How much of his 401(k) or pension counts as mine?
Key numbers
- Nine states are community property states, where the starting point is a 50/50 split: Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington and Wisconsin (source: IRS Publication 555). The other 41 states and DC divide marital property in a way the judge considers fair, which is not always equal.
- Splitting a 401(k) or a pension needs a separate court order called a QDRO, and most plans will not pay a former spouse anything until the plan administrator has one on file (source: IRS).
- An IRA needs no QDRO: a transfer of an interest in an IRA to a former spouse under a divorce decree is not treated as a taxable transfer (source: IRS Publication 504).
- Money paid to a former spouse from a qualified plan under a QDRO escapes the 10% extra tax on early withdrawals that normally applies before age 59 and a half (source: IRS Topic 558).
Most women are told the retirement accounts will be “split” and never told what that means in dollars. It is rarely the whole balance, it is rarely a clean half, and the answer depends on two things: how much of the account was built during the marriage, and which state is deciding. Put your numbers in and see the shape of it.
Do one account at a time. If there are three accounts, run this three times and write down each answer.
Only part of the account is on the table
Retirement money splits into two piles. What he saved before the wedding is usually his alone. What went in during the marriage is usually marital property, and marital property is what gets divided. So the first job is working out how big that second pile is.
For a 401(k), a 403(b) or an IRA, the everyday method is subtraction: the balance today minus roughly what was in it on your wedding day. If the account was opened after you married, the whole thing is marital and the subtraction is from zero.
A pension works differently, because there is no balance to subtract. A pension is a promise of a monthly check for life, and it was earned year by year. So the usual method is a fraction: the years he was in the plan while you were married, divided by the total years he was in the plan. That fraction of the pension is marital. Lawyers call it the time rule or the coverture fraction. It is just a fraction.
Then your state decides how that pile is cut
Nine states are community property states: Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington and Wisconsin (IRS Publication 555). There, money earned and saved during a marriage is treated as owned half and half, so the starting point is a 50/50 split of the marital portion. Everywhere else is an equitable distribution state. There, the judge divides the marital portion in a way that is fair, which is not always equal.
That word “fair” is doing real work. Length of the marriage, health, who can earn what going forward, who gave up a career, and what else is being traded all move the line. Divisions cluster in a 40% to 60% band, which is why this tool gives you a range in those states rather than pretending to know one number. Judges and states differ, and anyone who gives you a single guaranteed figure is guessing.
Three examples, run through the calculator above
Every figure below is produced by the same code the tool runs, so nothing here is a made-up number.
Maya, 58, Ohio: household income about $60,000
One 401(k) with $140,000 in it. About $20,000 was already there when they married 24 years ago. The marital portion is $120,000. Ohio is an equitable distribution state, so Maya’s indicative share lands between $48,000 and $72,000. That gap of $24,000 is not noise. It is the thing worth negotiating over.
Dana, 55, Texas: household income about $110,000
His 401(k) holds $480,000 and it was opened two years after the wedding, so nothing was in it before. The whole $480,000 is marital. Texas is a community property state, so the starting point is a straight half: $240,000. Dana still needs a QDRO before the plan will move a cent of it.
Priya, 52, New York: household income about $200,000
No big 401(k), but he has a pension the plan values at $900,000. He has been in the plan 28 years, and 18 of those years were inside the marriage. The time rule makes 18 of 28 marital, which is $578,571. New York is an equitable distribution state, so Priya’s indicative share runs from $231,429 to $347,143. Priya nearly accepted a settlement that treated the pension as his, because it was never on the list of assets.
The QDRO, and why it is not optional
Winning a share of a 401(k) or a pension in the divorce is only half the job. The plan is a separate organisation and it does not take instructions from a divorce decree. It needs its own order, a Qualified Domestic Relations Order. The IRS describes a QDRO as a judgment, decree or order for a retirement plan to pay child support, alimony or marital property rights to a spouse, former spouse, child or other dependent of a participant (IRS). The IRS is blunt about what happens without one: most plans require an ex-spouse to file a QDRO with the plan administrator before the plan can pay any portion of the benefits (IRS).
QDROs apply to employer retirement plans, the kind covered by the federal law called ERISA (US Department of Labor). An IRA is not one of those. An IRA is divided in the decree and moved by direct transfer, and the IRS says that transfer is not treated as a taxable transfer (Publication 504).
One more piece of the QDRO worth knowing: normally, pulling money out of a retirement plan before age 59 and a half adds a 10% extra tax on top of ordinary income tax. Distributions made to a former spouse as an alternate payee under a QDRO are on the IRS list of exceptions to that extra tax (Topic 558). That exception applies to qualified plans, not to IRAs. It matters if you will genuinely need some of this money before 60, and it is a decision to make with a tax professional rather than on a website.
What the estimate cannot see
A few things move the real number and are not in any calculator. Growth on the premarital pile is treated differently state to state. Some plans have early retirement subsidies or survivor benefits that are worth real money and get missed. Loans against a 401(k) reduce what is there. A pension the plan values at one figure may be worth a different figure to you, depending on your age and health. And the retirement accounts are almost never traded on their own: they get weighed against the house, which is the next tool.
Frequently asked questions
What is a QDRO, in plain English?
It is a separate court order that tells a retirement plan to pay part of one person’s account to a former spouse. The IRS describes it as a judgment, decree or order for a retirement plan to pay marital property rights to a spouse, former spouse, child or other dependent. Most plans will not release anything until the plan administrator has one on file.
Does an IRA need a QDRO too?
No. An IRA is not an employer plan, so it is divided through the divorce decree itself and moved as a direct transfer between retirement accounts. IRS Publication 504 says a transfer of an interest in an IRA to a spouse or former spouse under a divorce decree is not treated as a taxable transfer.
Do I owe tax when the 401(k) is split?
Moving your share into a retirement account in your own name is not a taxable event. Tax is owed when money actually comes out and is spent. Taking cash out instead of transferring it means income tax on the whole amount that year.
Is the account split exactly in half?
Only the marital portion is divided, not always the whole balance, and only nine states start from a 50/50 rule. Everywhere else the judge divides marital property in a way that is fair, which is not always equal, so the honest answer is a range.
What if the account grew a lot after the wedding?
Growth on the money that was already there before the marriage is treated differently from state to state. Some states keep it separate, some treat part of it as marital. This tool shows the simple subtraction, and the growth question is worth raising with whoever is advising you.
He says the pension is his because he earned it. Is that right?
A pension earned during a marriage is normally treated as marital property in every state, whatever the paycheck said. The usual method is a time-rule fraction: the years of plan participation that happened inside the marriage, divided by the total years of participation.
Sources: IRS, Retirement topics: QDRO · IRS, Retirement topics: divorce · IRS Topic 558, additional tax on early distributions · IRS Publication 504, divorced or separated individuals · US Department of Labor, QDROs: an overview · IRS Publication 555, community property. All fetched and checked September 2026. Nothing here is legal or tax advice.
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