The Days OPM Drops From Your Pension — and Why Sick Leave Is the One You Can Still Change

Every annuity computation starts from a length of service stated in whole months, and OPM gets there by throwing days away. Add up your civilian service, your military service, and your unused sick leave, and whatever is left over once the total clears its last full month is simply discarded — not rounded, not carried into next year's computation, not paid out in any other form. Sick leave is the one piece of that total still open to you on your last day, because the chart that converts it always rounds in your favor. Whether that matters for your own balance depends entirely on where the days you already have land against a 30-day line.

The rule that throws days away

OPM's own instructions for computing length of service are direct about it: "Length of service for annuity computation purposes is based on whole months (30 days). To determine the total length of service for annuity computation purposes, add all creditable civilian and military service and the period represented by the unused sick leave; then eliminate any fractional part of a month."

The handbook's own worked example shows exactly what "eliminate" means. An employee has 30 years, 1 month, 16 days of civilian service and 2 years, 0 months, 10 days of military service. Their unused sick leave balance converts to 9 months, 1 day. Add the three together — 32 years, 10 months, 27 days — and the annuity is computed on 32 years and 10 months. The handbook's own note: "The 27 days are dropped."

Nothing is wrong with that employee's arithmetic. The days were real, they were creditable, and OPM discarded all 27 of them anyway, because the computation only recognizes whole months. The same caution appears in the same section for a different reason: "Accrued and unused sick and/or annual leave may not be used to meet the service requirements for eligibility to retire." Sick leave buys computation credit only — it was never going to move your retirement date, and this guide is not about that question. What it is about is what happens to the credit sick leave does buy, once it is added to everything else.

The one rule that works in your favor

Before those days can be dropped, OPM has to convert your sick leave hours into days in the first place, and that conversion is deliberately generous. The chart used to do it does not list every hour balance between 0 and 2,087 — there are gaps — and the handbook's instructions are explicit about which way to round when your balance falls in one: "If a figure on the chart does not correspond exactly to the total hours of unused sick leave an employee has to his or her credit at time of retirement, use the next highest number." A balance of 1,500 hours is not itself listed; 1,496 hours and 1,501 hours are the two nearest chart entries, and the rule says to use 1,501 — crediting the employee for one hour they had not actually banked.

That 2,087-hour figure is not specific to retirement; it is the standard federal work year defined at 5 U.S.C. § 5504(b)(1) to derive an hourly rate from an annual salary ("To derive an hourly rate, divide the annual rate by 2,087"). Retirement computations spread the same 2,087 hours across a 360-day service year of 30-day months, which works out to a little under 5.8 hours per calendar day. Because the chart always rounds a partial-day balance up rather than down, a single day of credit costs a flat 6 hours on the chart — more than the 5.8-hour figure the division alone would produce, and the Sick Leave Conversion Calculator reproduces that same chart rather than dividing.

Where the two rules meet

Rounding hours up and dropping leftover days pull in opposite directions, and which one dominates for a given balance depends on a number that has nothing to do with sick leave at all: the odd days already sitting in the rest of your creditable service, left over after the same 30-day-month arithmetic is applied to your civilian and military time. Running the handbook's own 1,571-hour sick leave balance — which converts to 9 months and 1 day, 271 days total — through the site's calculator against two different odd-day totals from the rest of a career shows the range. Against 4 odd days already on hand, the total needs 145 more sick leave hours before another month of credit is reached. Against 25 odd days already on hand, the same 1,571-hour balance is only 24 hours from the next month.

That is the whole mechanism in one comparison: the value of the next sick leave hour a federal employee accrues is not fixed. It depends on the remainder already carried by the rest of their career, a number the calculator works out for a given balance but that no employee is likely to know offhand without running it.

What this doesn't decide

None of this changes whether you are eligible to retire on a given date — OPM's caution above is unambiguous that sick leave cannot do that, and how eligibility and computation service diverge covers the full set of rules for that separate question. This guide is only about what happens to the credit sick leave does buy once your total length of service is rounded down to whole months for the computation itself.

Frequently asked questions

Does adding one more hour of sick leave always add value to my pension?

Not by a fixed amount. Because the chart spreads 2,087 hours across a 360-day year, roughly 5.8 hours of sick leave typically convert to the same day of credit — so an hour added inside that range changes nothing on its own. What decides whether a given hour crosses into a new month of credit is the total of your sick-leave days combined with the leftover days from the rest of your creditable service, not the hour in isolation.

What happens to the days that don't add up to a whole month?

They are dropped from the computation. OPM's own instructions eliminate any fractional part of a month once civilian service, military service, and converted sick leave are added together — the handbook's example drops 27 real, creditable days from a 32-year, 10-month, 27-day total, crediting only the whole months.

Does unused sick leave count toward my eligibility to retire?

No. OPM's handbook states it as a caution: accrued and unused sick leave may not be used to meet the service requirements for retirement eligibility, only the length of service the annuity is computed from. See eligibility vs. computation for how that distinction plays out across every kind of creditable service, not just sick leave.

Why does the chart round sick leave hours up instead of dividing evenly?

Because OPM built it as a lookup table rather than a formula, and its own instructions say to use the next highest listed figure whenever a balance falls between two chart entries. The practical effect is that partial-day balances are never shortchanged — a balance just above a chart entry is credited as if it had reached the next one.

This guide is informational only. It is not financial, tax, or legal advice, and FedAnnuity is not affiliated with OPM or the U.S. government. Retirement rules turn on the specific facts of a career, and only your agency and OPM can give you a binding figure.

Last reviewed: September 2026 · Against primary sources cited in the body.