Community Property vs. Common Law: What Your Spouse Already Owns

Community Property: The 50/50 Rule

In community property states, most assets acquired during the marriage are community property — owned equally by both spouses. This includes wages, salaries, bonuses, business income, investment returns on community assets, and real or personal property purchased with community funds. It does not matter which spouse earned the income or which spouse's name appears on the title. If it was acquired during the marriage with marital effort or marital funds, it belongs to both spouses equally.

Separate property — assets each spouse owned before the marriage, or received during the marriage by gift or inheritance — remains that spouse's individual property, as long as it is not commingled with community property. This distinction between community and separate property is the single most important classification in community property estate planning.

Common Law: Title Controls

In common law (also called separate property or equitable distribution) states, ownership follows title. If the husband earns a salary and deposits it in an account in his name, it is his asset. If the wife buys a house with her income and takes title in her name, it is her asset. Joint assets are owned by both spouses, but only because both names appear on the title.

This system would leave non-earning or lower-earning spouses vulnerable at death, so common law states provide the elective share as a safety net. The surviving spouse can elect to receive a statutory portion of the deceased spouse's estate — typically one-third to one-half — regardless of the will or trust provisions. This right cannot be overridden by the estate plan unless the surviving spouse has waived it in a prenuptial or postnuptial agreement.

The Estate Planning Impact

In a community property state, each spouse can only direct their half of community property at death. A husband cannot leave all of the couple's investment portfolio to his children from a prior marriage — only his 50% share. The other 50% already belongs to his wife. He can, however, leave all of his separate property (assets owned before the marriage or received by gift or inheritance) to his children.

In a common law state, the spouse who holds title controls the asset — but the surviving spouse can override the estate plan through the elective share. This makes prenuptial agreements particularly important in common law states for blended families: without an elective share waiver, the surviving spouse can claim a substantial portion of the estate regardless of the deceased spouse's intentions.

Transmutation: The Accidental Conversion

Transmutation occurs when separate property is converted into community property (or vice versa) through commingling, agreement, or conduct. This is one of the most common — and most expensive — estate planning mistakes in community property states.

A wife inherits $200,000 from her mother. The inheritance is separate property. She deposits it into a joint bank account with her husband and uses it to pay household expenses, make joint investments, and fund home improvements. Over time, the separate property has been so thoroughly commingled with community property that it can no longer be traced. The entire amount has been transmuted into community property — and her husband now owns half of it.

Preventing transmutation requires discipline: maintaining separate accounts for separate property, documenting the source of funds used for separate property investments, and — in many states — executing written transmutation agreements when separate property is intentionally converted to community property.

The Stepped-Up Basis Advantage

One of the most significant financial advantages of community property is the double stepped-up basis at the first spouse's death. Under IRC Section 1014(b)(6), when one spouse dies, both halves of community property receive a stepped-up basis to fair market value — not just the deceased spouse's half.

This can produce dramatic tax savings. If a couple purchased stock for $100,000 that is now worth $1,000,000, the unrealized gain is $900,000. In a common law state, only the deceased spouse's half ($500,000) receives a stepped-up basis. The surviving spouse's half retains the original $50,000 basis, meaning a sale would trigger $450,000 in capital gains. In a community property state, both halves receive a stepped-up basis to $1,000,000 total, and the surviving spouse can sell with zero capital gains.

Moving Between Property Systems

Couples who move from a common law state to a community property state (or vice versa) face additional complexity. Property that was separate under the old state's law may retain its character or may be reclassified under the new state's rules. Some community property states treat property brought from common law states as "quasi-community property" — treated as community property for distribution purposes at death or divorce.

A comprehensive estate plan review is essential whenever a couple moves between property systems. Assumptions that were valid in the old state may be wrong in the new one, and the estate plan must be updated accordingly.

The Bottom Line

Whether a couple lives in a community property state or a common law state determines the starting point for every estate planning decision: who owns what, what each spouse can direct at death, and what rights the surviving spouse has regardless of the estate plan. Understanding this foundation is not optional — it is the prerequisite for everything else in the estate plan.

Blended families in community property states must be particularly careful about transmutation and the 50/50 ownership rule. Blended families in common law states must be particularly careful about the elective share and beneficiary designations. Both systems have advantages and traps, and the estate plan must be designed for the specific system that applies.