FERS & CSRS annuity in divorce: court-ordered apportionment (COAP)
Your federal pension is often the largest asset in a federal divorce — and it’s divided by a document most attorneys rarely touch. Not a QDRO, but a COAP, drafted in OPM’s exact language, that splits the annuity by a marital fraction, decides whether your former spouse keeps a survivor benefit after you die, and — since a quiet 2016 rule change — can carve up your supplement too. Get the wording wrong and OPM simply won’t process it. This guide explains how the division actually works in 2026, with an apportionment calculator so you can see the numbers before the lawyers do.
1. COAP, not QDRO
Start with the single most expensive misunderstanding in federal divorce: a QDRO does not work on a federal pension. Qualified Domestic Relations Orders come from ERISA, and CSRS and FERS are governmental plans exempt from ERISA. OPM will not honor a standard QDRO. What it honors is a Court Order Acceptable for Processing (COAP) — an order written in the specific language laid out in OPM’s Handbook for Attorneys on Court-Ordered Retirement, Health Benefits, and Life Insurance.
OPM does nothing unless the order is specific and clear. It must identify the benefit (CSRS/FERS retirement), and state the former spouse’s share as a fixed dollar amount, a percentage, a fraction, or a formula whose value OPM can compute from its own records. A vague “half the pension” without the right structure gets rejected. This is not boilerplate — have it drafted by someone who knows the Handbook.
2. When OPM actually acts
Filing the COAP doesn’t start any money moving. OPM will not divide the annuity until you have separated from federal service, become eligible for an annuity, and actually applied for it. A court order can sit on file for years while you keep working; nothing is paid until your annuity begins.
Once you retire and OPM has a certified copy of an acceptable order, it pays the former spouse’s share directly to them and reduces your monthly payment by that amount. Only payments made after OPM receives the order are divided — another reason to file the certified copy promptly. And critically: the former spouse’s right to a share of your living annuity ends when you die. What happens after death is a separate question (section 6).
3. The prorata marital fraction
The most common division method is the prorata share, built on a marital fraction. The former spouse gets a percentage — usually 50% — of the slice of your career that overlapped the marriage:
So a 50% award against a marriage covering 200 of 360 total service months yields 50% × (200/360) = about 27.8% of the annuity. One non-obvious consequence: the longer you work after the divorce, the smaller the marital fraction becomes — though your high-3 may climb with promotions, partly offsetting it in dollar terms. The calculator below makes this trade-off visible.
4. Gross, net, or self-only
A percentage of what, exactly? OPM recognizes three annuity bases, and the COAP should name one:
| Base | What it means |
|---|---|
| Gross annuity | The payment after any survivor reduction but before insurance, taxes, and other deductions. OPM’s default if the order is silent. |
| Net annuity | Gross minus health/life premiums, withholding, and other court-ordered amounts. Also called the “disposable” annuity. |
| Self-only annuity | The annuity as if no survivor benefit were elected — a larger base than gross. |
If the parties want anything other than gross, the order must say so. The choice meaningfully changes the dollars, so it’s worth negotiating deliberately rather than defaulting.
5. Apportionment calculator
Enter the gross monthly annuity, total months of creditable service, the months of service that fell within the marriage, and the award percentage. The calculator returns the marital fraction, the former spouse’s monthly share, and what’s left for you.
COAP apportionment calculator
Prorata marital-fraction method, applied to the gross annuity. Estimate only — the COAP’s exact wording controls the real result.
6. The survivor annuity is separate
Here’s the trap that leaves former spouses with nothing. Dividing the living annuity and awarding a former-spouse survivor annuity are two distinct awards — and the court order must expressly grant each. Split the monthly pension while you’re both alive, stay silent on survivorship, and the former spouse receives nothing after your death.
Under FERS, the maximum former-spouse survivor annuity is 50% of your annuity, and electing a full survivor benefit reduces your own annuity by 10% (CSRS allows up to 55%, at a graduated cost). The former spouse generally must have been married to you at least nine months to qualify. And a survivor election or court-ordered survivor award can only be put in place or modified before you retire or die — miss that window and it can’t be fixed. A former-spouse survivor annuity also terminates if the former spouse remarries before 55 (when the marriage lasted under 30 years), which interacts with remarriage planning on both sides.
7. The supplement split (2016)
If you retire before 62 with the FERS annuity supplement, a 2016 policy change matters. For nearly 30 years, OPM divided the supplement only if the court order expressly named it. Since July 2016, OPM apportions the supplement in the same percentage as the gross FERS annuity award unless the order says otherwise.
If a COAP gives your former spouse 30% of your gross annuity and is silent on the supplement, OPM now also pays them 30% of the supplement. To keep the supplement undivided, the order must explicitly exclude it. Old orders written before 2016 were swept into this too, which caught many retirees by surprise.
8. COLA, taxes & the TSP
Three loose ends that change the real numbers:
- COLA pass-through. Unless the decree says otherwise, the former spouse’s share rises with each annual COLA just like yours.
- Taxes. The former spouse reports and pays tax on their apportioned share. Your 1099-R reflects the reduced amount, and OPM marks the taxable portion “Unknown,” so you’ll compute the tax-free piece yourself or with a preparer.
- The TSP is divided separately. Your TSP isn’t touched by the COAP — it’s split by a separate Retirement Benefits Court Order (RBCO) handled by the TSP, not OPM.
The federal-divorce framework parallels the military one in spirit; if you also have military service, compare it against USFSPA division rules, which work differently.
9. Frequently asked questions
What is a COAP and how is it different from a QDRO?
A COAP, or Court Order Acceptable for Processing, is the specific type of court order OPM uses to divide a FERS or CSRS annuity in divorce. It is not a QDRO. QDROs are creatures of ERISA, and federal civil service retirement is a governmental plan exempt from ERISA, so OPM will not honor a standard QDRO. The order must be drafted in the precise language OPM specifies in its Handbook for Attorneys, identify the benefit being divided, and state the former spouse's share as a dollar amount, percentage, fraction, or a formula OPM can compute from its own records. Vague orders are rejected, so the drafting matters enormously.
How is the former spouse’s share of a federal pension calculated?
The most common method is the prorata or marital-fraction formula. The former spouse receives a percentage, usually 50 percent, of a fraction whose numerator is the number of months of creditable service performed during the marriage and whose denominator is the total months of creditable service. So if 200 of 360 service months overlapped the marriage and the award is half the marital share, the former spouse receives 50 percent times 200/360, or about 27.8 percent of the annuity. OPM applies the percentage to the gross annuity unless the court order specifies the net or self-only annuity instead.
Does a divorce automatically give my ex a survivor annuity?
No. A share of the living annuity and a former-spouse survivor annuity are two separate awards, and the court order must expressly grant each one. Dividing the monthly pension while you are both alive does nothing for the former spouse after your death unless the order specifically awards a former-spouse survivor annuity using OPM's required language. Under FERS the maximum former-spouse survivor annuity is 50 percent of the annuity, and providing a full survivor benefit reduces your annuity by 10 percent. The former spouse generally must have been married to you at least nine months to qualify.
Is the FERS supplement divided in a divorce?
It can be, and the rule changed in 2016. Before then OPM only divided the FERS annuity supplement if the court order expressly mentioned it. Since July 2016, OPM apportions the supplement in the same percentage as the gross FERS annuity award unless the order says otherwise. So if a court order gives your former spouse 30 percent of your gross annuity and is silent on the supplement, OPM will also pay them 30 percent of your supplement. If you want to keep the supplement undivided, the order has to say so explicitly.
When does OPM start paying my former spouse?
OPM does not divide anything until you have separated from federal service, are eligible for an annuity, and have actually applied for it. A court order on file does not generate payments while you are still working. Once your annuity begins and OPM has a certified copy of an acceptable order, it pays the former spouse's share directly to them and reduces your payment accordingly. The former spouse's right to the share of your living annuity ends when you die, which is exactly why a separately awarded survivor annuity matters. The former spouse also pays income tax on their own share.
- OPM, Court-Ordered Retirement Benefits FAQ
- Congressional Research Service, Annuities for Former Spouses (RS22856)
- eCFR, 5 CFR Part 838 — Court Orders Affecting Retirement Benefits
- QDRO Helper, dividing FERS/CSRS benefits in divorce
- Government Executive, OPM apportioning the annuity supplement
- MyFederalRetirement, court orders and CSRS/FERS annuities