What Happens to Stock Options and RSUs in a Divorce?

If you or your spouse works in tech, finance, or at any company that uses equity as part of compensation, stock options and RSUs are likely sitting somewhere in your marital estate — sometimes worth more than the house. These assets are real, they're valuable, and they're among the most commonly mishandled in divorce negotiations. The math isn't obvious, the tax rules are counterintuitive, and the choices you make about unvested grants affect both spouses for years after the divorce is final.

This article explains how equity compensation works, how courts calculate the marital share, and what happens to the tax bill when these assets are divided.

RSUs vs. Stock Options — What's the Difference?

These two types of equity compensation work very differently, and that difference matters in divorce.

RSUs (Restricted Stock Units) are shares of company stock the company promises to give you on a future date, usually tied to a vesting schedule. You don't pay anything to receive them — you just wait for them to vest. When they vest, you receive actual shares (or cash equivalent), and that value is taxed as ordinary income at the moment of vesting. RSUs have real, calculable value as long as the company's stock has a price.

Stock options give you the right to purchase company stock at a fixed price (called the exercise or strike price) at some future date. Their value depends on whether the stock price rises above that strike price. There are two federally recognized types, and they are treated very differently in divorce.

Marital vs. Separate Property: The Core Question

The starting point for any equity grant is the same question courts ask about every asset: was it earned during the marriage? If a grant was awarded entirely during the marriage and vested before the date of separation, it's marital property — straightforward to classify, if not always easy to divide.

The complexity arises when a grant spans the date of separation or the date of divorce. This is extremely common, because most equity grants vest over three to four years. A grant made two years into a five-year marriage might still be vesting two years after the divorce is final. That grant is partly marital, partly separate — and courts need a formula to split it.

The Coverture Fraction: How Courts Calculate the Marital Share

Courts across the country use a time-based formula — called the coverture fraction or the time rule — to calculate what portion of a stock grant is marital property. The concept is straightforward: the marital share is proportional to how much of the vesting period fell within the marriage.

The basic formula is:

The resulting fraction is then multiplied by the number of shares in the grant. That number — the marital share — is what goes into the marital estate to be divided. The rest is the employee spouse's separate property.

The Hug formula and the Nelson formula

California courts developed two specific variations of the time rule, each named after the appellate case that established it. These formulas are widely cited and followed in other states as well.

The Hug formula applies when a grant was made to reward past service — essentially as a bonus for work already done. Because the grant compensates for the entire employment period up to the grant date, the marital share is calculated from the date of hire (or the start of the relevant employment period) to the date of separation, divided by the total period from hire to vesting.

The Nelson formula applies when a grant was made to incentivize future service — to keep the employee engaged going forward. Because the grant is about future work, the relevant period starts at the grant date, not the hire date. The marital share runs from the grant date to the date of separation, divided by the grant date to the vesting date.

Whether a grant was intended as past or future compensation depends on the grant agreement, the company's stated purpose, and sometimes testimony about how the equity program works. In practice, many grants fall somewhere in the middle and courts have discretion in choosing which formula fits best. Both spouses' attorneys will often argue for the formula that produces a more favorable result for their client.

Three Ways to Divide Equity in a Settlement

Once the marital share is calculated, there are three practical approaches to dividing it.

1. Immediate offset

The employee spouse keeps all the equity. In exchange, the non-employee spouse receives an equivalent value in other marital assets — cash, retirement accounts, home equity. This is the cleanest outcome: no ongoing entanglement, no future interaction required. The catch is that it requires having enough other liquid assets to offset the equity value, and it requires agreeing on what that value is today — which can be contested if the stock price is volatile or the company is private.

2. In-kind division of vested shares

Vested shares can simply be transferred — the non-employee spouse receives their portion of actual shares, which they can hold or sell. This avoids the valuation dispute of an offset and gives the non-employee spouse direct exposure to the stock. It requires the company's cooperation and a properly drafted court order specifying the transfer. Many companies have their own standard forms for this.

3. "If, as, and when" — deferred division for unvested grants

When grants haven't vested yet, it's often impractical to value or transfer them today. The "if, as, and when" approach defers the division: as each tranche vests and the employee spouse receives shares or cash, the non-employee spouse receives their calculated percentage at that time. This approach preserves both spouses' economic interest in the grant but requires ongoing communication and a detailed court order spelling out the exact percentage, the timing of transfers, and how taxes are handled.

The ISO Transfer Trap

Incentive Stock Options (ISOs) receive preferential tax treatment under federal law — specifically, no ordinary income tax is owed at exercise, and gains are taxed at capital gains rates when the stock is sold. This makes ISOs significantly more valuable than NQSOs on an after-tax basis.

The catch: ISOs can only be held by the employee who earned them. Transferring an ISO to anyone else — including a spouse in a divorce — automatically disqualifies it, converting it into a non-qualified stock option (NQSO). The preferential tax treatment is permanently lost.

This means the non-employee spouse cannot simply receive ISOs. The choices are to offset the ISO value against other assets (keeping the ISOs with the employee spouse), to exercise the ISOs before the divorce (converting them to shares that can be divided), or to accept that the non-employee spouse's share will be based on the after-disqualification value as NQSOs. All three approaches have different tax consequences that need to be modeled before a decision is made.

Who Pays Tax When Equity Is Divided?

The tax rules for equity division in divorce are counterintuitive and specific. Getting them wrong can result in one spouse owing a tax bill for income the other spouse receives.

NQSOs: the non-employee spouse pays on exercise

Under IRS Revenue Ruling 2002-22, transferring NQSOs to a non-employee spouse incident to divorce is not a taxable event for the employee spouse — consistent with the general IRC § 1041 rule for property transfers in divorce. But when the non-employee spouse later exercises those options, they — not the employee spouse — recognize ordinary income equal to the spread between the strike price and the fair market value on the exercise date. The non-employee spouse is also responsible for FICA taxes on that amount, as if they had been the one who performed the services.

This matters in two ways. First, the employee spouse needs to understand they won't owe income tax on the non-employee spouse's exercise. Second, the non-employee spouse needs to understand they will owe ordinary income tax — potentially at a high rate — when they exercise, and should plan for it accordingly.

RSUs: withholding happens at vesting

When RSUs vest, the company withholds shares (or cash) to cover the employee's income tax liability. This withholding happens at the employee spouse's tax rate. If the settlement uses an "if and when" approach and the non-employee spouse is entitled to a percentage of vested RSUs, the question of how that withholding is handled must be explicitly addressed in the settlement. The non-employee spouse often receives their share of the after-tax, after-withholding proceeds — meaning they get fewer shares than the gross percentage would suggest. Some settlements negotiate for a gross-share split with each spouse bearing their own tax consequences.

ISOs: no ordinary income tax at exercise (unless AMT applies)

For ISOs that remain with the employee spouse (not transferred), the employee owes no regular income tax when they exercise — only when they sell the shares. However, the spread at exercise is an Alternative Minimum Tax (AMT) preference item, which can create a significant AMT liability in the exercise year. This is a planning consideration for the employee spouse that can affect the net value of the ISOs.

Private Company Stock: An Additional Layer of Complexity

Everything above assumes a publicly traded company where shares have a real-time market price. For employees at private startups and pre-IPO companies, the picture is harder. Private shares have no liquid market, so valuation requires either a 409A valuation (the company's own internal assessment) or an independent appraisal. The value can be highly uncertain, and in many cases the shares cannot be sold or transferred without the company's consent.

For unvested private company grants, many attorneys default to the "if and when" approach — deferring division until a liquidity event (IPO, acquisition, or secondary sale) makes the value real and transferable. The settlement needs to specify what counts as a liquidity event, what percentage the non-employee spouse receives, and what happens if the company fails and the grants become worthless.