Short answer: It depends entirely on what the trust document says — and the document usually says two different things about two different halves. In a typical California joint trust, the surviving spouse keeps full power to amend his or her own share, while the deceased spouse’s share often becomes irrevocable the moment the first spouse dies. If the trust is silent, Probate Code §§15401–15402 fill the gap. There is no universal yes or no here; the answer is printed in your trust’s amendment and revocation clause.
Code sections verified against the California Probate Code, 2026. This is general information, not legal advice for your situation.
Your spouse died three months ago. You’re the surviving trustee of the joint living trust you both signed years back, and now you want to change something — maybe update who inherits, maybe swap out a successor trustee who’s no longer a good fit. Can you? Before anyone answers that question, they need to read your trust. Here’s what they’re looking for, so you can look for it yourself first.
What the law says when the trust doesn’t
California’s default rules are in Probate Code §15401 (revocation) and §15402 (modification). Boiled down: a revocable trust can be revoked or amended by the method the trust document spells out, and if the document spells one out and makes it exclusive, that method is the only way. If the document is silent, the statute’s fallback — a signed writing delivered to the trustee — works.
But those defaults only matter for the part of the trust that’s still revocable. The real question for a surviving spouse is: which part is that? And that’s a document question, not a statute question.
The clause to find in your trust
Pull out the trust and find the section titled something like “Revocation and Amendment” or “Rights Reserved by the Settlors.” It usually sits in the first ten pages. You’re looking for language answering three things:
- What happens at the first death? Does the trust stay one pot, or split into shares (often labeled Survivor’s Trust, Bypass Trust, Exemption Trust, Trust A/Trust B)?
- Which shares stay amendable? Nearly every joint trust keeps the survivor’s own share fully amendable. The deceased spouse’s share is the coin flip.
- Is there a method requirement? Some trusts require amendments to be notarized or delivered a specific way. If the trust makes its method exclusive, follow it exactly.
Now match your trust to one of the three common patterns.
Three trusts, three different answers
Scenario 1: The modern all-to-survivor trust. A Camarillo couple signs a joint trust in 2019. At the first death, everything continues in one revocable pot for the survivor. The survivor can amend or revoke the whole thing — change beneficiaries, change trustees, start over. This is the most common design today: with the federal estate tax exemption at $15 million per person (permanent, and California has no state estate tax), most families no longer need the old tax-driven split. If you want to change something, you likely can — the practical question becomes whether to do an amendment or a full restatement.
Scenario 2: The old A/B trust. A couple signed their trust in 1998, when the exemption was a fraction of today’s. At the first death, the document requires a split: the survivor’s half goes into an amendable Survivor’s Trust (Trust A), and the deceased spouse’s half locks into an irrevocable Bypass Trust (Trust B). The survivor can freely change Trust A. Trust B is frozen — the deceased spouse’s beneficiary choices are now set, and the survivor typically gets income and limited access but no power to rewrite who inherits. If this is you, two thoughts: first, the lock may be doing nothing but generating accounting work, since the tax reason for it is mostly gone — read whether you still need your A/B trust. Second, an irrevocable share isn’t always hopeless; California has procedures for modifying irrevocable trusts in the right circumstances — see changing an irrevocable trust in California.
Scenario 3: The blended-family trust. Each spouse has kids from a prior marriage. The trust deliberately makes the deceased spouse’s share irrevocable at the first death so the survivor can’t later redirect it away from the deceased spouse’s children. Here the lock isn’t a tax relic — it’s the whole point. The first spouse to die bought certainty that their kids inherit their half. A survivor who tries to amend that share anyway isn’t exercising a right; they’re breaching the trust, and the deceased spouse’s kids can (and do) push back. If you’re the survivor in this setup and something genuinely needs fixing, that’s a conversation to have before acting, not after.
What not to do
Don’t amend first and check later. An amendment signed by a survivor who lacked the power to make it doesn’t just fail — it invites a dispute between the survivor and the deceased spouse’s beneficiaries, and those fights burn money that would otherwise have been inherited. And to be clear about lanes: if a fight over a survivor’s amendment is already headed to court, that’s trust litigation, which isn’t what Eric does — he’ll refer you to a good litigator for free. Reading the trust, telling you plainly what you can and can’t change, and drafting the change correctly if you can — that’s squarely his lane.
Questions people actually ask
Can a surviving spouse change the beneficiaries of a living trust in California?
Only for the portion that remains revocable as to the survivor — usually the survivor’s own share. If the trust locks the deceased spouse’s share at the first death, those beneficiaries are fixed. The trust’s amendment clause, not a general rule of law, decides which situation you’re in.
Does a joint trust become irrevocable when one spouse dies?
Sometimes partly, rarely entirely. Modern all-to-survivor trusts typically remain fully revocable by the survivor. A/B and blended-family trusts typically make the decedent’s share irrevocable while leaving the survivor’s share amendable. Whole-trust irrevocability at first death exists but is uncommon.
What is the difference between the survivor’s trust and the bypass trust?
After a first death under an A/B design, the survivor’s trust (Trust A) holds the surviving spouse’s share and stays amendable and revocable by the survivor. The bypass trust (Trust B) holds the deceased spouse’s share, is irrevocable, and carries out the deceased spouse’s wishes — the survivor usually benefits from it but can’t rewrite it.
Can a surviving spouse revoke a trust under Probate Code §15401?
Section 15401 lets a settlor revoke the revocable portion of a trust, using the trust’s stated method or, if none is exclusive, a signed writing delivered to the trustee. It does not give a survivor power over portions the trust made irrevocable at the first death. The statute governs the how, the document governs the whether.
What if the trust doesn’t say anything about amendments after the first death?
Genuine silence is rare, but if the trust really doesn’t address it, the statutory defaults in §§15401–15402 apply to whatever remains revocable, and the trust’s overall structure — one pot or split shares — becomes the interpretive question. This is worth an hour of a lawyer’s time before you act, because guessing wrong creates exactly the dispute the trust was supposed to prevent.
Can a surviving spouse change the successor trustee?
Usually yes for the survivor’s own share, and many trusts separately give the survivor (or the beneficiaries) a limited power to replace trustees even for the irrevocable share without touching who inherits. Trustee-succession powers are often broader than amendment powers — check whether your trust has a separate trustee-removal or appointment clause.
The bottom line
“Can I change the trust?” has a one-word answer only after someone reads your trust. Survivor’s share: almost always yes. Deceased spouse’s share: yes in a modern all-to-survivor trust, no in most A/B and blended-family designs — and in the blended-family case, that “no” is intentional and enforceable. Find the amendment clause, figure out which pattern you have, and if it’s ambiguous or the stakes are real, get it read professionally before you sign anything. If you’re the surviving spouse and want a straight answer on what your document actually allows, talk to Eric.
Sources: Cal. Prob. Code §15401; Cal. Prob. Code §15402; IRC §2010(c) (federal exemption $15,000,000 per person, permanent, P.L. 119-21).
Want a straight read on where you stand?
Talk to Eric. A free 30-minute call, no pitch. He’ll tell you where you’re exposed, what it would cost to fix, and what you can skip.
Talk to Eric