How California Divides Property

California is one of nine community property states, and it is one of the strictest about following the rule. The starting point is this: everything earned or acquired during the marriage belongs to both spouses equally, and at divorce it is divided fifty-fifty. Not "what's fair given who earned more." Not "what the judge thinks makes sense." Fifty-fifty, by default, with the burden on the spouse who wants to argue otherwise.

The harder question is always: is this thing community or separate?

§ 01The two categories

Community property includes anything either of you earned or bought with earnings during the marriage, up to the date of separation. Paychecks. The portion of a 401(k) contributed during the marriage. The equity that built up in your house while you were married. A car bought with marital money. A business interest started during the marriage. Debts taken on during the marriage are also community, even ones in only one spouse's name.

Separate property is anything one spouse owned before the marriage, plus anything received during the marriage as a gift to one spouse alone or as inheritance. Income earned after the date of separation is also separate property — which is why that date matters so much.

§ 02Commingling, and why it ruins everything

The categories are clean. Real life is not. The most common problem is that separate property and community property get mixed together — "commingled" — and the law has to figure out what's still separate and what has effectively become community.

The classic example: one spouse comes into the marriage with $50,000 in a savings account. They keep the account in their own name. Throughout the marriage, paychecks are deposited into it, withdrawals are made for groceries and vacations, and after fifteen years there's $200,000 in the account. Is any of that still separate?

The answer depends on whether the spouse can trace the separate funds. There are two accepted accounting methods, and both are tedious: showing every deposit and withdrawal, and demonstrating that the separate funds are still in there. If you cannot trace them — if the records are gone, if the deposits and withdrawals are too tangled — the entire account is presumed to be community.

This is one of the strongest arguments for keeping pre-marriage money in a separate account that never receives marital deposits. Once the streams mix, untangling them is expensive and often impossible.

§ 03The house question

For most California couples, the family home is the largest asset and the most legally complicated. The basic scenarios:

You bought the house together during the marriage

Cleanest case. The house is community property. At divorce, it is divided fifty-fifty — meaning the equity is split, after the mortgage and any selling costs. Either spouse can buy the other out, you can sell and split the proceeds, or in some cases (especially with children) one spouse can stay in the house under a deferred sale arrangement.

One spouse owned the house before the marriage

The house starts as separate property. But if marital income paid the mortgage during the marriage, the community has acquired an interest in the house. The Moore-Marsden formula — named for two California cases — calculates exactly what share the community is entitled to, based on the percentage of the principal that was paid down with marital money and the appreciation that share earned.

Worked examples get long, but the principle is straightforward: the longer you were married, and the more of the mortgage you paid down together, the larger the community's slice of an originally-separate house.

One spouse owned the house, and added the other to the title

This is called transmutation, and California requires it to be done in writing with explicit language stating that the character of the property is being changed. Just adding a name to a deed during the marriage often doesn't do it on its own — but it can, depending on the wording, and these cases are heavily fact-specific.

§ 04Retirement accounts

Retirement accounts are usually a mix. The portion that built up before the marriage is separate. The portion that built up during the marriage is community — including not just the contributions, but also the gains attributable to those contributions.

Dividing them requires a special court order called a Qualified Domestic Relations Order (QDRO) for ERISA-governed plans like 401(k)s and pensions. IRAs don't need a QDRO but do need to be transferred under a specific divorce-related provision to avoid being treated as a taxable withdrawal. This is one of the areas where DIY divorce most often goes wrong — the wrong document type, or no document at all, and a person ends up paying taxes and penalties on a transfer that should have been tax-free.

§ 05Businesses

If one spouse founded or owned a business before the marriage, and the business grew during the marriage, the community is generally entitled to a share of that growth. California uses two valuation methods — Pereira and Van Camp, again named for old cases — depending on whether the growth came primarily from the spouse's labor or primarily from market forces.

Business valuation in divorce almost always requires a forensic accountant. It is one of the most expensive parts of any case where it applies, and one of the most worth getting right.

§ 06Debts

Debts are property too, just running in the other direction. Debt taken on during the marriage is community, even if only one spouse signed for it — except in narrow cases (typically debts for one spouse's separate purposes that didn't benefit the community).

Credit card debt, mortgages, student loans taken on during the marriage, business debts — all are presumed community. At divorce, they are divided along with assets, and the resolution typically pairs each debt with the asset it relates to: the spouse who keeps the car keeps the car loan, the spouse who keeps the house keeps the mortgage.

§ 07What's actually fought about

In real cases, property fights cluster around a few recurring questions:

• The date of separation — because earnings after that date are separate.
• Whether commingled separate property can still be traced — because if it can't, it becomes community.
• The community's share of a separate-property house — Moore-Marsden math, with both sides hiring experts.
• Business valuation — what the business is worth and how much of its growth is community.
• Allegations of breach of fiduciary duty — wasting community assets, hiding income, undisclosed accounts, money spent on an affair.

Each of these is its own world. If your divorce involves any of them seriously, the cost of getting it wrong is much higher than the cost of paying a careful family law attorney to walk through it with you.