Arizona now has a postnup law — what married couples should know

Prenuptial agreements have gone mainstream: a Harris Poll released this summer found 53% of engaged or married people under 45 said they’d signed one. But what about couples who are already married?

Since September 12, 2026, Arizona has a statute written specifically for postnuptial agreements — agreements spouses make during the marriage.

The new law

HB 2861 (Laws 2026, Ch. 26), approved April 7, 2026, added A.R.S. § 25-202.01 and updated the related marital-agreement statutes. Its core requirements:

• The agreement must be in writing and signed by both spouses.
• It takes effect when both have signed.

How a postnup can be challenged

A spouse who wants to avoid enforcement must prove — by clear and convincing evidence, a high bar — one of the following:

Ground	What it looks like
Fraud, coercion or undue influence	Pressure, deception, threats
Lack of full knowledge of the property	Hidden assets or debts
Not fair and equitable	A lopsided result
No mutual intent	One spouse didn’t really agree

Full financial disclosure is the single best protection for everyone. An agreement built on a complete picture is much harder to attack.

What it can and can’t cover

• Can: divide property, address debts, and modify or eliminate spousal maintenance.
• Can’t: adversely affect a child’s right to support. Child support is the child’s right, not the parents’ to trade away.

Related: spousal maintenance guidelines

Arizona’s spousal maintenance guidelines were amended effective September 1, 2025. If your agreement addresses maintenance, the current guidelines are a useful benchmark for what a court would otherwise consider.

Should you get one?

Couples consider postnups after an inheritance, a business launch, a move between states, or a rough patch they’ve worked through. Each spouse having their own attorney review the agreement is the most reliable way to make sure it holds up.

---