JTWROS is the default titling choice for most married couples, yet it contains legal and tax traps. Adding a non-spouse as a joint tenant (e.g., adding an adult child to a bank account for convenience) is treated as a taxable gift under IRC §2503 if the new owner withdraws funds for their own benefit, or immediately upon the creation of a joint brokerage account where the new owner can trade. This can trigger gift tax reporting obligations once transfers exceed the annual exclusion limit ($19,000 for 2025 and 2026).
The Cost of the Wrong Title. The fractional step-up associated with JTWROS carries a severe, measurable tax penalty for married couples holding highly appreciated portfolios. Consider a couple who established a $1,000,000 brokerage portfolio that has appreciated to a $5,000,000 fair market value. Upon the death of the first spouse, the survivor decides to reallocate the holdings to mitigate factor risk.
If the account is titled as JTWROS, only the decedent’s 50% share receives a basis step-up to current fair market value. The survivor’s new basis is $2,500,000 (the stepped-up half) plus $500,000 (their original cost basis in the survivor’s half), totaling $3,000,000. Selling the portfolio to reallocate immediately realizes a taxable capital gain of $2,000,000.
If the account is instead titled as Community Property—or community property with right of survivorship— IRC §1014(b)(6), “Basis of property acquired from a decedent” steps up both halves of the property to the full $5,000,000 value upon the first spouse’s death. The survivor’s basis becomes the full $5,000,000, and subsequent liquidation realizes zero taxable gain. At a 23.8% federal tax rate (the 20% maximum long-term capital gains rate plus the 3.8% Net Investment Income Tax), this simple titling decision yields $476,000 in federal tax savings—excluding additional state-level income taxes.
For residents of common-law states, this double step-up is generally unavailable through standard joint titling, though some states permit the use of community property trusts to secure the same tax treatment. See section “Capital Gains Resets With Inheritance” for step-up mechanics.