.25%–3.30% on Maryland taxable income and none of it is included.
Add spouse / partner
What it unlocks
Turning this on adds Person B’s own timeline, balances, and income sources, and switches the tax model to a joint household view.
Who it is for
Use it whether your spouse or partner is federal or not. Person B can be modeled as a non-federal household member with their own retirement resources.
Why it matters
Survivor analysis, joint tax brackets, household Social Security timing, and combined cash flow all depend on the second person being present.
Compare two retirement dates Creates a parallel Scenario B that mirrors all your inputs but uses a different retirement date. The Results Compare tab then shows a break-even analysis of retiring earlier vs. later. All other inputs — salary, TSP, Social Security — stay identical between the two scenarios.
What it does
Creates a Scenario B that copies all inputs except Person A’s retirement date so you can isolate timing effects cleanly.
Best use case
Run this when you are deciding between two plausible retirement dates, such as MRA versus age 60 or one year of extra service versus leaving sooner.
Why it matters
This is often the fastest way to see the break-even tradeoff between more working income now and a different pension path later.
Scenario B retirement date Person A's retirement date in Scenario B. Everything else is identical to Scenario A. The comparison shows which date results in more cumulative household income over time, and at what point the curves cross — the break-even year.
What it means
This is Person A’s retirement date for the alternate comparison scenario. Every other input remains aligned with Scenario A.
How to use it
Try dates that meaningfully change eligibility, service credit, or High-3 timing rather than dates that are only a few days apart.
Why it matters
The comparison view then shows cumulative income, checkpoint deltas, and break-even timing for the two retirement choices.
Identity & Timeline
Dates and coverage settings that determine eligibility, service credit, and the pension formula.
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Date of birth Used to calculate your Minimum Retirement Age (MRA), your age at retirement, and whether you qualify for the 1.1% pension multiplier (age 62 with 20+ years of service). Required for any projection. Enter it exactly as it appears on your government ID.
What it drives
Birth date determines your Minimum Retirement Age, your age at retirement, and whether the 1.1% multiplier applies at 62 with at least 20 years.
How precise to be
Enter the exact date, not just the year. Several rules change at specific birthdays rather than at the start of a calendar year.
Why it matters
Without it, FERSCalc cannot classify your retirement type or apply age-based pension, supplement, and Social Security timing logic.
Federal service start The legacy single-period assumption for your federal civilian Service Computation Date (SCD). It is used only when you do not add a detailed service record. Find it on your most recent SF-50 (box 31, Service Comp. Date); it should not be a private-sector start date or an uncredited military entry date.
What it means
This is the legacy single-period assumption for your federal civilian Service Computation Date. It combines with the separation date only when you do not add a detailed service record.
Where to find it
Use the official SCD from your SF-50, not a military entry date, private-sector date, or the start date at your current agency unless they are the same.
Watch for
If you have breaks, part-time periods, 6C coverage, or service that requires a deposit/redeposit, use the detailed record instead. Confirm military deposits and the official SCD with your agency.
Detailed service record Use dated periods when you have breaks, civilian or military service, part-time schedules, regular versus 6C coverage, or service that is excluded until a deposit or redeposit is resolved. FERSCalc uses OPM's 30-day month / 360-day year convention, freezes credit at separation, and uses entered actual/full-time hours for part-time proration when available; schedule percentage is the transparent fallback. Military service can add formula credit but cannot satisfy the five-year civilian-service minimum. Confirm your record and any deposit status with your agency before relying on it.
What it drives
Each period can record its first and last service day, civilian or military kind, regular or 6C coverage, actual/full-time hours, scheduled work percentage, and whether the period is creditable now. These periods replace the single-start-date assumption.
How FERSCalc counts it
The model uses OPM’s 30-day month and 360-day year convention, adds separately creditable periods, freezes them at separation, and drops remaining days from the annuity factor. Part-time time remains eligibility service; entered actual/full-time hours drive OPM-style proration and schedule percentage is the planning fallback. Military credit does not satisfy the five-year civilian-service minimum.
Confirm before relying
A required deposit/redeposit or refunded FERS period is excluded until resolved. The calculator does not adjudicate deposits, excess LWOP, intermittent service, military credit, or an agency record correction.
Target retirement date The date you plan to separate from federal service. FERSCalc freezes eligibility service and High-3 on this date, then computes immediate, MRA+10, deferred, or not-vested status. Use it to explore how a few extra months of service changes a threshold; it is not automatically the first day pension payments begin.
What it drives
This is the main separation date that freezes service length and High-3, determines eligibility type, and helps determine whether SRS is available. It is not necessarily the pension start date.
Best use
Use it to test meaningful thresholds such as reaching 20 years, crossing age 60 or 62, or moving from MRA+10 to an unreduced pension.
Why it matters
Small changes here can create step-change results because the rules are threshold-based, not perfectly smooth.
Annuity commencement choice For FERS retirement rules, an age is reached the day before the birthday. A supported immediate annuity normally begins the first day of the month after separation. MRA+10 and deferred records may let you choose a later first-of-month legal start, which can reduce or sometimes eliminate the MRA+10 age reduction without adding service or High-3. A delayed start must be at least two days before the 62nd birthday; a birthday on the first or second can still leave a one-month reduction. This is a planning model of the supported voluntary paths; confirm the final election with OPM or your agency.
Immediate annuity
For FERS retirement rules, an age is attained the day before the birthday. For the supported voluntary FERS immediate paths, the annuity normally begins on the first day of the month after separation. The service record and High-3 remain frozen on the separation date.
MRA+10 and deferred choices
MRA+10 and eligible deferred records can use a later first-of-month legal start at least two days before the 62nd birthday. The permanent MRA+10 reduction is based on full months before that birthday; a later start can reduce it and usually eliminate it, but birthdays on the first or second can retain a one-month reduction.
Confirm the final election
The app models the supported voluntary paths only. Verify the retirement authority, commencement date, and insurance effects with your agency or OPM before filing.
FERS coverage Determines which FERS pension formula and employee payroll-contribution rate apply to you. Most employees are auto-detected from their service start date. Select 6C manually if you're in law enforcement, firefighting, air traffic control, or another special-category position — this uses the corresponding special-group payroll rate and unlocks earlier retirement eligibility and the special pension formula.
What it means
This determines the employee payroll-contribution rate and pension formula. Special-category coverage uses the corresponding special-group rate and can provide earlier retirement eligibility and the tiered 6C formula.
Default behavior
Standard FERS tiers are inferred from service start date. You only need to step in manually when you are under 6C or another special category.
Why it matters
Special-category coverage can materially change retirement age, pension formula, and paycheck-side contribution assumptions.
Salary & High-3
Inputs that affect pension size and working-pay comparisons, plus optional current LES reference details.
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Current annual salary Your current annual base pay is the projection's starting taxable wage through separation. It drives working-year federal and state taxes, FICA or applicable payroll contributions, employee retirement-plan contributions, any applicable federal agency TSP contribution, and paycheck comparisons. Your entered High-3 remains the pension baseline; when you set a positive salary-growth assumption, FERSCalc also uses this salary path to project a later High-3.
What it does
This is used for the working-versus-retirement paycheck comparison. When a non-zero Annual salary growth rate is configured, it also serves as the base salary for projecting your High-3 and pre-retirement TSP contributions.
When to enter it
Add it when you care about the Paycheck Bridge or the continuing-work baseline. It is also required when you want the salary growth rate to project your High-3 forward — without a current salary, the entered High-3 is used unchanged.
What number to use
Use current gross annual pay before deductions. For most GS employees, this is the salary shown on the LES or SF-50.
High-3 average salary The average of your highest 3 consecutive years of basic pay — the most important number in the FERS pension formula. For GS employees, basic pay is your base rate plus locality pay (OPM includes locality-based comparability payments in basic pay for retirement purposes); it excludes bonuses, overtime, and awards. Find it by averaging the total annual pay figures from your last three annual SF-50s (box 20, Annual Salary), or ask your HR office.
What it drives
High-3 is the pension base. The formula is High-3 multiplied by service years and the applicable pension multiplier.
What counts
Basic pay includes locality pay for retirement purposes, but not bonuses, overtime, awards, or premium pay.
Where to find it
Average the annual salary figures from your last three annual SF-50s or use an HR-provided estimate if you have one.
Annual salary growth rate
What it does
When set above 0%, the calculator compounds your current salary year-over-year before retirement and uses the resulting three-year average as your projected High-3. TSP contributions in pre-retirement years are also based on the grown salary.
When to use it
Set this when you expect step increases, promotions, or locality-pay adjustments and want a forward-looking High-3 rather than today's number. Leave it at 0% to treat your entered High-3 as the definitive figure.
What number to use
The default of 2.5% approximates federal General Schedule step-increase pace. You can lower it to reflect a GS-15 step-10 ceiling, or raise it if you anticipate a promotion in the next few years.
Important limit
The projection applies growth only to salary entered as "Current annual salary." If you are fewer than three years from retirement, the calculator falls back to your entered High-3 unchanged.
Biweekly net pay Your actual Person A take-home per pay period from your most recent Leave and Earnings Statement (LES), after all deductions. Used only as a current-paycheck anchor in clearly labeled results-side working comparisons; it does not replace projected household net cash flow. You can pair it with the optional current LES details to record recognizable deduction lines as a reference.
What it does
This gives the working-side comparison a real paycheck anchor by using your actual take-home pay from the latest LES.
Where to find it
Use the net pay line from your current LES. It represents after-deduction take-home for one biweekly pay period.
Why it matters
It makes the Paycheck Bridge and working baseline more intuitive because the comparison starts from what actually lands in your account now.
Current Person A LES details Optional biweekly lines from Person A's current LES, such as FEGLI, FEHB, FERS retirement, TSP savings, and federal or state withholding. Results can show the exact entered amounts and 26-pay-period equivalents as a reconciliation reference. These detail lines do not change projected taxes, deductions, premiums, or net cash flow; blank lines stay blank, and withholding is not the same thing as annual tax liability.
What it does
This optional block records recognizable deduction lines from Person A's current LES. Results can show the exact entries beside simple 26-pay-period equivalents as a reference.
Best use
Use it to reconcile the current statement and recognize which lines may change at retirement. Blank fields stay blank rather than being filled with modeled amounts.
Important limit
These detail lines are reference only. They do not change projected taxes, premiums, TSP savings, FERS contributions, or net cash flow. Federal and state withholding are not annual tax liability. The separate biweekly net-pay field is the only LES amount used as a current-paycheck anchor in labeled working comparisons.
TSP
Balances, pre-retirement contributions, drawdown choices, and Roth conversion settings.
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Traditional TSP balance Your current Traditional TSP account balance. This is the pre-tax portion — contributions came out of your paycheck before taxes, and withdrawals will be taxed as ordinary income. FERSCalc treats the entered amount as valued at the start of the current calendar year, projects each working year through retirement, then starts withdrawals from the accumulated retirement-date balance.
What it means
This is your current pre-tax TSP balance. Withdrawals from it are generally taxable as ordinary income in retirement.
What to enter
Use the current Traditional balance shown on the TSP site or your latest statement, including any agency contributions that sit in the Traditional bucket. FERSCalc values this at the start of the current calendar year, then projects contributions and returns through retirement.
Why it matters
Traditional dollars are the main lever for taxable retirement income, so the accumulated retirement-date balance strongly affects future taxes, guardrails, RMD exposure, and withdrawal amounts.
Roth TSP balance Your current Roth TSP balance, valued at the start of the current calendar year. Contributions were made after tax, so qualified withdrawals are tax-free. Optional — leave it at zero if you have no Roth balance. If you have both Traditional and Roth, the withdrawal source setting determines which is drawn first after the pre-retirement timeline is projected.
What it means
This is the after-tax TSP bucket. Qualified withdrawals are tax-free, which makes Roth useful for income flexibility later.
Good default
Leave it at zero if you do not have Roth TSP. Agency matching still belongs in Traditional unless your agency has explicitly elected otherwise.
Why it matters
Having both Traditional and Roth balances unlocks withdrawal-source decisions and makes threshold-aware drawdowns possible.
First Roth contribution year The calendar year you made your first designated Roth TSP contribution. The IRS requires five tax years plus age 59½, total and permanent disability, or a payment after the participant's death for Roth earnings to be tax-free. The calculator uses a disability date only when you explicitly attest to that exception; it does not verify the underlying eligibility. This is the TSP plan's own five-year clock — a Roth IRA has a separate clock the calculator does not model, so do not enter a Roth IRA date here. If you leave this blank, designated Roth qualification cannot be verified. FERSCalc conservatively treats the entire Roth withdrawal as taxable because historical contribution basis is not collected, flags the affected years, and does not assume the distribution is qualified. Enter your actual first Roth TSP contribution year to get qualified (tax-free) treatment once you meet the five-year and age rules.
What it drives
For a known year, this helps FERSCalc apply the Roth five-tax-year rule together with age 59½, a user-attested total-and-permanent-disability date, or payment after death before treating Roth earnings as tax-free. The calculator does not verify disability eligibility.
When to use it
Enter the actual first designated Roth TSP contribution year whenever you know it. If you leave it blank, the qualification clock cannot be verified, so FERSCalc conservatively treats Roth earnings as taxable and flags affected years rather than assuming the account is qualified.
Why it matters
Without the five-tax-year and modeled age/death condition, Roth earnings can be taxable. FERSCalc tracks only basis created by modeled in-plan conversions for eligible balance withdrawals; it does not collect historical contribution basis. A nonqualified Roth-annuity payment is therefore conservatively treated as fully taxable.
Employee contribution rate Your TSP contribution as a percentage of basic pay. This is the employee deduction that comes out of your paycheck while you're still working, capped by the annual TSP elective-deferral and catch-up limits. FERSCalc separately adds the standard federal agency automatic/matching contribution to the Traditional TSP balance for federal employees, so paycheck impact and balance growth are modeled distinctly.
What it means
This is the employee percentage deducted from pay while you are still working. It affects both working take-home and pre-retirement balance growth.
Agency match
FERSCalc separately adds the standard federal automatic and matching contribution to the Traditional balance for federal employees, but never subtracts that employer share from your paycheck.
Why it matters
Contributing below 5% leaves match on the table. Contributing above 5% still grows the account, but not through additional agency matching.
Withdrawal strategy How you'll draw down TSP in retirement. If you enter a household spending plan, it SUPERSEDES the amount chosen here: the projection solves each year's draw to fund your spending target where the balance allows, then reports every year as funded or short; the strategy's own amount is not used. Your withdrawal-source ordering still applies. Without a plan, the strategy below decides the amount. Need-based uses either a nominal or today-dollar monthly target; the 4% rule and variable percentage draw proportionally from your balance. Floor/ceiling uses percentage change guardrails, not dollar floors. A statutory Traditional RMD remains a full annual floor in a midyear retirement row; FERSCalc prorates only planned balance spending above that floor. The Person A TSP-style annuity estimate uses entered premium and payout assumptions, not a TSP or insurer quote. It supports level or fixed 2% increasing payments, no/50%/100% survivor benefit, and no/ten-year-certain feature; survivor and period-certain are alternatives under 5 CFR 1650.14(g)(4), (i), and (j)(2). A joint-life choice requires an enabled, modeled Person B who is alive at purchase, but FERSCalc does not verify the relationship or age eligibility for a 100% survivor benefit under §1650.14(i)(3). Ten-year-certain payments after death are shown only to a living Person B as a household-only beneficiary approximation; beneficiary designations and non-household recipients are not modeled. If a purchase uses both Traditional and Roth balances, the TSP requires separate contracts and each nonzero contract must meet the $3,500 minimum under 5 CFR 1650.14(b)–(c). For a known first Roth contribution year, Roth-funded payments use the same five-tax-year plus age-59½, user-attested total-and-permanent-disability, or death qualification treatment as other Roth TSP distributions; qualification is assessed on each payment's monthly date, and disability eligibility is not verified. FERSCalc tracks basis created by modeled in-plan conversions only for eligible Roth balance withdrawals and does not collect historical Roth contribution basis. Because the annuity is purchased at retirement before modeled post-retirement conversions, a nonqualified Roth-funded payment is conservatively treated as fully taxable; a qualified payment is tax-free in the model. The model rejects a purchase on or after the owner’s modeled death date and represents the vendor’s approximately-30-day first payment as beginning in the following month; cash-refund and other vendor features are not modeled.
What it drives
This determines the annual withdrawal pattern once retirement starts, and is one of the biggest levers for income shape and balance durability — unless you enter a household spending plan, which supersedes the withdrawal AMOUNT and solves each year’s draw to fund your target where the balance allows, reporting any year it cannot. The withdrawal-source ordering you pick still applies either way.
How to choose
Choose based on whether you want fixed income, variable income, guardrails, or an annuity-style payout. Each option produces a different tradeoff.
Options at a glance
Need-based monthly target
Uses a monthly target you label as either nominal dollars or today’s dollars. Today-dollar targets are inflation-adjusted once per year; nominal targets are not.
4% rule
Starts at 4% of the year-one balance, then inflation-adjusts the dollar amount each year. Stable income, anchored to the opening balance.
Variable percentage
Withdraws a fixed percent of the current balance each year. Income moves with portfolio performance and remaining balance.
Floor / ceiling
Uses a percentage of the current balance, then limits the year-over-year decrease and increase around the prior inflation-adjusted withdrawal. Its guardrails are percentages, not dollar floors or ceilings.
Illustrative annuity estimate
Person A can model a TSP-style annuity only with entered premium, payout, and retirement-date purchase terms. The modeled options are level or fixed 2% increasing payments, no/50%/100% survivor benefit, and no/ten-year-certain feature; survivor and period-certain cannot be combined under 5 CFR 1650.14(g)(4), (i), and (j)(2). A joint-life election needs an enabled Person B modeled as alive at purchase, but FERSCalc does not verify the relationship or age eligibility for a 100% survivor benefit under §1650.14(i)(3). Ten-year-certain payments after death are a household-only beneficiary approximation shown only to a living Person B, not a beneficiary-designation model. If the purchase uses both Traditional and Roth balances, it produces separate contracts, and each nonzero contract must be at least $3,500 under 5 CFR 1650.14(b)–(c). The vendor’s approximately-30-day first payment is represented as beginning in the following month. Roth-funded payments are checked at their monthly payment date; qualified payments are tax-free in the model, while nonqualified payments are conservatively fully taxable because historical Roth contribution basis is not collected. Cash refund and other vendor options are not modeled, and FERSCalc does not provide an obtainable TSP or insurer quote.
First RMD payment timing Choose whether to take the first modeled Traditional TSP RMD in its obligation year or defer it until the following April. The projection uses the prior December 31 Traditional balance and the IRS Uniform Lifetime Table divisor, and records the required amount, actual amount paid, and any modeled shortfall in the distribution audit. Deferral can put two taxable RMDs in the following calendar year. It does not model a sole beneficiary spouse more than 10 years younger (Table II), inherited-account RMD rules, or the excise tax for an RMD shortfall.
What it controls
Choose whether to take the first modeled Traditional TSP required minimum distribution in its obligation year or defer it until the following April.
How the estimate works
The model starts at the later of the applicable RMD-age year and the modeled separation year. It divides the prior December 31 Traditional balance by the applicable IRS Uniform Lifetime Table divisor, then shows the obligation, payment date, actual modeled amount paid, and any modeled shortfall in the TSP distribution audit.
Important limit
Deferring can put two taxable RMDs in the following calendar year. The model does not apply the sole-beneficiary-spouse-more-than-10-years-younger Table II, inherited-account RMD rules, or an RMD-shortfall excise tax.
Early-distribution exception The projection separately adds the 10% federal additional tax to eligible taxable Traditional TSP cash distributions before age 59½. It derives the regular separation-after-55 rule from dates. SEPP, total-and-permanent-disability, and qualified-public-safety selections are user attestations: the calculator does not verify a SEPP payment schedule or recapture risk, disability eligibility, or plan-service facts. An attested disability date also supports the model's Roth qualification test. Roth in-plan-rollover recapture, inherited-balance provenance after a modeled spousal merge, generic nonfederal accounts, and other statutory exceptions are not modeled.
What it controls
The model separately calculates the 10% federal additional tax on eligible taxable Traditional TSP cash distributions before age 59½. It derives the normal separation-after-55 rule from dates rather than adding it to ordinary income tax.
What you attest
A SEPP, total-and-permanent-disability, or qualified-public-safety selection is an attestation. FERSCalc does not verify the SEPP payment method, modification/recapture risk, disability eligibility, or 25-year TSP-plan-service fact. An attested disability date also informs Roth qualification.
Important limit
Roth in-plan-rollover recapture, inherited-balance provenance after a modeled spousal merge, generic nonfederal retirement accounts, and other statutory exceptions are not calculated. Treat an incomplete additional-tax audit as a prompt to confirm the real distribution with a qualified tax adviser or plan administrator.
Annual withdrawal rate Only used with the variable percentage strategy. This is the percent of the current TSP balance withdrawn each year, so a 5% setting withdraws 5% of whatever balance remains at that point in time. Higher values increase near-term income but reduce long-term balance durability.
When it appears
This field is only used for the Variable percentage strategy.
How it works
A 5% setting means 5% of the current remaining balance is withdrawn that year, not 5% of the original retirement balance.
Why it matters
Higher rates lift near-term income but make the balance decline faster when returns are modest or negative.
Withdrawal source Which account to draw from first — Traditional (taxable) or Roth (tax-free). Traditional first maximizes tax-deferred growth in your Roth account. Roth first preserves Traditional for required minimum distributions. Threshold-aware mode uses a year-by-year guardrail heuristic: it draws Traditional up to a federal bracket or IRMAA ceiling, then switches to Roth for the rest.
When it matters
This only matters when you have both Traditional and Roth TSP balances available to draw from.
What it drives
It changes the split between taxable and tax-free withdrawals year by year, which can materially affect taxes, IRMAA, and ending balances.
Options at a glance
Traditional first
Uses taxable dollars first and leaves Roth in place longer for tax-free compounding.
Roth first
Uses tax-free dollars first to preserve Traditional for later, which can help when you want lower taxable income early in retirement.
Threshold-aware
Uses Traditional up to a bracket or IRMAA ceiling, then switches to Roth. This is a year-by-year guardrail heuristic, not a full optimizer.
Guardrail rule Only active with threshold-aware withdrawal source. Sets the ceiling that triggers the switch from Traditional to Roth. Federal bracket ceiling stops Traditional draws at the next bracket boundary. IRMAA ceiling aims to avoid higher Medicare premium tiers. Lower of both uses whichever threshold is hit first each year.
When it matters
This only applies when the withdrawal source is Threshold-aware.
What it drives
It defines which published threshold causes the model to stop using Traditional withdrawals and switch to Roth for the rest of the year.
Options at a glance
Federal bracket ceiling
Stops Traditional draws at the next federal bracket boundary so more of the draw stays within the current marginal rate.
IRMAA ceiling
Uses the next Medicare premium threshold as the ceiling to reduce the chance of triggering a higher IRMAA tier.
Lower of both
Uses whichever ceiling is hit first in a given year for the most conservative threshold-protection approach.
Roth conversion strategy Choose how Traditional-to-Roth TSP in-plan conversions should be modeled after retirement. Strategies can use a fixed amount, fill a target tax bracket, stay under an IRMAA tier, convert a percentage each year, or aim to reach zero Traditional balance by the first RMD year. Converted dollars stay inside TSP, increase taxable income for that year, and are not spendable cash.
What it does
This models in-plan conversions from Traditional TSP to Roth TSP after retirement using one of several strategies: fixed amount, fill a target tax bracket, stay under an IRMAA tier, convert a percentage each year, or target zero by the first RMD year.
Tax treatment
Converted dollars count as taxable income in the conversion year and affect federal tax, state tax, MAGI, and IRMAA logic. The model tracks conversion-created basis for eligible future Roth balance withdrawals; a retirement-date illustrative-annuity purchase happens before this modeled conversion window.
Important limit
The conversion is not spendable cash. FERSCalc treats it as a deliberate tax-planning move, not an extra withdrawal.
Annual conversion amount The dollar amount to convert from Traditional TSP to Roth TSP each year in the selected window. FERSCalc caps the conversion at the remaining Traditional balance after any required minimum distribution for that year.
What it means
This is the yearly dollar amount you want moved from Traditional TSP to Roth TSP during active conversion years.
How it is capped
FERSCalc limits the conversion to what remains in Traditional after any required minimum distribution for that year.
Why it matters
This amount directly controls how much taxable income you intentionally add during the conversion window.
Conversion window The first and last calendar years when the selected in-plan Roth conversion strategy should run. Use this to model a controlled multi-year conversion plan rather than assuming conversions continue forever.
What it means
This defines the first and last calendar years when the selected Roth conversion strategy should run.
Why timing matters
The timing affects not only current-year taxes, but also later IRMAA exposure, RMD pressure, and the mix of taxable versus tax-free dollars later on.
Good use
Use it to model a deliberate multi-year conversion plan such as converting through the early retirement window before larger RMDs begin.
Annual conversion percentage Only used with the Percentage strategy. FERSCalc converts this share of the remaining Traditional balance each active year, subject to required minimum distributions and the configured year window.
When it applies
This is only used with the Percentage strategy.
What it means
Each active year, FERSCalc converts this share of the remaining Traditional balance after any required minimum distribution.
Why it matters
It creates a declining conversion pattern that naturally shrinks as the Traditional balance falls.
Target bracket Only used with Fill Tax Bracket. FERSCalc estimates the federal taxable-income room remaining in the selected marginal bracket for that calendar year, then converts up to that ceiling.
When it applies
This is only used with Fill Tax Bracket.
What it means
FERSCalc estimates the taxable-income room left inside the selected federal bracket for that calendar year and converts up to that ceiling. Published IRS rule sets are used through 2026; later brackets are projections, not enacted future law.
Tradeoff
This can reduce future RMD pressure, but it intentionally adds taxable income now.
Target IRMAA tier Only used with Stay Under IRMAA. FERSCalc estimates MAGI for the selected year and converts only up to the chosen Medicare IRMAA tier ceiling.
When it applies
This is only used with Stay Under IRMAA.
What it means
FERSCalc estimates MAGI and converts only up to the selected Medicare IRMAA threshold.
Tradeoff
This is more conservative than a pure tax-bracket strategy because it also protects against higher future Medicare Part B premiums.
Monthly withdrawal target For the need-based strategy, choose whether this monthly amount is nominal or today’s dollars. Today-dollar targets inflate once per projection year; nominal targets do not. Floor/ceiling does not use this dollar field — it uses an annual balance percentage and maximum percentage changes around the prior year's inflation-adjusted withdrawal.
When it appears
This field is used only for the need-based strategy.
How it works
Choose whether the amount is nominal dollars or today’s dollars. Today-dollar targets receive one annual inflation adjustment; nominal targets do not. Floor/ceiling instead uses percentage inputs.
Why it matters
It sets the income expectation the TSP must support and materially changes both withdrawal size and balance durability over time.
FEHB
Health premium inputs that show how retiree coverage affects after-premium cash flow.
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Include FEHB premium Whether to include your Federal Employee Health Benefits premium in projected retirement cash flow. FEHB continues into retirement for retirees who were continuously enrolled for at least 5 years before retiring, and premiums are generally deducted from the annuity payment. Enable this to include the employee premium as an annual household deduction. The retirement timeline continues to show gross benefit timing, not an exact OPM net deposit.
What it does
Adds the retiree FEHB premium as an ongoing deduction so results show after-premium pension cash flow instead of gross pension only.
Eligibility reminder
Continuing FEHB into retirement generally requires five years of continuous enrollment before retirement, or coverage for all federal service if shorter.
Why it matters
FEHB is one of the most valuable federal retirement benefits, but it is also one of the clearest reasons gross pension and deposited pension are not the same.
Retirement Elections
One-time retirement choices and service-credit adjustments that can affect survivor income and pension size.
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Total FERS cost at annuity start Your total cost in the FERS plan at the annuity starting date, from the OPM statement approving your annuity, a CSA/CSF 1099-R, or a retirement estimate that explicitly projects that total. FERSCalc treats the entry as the final commencement-date cost for the IRS Simplified Method and does not add future modeled payroll contributions. Do not enter a current-to-date contribution balance unless your source has already projected it through annuity commencement. If no reliable total is available, leave the field blank; the projection then models no tax-free cost recovery and may overstate taxable pension income.
What it drives
This is your total cost in the FERS plan at the annuity starting date. When entered, FERSCalc uses the IRS Simplified Method to estimate the tax-free part of each FERS annuity payment until that cost is recovered.
Where to find it
Use the total cost shown on the OPM statement approving your annuity or a CSA/CSF 1099-R. Before retirement, use only a retirement estimate that explicitly projects total contributions through annuity commencement. Confirm the amount with OPM or a tax professional if your records are unclear.
Important input contract
Treat this as the final total at annuity start, not a current-to-date balance. FERSCalc does not add future modeled payroll contributions to it. Adding them would double-count an OPM total, while payroll deductions alone cannot reconstruct deposits, redeposits, and other cost adjustments. If you leave it blank, the projection models no tax-free cost recovery and may overstate taxable pension income.
Survivor benefit election An election you make at retirement that determines what income your surviving spouse receives if you die first. Full (50%) costs 10% of your pension and pays your survivor 50% of your unreduced pension for life. Partial (25%) costs 5% and pays 25%. None gives you the highest pension now but leaves no survivor income. This election is permanent and irrevocable after retirement.
What it drives
This election determines how much pension income a surviving spouse keeps if the retiree dies first and how much the retiree’s own pension is reduced to fund that protection.
Why to slow down
This is usually irrevocable after retirement processing. It also interacts with whether a surviving spouse can remain on FEHB.
Options at a glance
Full survivor benefit (50%)
Reduces the retiree pension by 10% and leaves the spouse with 50% of the unreduced annuity for life.
Partial survivor benefit (25%)
Reduces the retiree pension by 5% and leaves the spouse with 25% of the unreduced annuity.
No survivor benefit
Leaves the retiree pension unreduced but provides no spouse pension after death and generally requires spousal consent.
FERS Supplement (SRS) The Special Retirement Supplement is an additional monthly payment from your retirement date until age 62. It approximates the Social Security benefit you earned during your FERS civilian career, so its service factor uses FERS civilian service only — military time you bought back counts toward your pension but not the supplement. If you retire before 62 with an immediate unreduced pension, you may qualify. FERSCalc treats it as ordinary retirement income for its federal and state planning calculations, not as Social Security. Federal law also applies an earnings test to post-retirement wages and self-employment income; FERSCalc accepts employee wages only, so evaluate self-employment separately. If you retired under special provisions (law enforcement, firefighter, air traffic control — “6C”), the earnings test does not apply until you reach your minimum retirement age.
What it means
This is the bridge payment that can help eligible retirees cover the gap between retirement and age 62, when Social Security first becomes available.
Who gets it
It generally applies to immediate unreduced retirements before age 62, not to MRA+10 or deferred cases.
Why it matters
It can materially improve early-retirement cash flow, but it stops at 62 and does not receive COLA adjustments the way the pension does. Federal law also applies an earnings test to post-retirement wages and self-employment income.
Annual earned income after retirement Post-retirement employee wages that count against the FERS supplement earnings test before age 62. Do not include your FERS pension, TSP withdrawals, Social Security, investment income, other retirement income, or net self-employment income. FERSCalc adds this as taxable household wage income, cash flow, MAGI, and FICA wages, and also uses it for the supplement earnings test. Because OPM applies the earnings test to the prior year's earnings, a given year's wages reduce next year's supplement — so the first supplement year is never reduced. Self-employment tax is not modeled.
What it means
This is wage or self-employment income after retirement that counts against the FERS supplement earnings test before age 62.
What to exclude
Do not include FERS pension, TSP withdrawals, Social Security, investment income, or other retirement income. Those are not earnings for the SRS test.
Scope note
FERSCalc uses this value only to reduce the supplement. It does not add the amount as taxable wage income elsewhere in the projection.
Sick leave balance Unused sick leave can add service only to the annuity computation after eligibility and special-category tiers are determined. FERSCalc converts hours using OPM's 2,087-hour chart; it cannot create vesting, a 20-year 6C threshold, or any deferred-annuity credit. Use the balance on your LES and enter hours, not days.
What it does
Unused sick leave converts into additional computation credit after FERS eligibility and special-category tiers are established. It cannot create vesting, immediate eligibility, or a twentieth 6C year.
Where to find it
Use the sick leave hours shown on your LES. Enter hours, not days.
Why it matters
FERSCalc uses OPM’s 2,087-hour conversion chart and adds the resulting days to the service record before dropping a remaining fractional month. Deferred annuities do not receive sick-leave credit.
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