The core question: how do you split something that was partly earned before, during, and after marriage?

Carried interest rarely fits neatly into “community” or “separate” property. A fund professional might join a firm before marriage, continue working through the marriage, and still be waiting for distributions after separation. The carry was “earned” across all of those periods — so how do you figure out the community’s share?

That’s the job of the forensic accountant, and the tool they use is an apportionment methodology. Think of it as a formula for allocating value across time. Different methodologies emphasize different factors, and the choice of methodology can swing the community’s share by millions of dollars.

Understanding these approaches isn’t optional. It’s essential for evaluating your expert’s work — and for anticipating what the other side’s expert might argue.

The Nelson methodology

How it works

The Nelson methodology (sometimes called the “Nelson fraction”) allocates carried interest based on the proportion of time the spouse worked at the fund during the marriage relative to the total time they worked at the fund.

The basic formula is:

Community Share = (Months of fund employment during marriage) ÷ (Total months of fund employment) × Total carry value

When it’s used

Nelson is most commonly applied when a fund professional was employed at the same firm before, during, and after the marriage. It’s a time-based allocation that treats each month of employment as contributing equally to the carry earned.

A composite example

A vice president joined a fund in January 2015 and separated from their spouse in January 2023. They married in January 2018. Their total carry allocation across two funds is projected to be worth $3 million.

Total employment: 96 months (Jan 2015 – Dec 2022, for this analysis)
Employment during marriage: 60 months (Jan 2018 – Dec 2022)
Nelson fraction: 60/96 = 62.5%
Community share: $3M × 62.5% = $1,875,000

Strengths and limitations

Strengths: Simple, transparent, and easy for a judge to understand. Works well when the spouse’s role and contribution were relatively consistent over time.

Limitations: Treats all months equally, which can be unfair if the spouse’s contributions changed significantly over time (e.g., they were junior early on and became a deal-leading partner during the marriage). Doesn’t account for when specific deals were sourced, executed, or exited.

The life of the fund approach

How it works

Instead of focusing on the employee’s tenure, the life of the fund approach allocates carry based on the overlap between the marriage and each fund’s lifecycle. Each fund is analyzed separately.

Community Share (per fund) = (Months of marriage during fund’s active life) ÷ (Total months of fund’s active life) × Carry value from that fund

The “active life” typically runs from the fund’s first close (when capital commitments are finalized) to its final distribution or wind-down.

When it’s used

This approach is particularly useful when a fund professional has carry in multiple funds at different stages. A spouse might have carry in Fund II (fully harvested), Fund III (in the distribution phase), and Fund IV (still investing). Each fund’s community share is calculated independently based on its own timeline.

A composite example

A partner holds carry in three funds. The marriage lasted from 2017 to 2024.

Fund II (2014–2021, fully exited): 7 years active, 4 years overlapping with marriage. Community fraction: 4/7 = 57%. Carry value: $800K. Community share: $456K.
Fund III (2018–2026, projected): 8 years active, 6 years overlapping with marriage. Community fraction: 6/8 = 75%. Projected carry value: $1.2M. Community share: $900K.
Fund IV (2021–2029, projected): 8 years active, 3 years overlapping with marriage. Community fraction: 3/8 = 37.5%. Projected carry value: $1.5M. Community share: $562K.
Total community share: $1,918,000

Strengths and limitations

Strengths: More granular than Nelson because it accounts for the timing of each fund’s activity. Recognizes that carry from a fund launched after separation shouldn’t be community property.

Limitations: Requires projecting fund timelines and end-of-life values, which introduces estimation uncertainty. The definition of “active life” can be disputed — does it start at first close, final close, or first investment?

The time rule of marriage

How it works

The time rule is a broader apportionment method borrowed from pension and stock option case law. It applies a fraction based on the period of marriage during which the asset was being earned, divided by the total earning period.

For carried interest, the formula typically looks like:

Community Share = (Date of marriage to date of separation) ÷ (Date carry was first allocated to date carry is fully realized) × Total carry value

When it’s used

The time rule is often applied when the carry allocation happened during the marriage but will take years to fully vest and pay out. It’s particularly relevant for younger fund professionals who received their first carry allocation after getting married and are still waiting for fund exits at the time of divorce.

A composite example

A principal received their first carry allocation in Fund III in March 2019, one year after their marriage in March 2018. The couple separated in March 2024. The fund is projected to make final distributions in 2028.

Total earning period: March 2019 to March 2028 = 108 months
Marriage overlap with earning period: March 2019 to March 2024 = 60 months
Time rule fraction: 60/108 = 55.6%
Projected carry value: $2M. Community share: $1,112,000

Strengths and limitations

Strengths: Well-established in family law from pension and stock option precedent. Judges are familiar with the framework.

Limitations: Defining the “start” and “end” of the earning period is inherently debatable. The fund professional might argue the earning period extends well past separation (reducing the community fraction), while the non-fund spouse might argue it should end at separation (maximizing the community fraction).

Hybrid approaches

In practice, many forensic accountants use hybrid approaches that combine elements of multiple methodologies. Common hybrids include:

Deal-by-deal attribution

Instead of using time-based fractions, this approach attributes carry to specific deals and then determines whether each deal was sourced, executed, or exited during the marriage. It’s the most granular method but also the most data-intensive and expensive.

Weighted time allocation

Rather than treating all months equally (as pure Nelson does), a weighted approach gives more credit to periods of greater contribution. For example, the investment period (when deals are being sourced and executed) might receive 60% of the weight, while the harvest period (when deals are being exited) receives 40%.

Blended fund-level and individual-level

Some experts combine the life of the fund approach (for timing) with a Nelson-style individual analysis (for the employee’s contribution). This can capture both the fund’s lifecycle and the individual’s changing role over time.

When each methodology favors which spouse

This is the strategic reality: methodology choice isn’t just a technical question. Different approaches tend to favor different parties.

Nelson tends to favor the non-fund spouse when the fund professional has been at the firm for a long time and the marriage covers a large portion of that tenure. It treats all time equally, so seniority during the marriage (and presumably higher contributions) gets the same weight as junior years.
Life of the fund tends to favor the fund professional when newer funds (launched during or after the marriage) are projected to be the most valuable. The community’s share of newer funds will be smaller because less of the fund’s life overlapped with the marriage.
The time rule can favor either side depending on how the earning period is defined. A longer projected earning period dilutes the community’s share.
Deal-by-deal attribution can favor either side depending on when the most valuable deals occurred. If the biggest winners were sourced during the marriage, this method benefits the non-fund spouse.

How opposing experts disagree (and why)

In a contested divorce with significant carry, each side will typically retain its own forensic accountant. It’s common — even expected — for these experts to reach different conclusions. Here’s why:

Methodology selection: Expert A uses Nelson; Expert B uses life of the fund. The community share differs by 15%.
Date definitions: Both experts use the time rule, but they disagree on when the “earning period” begins. One says the date of hire; the other says the date of carry allocation.
Discount rates: Both experts agree on the community fraction, but they apply different discounts for illiquidity and risk. One applies a 20% discount; the other applies 35%.
Future projections: Both experts use life of the fund, but they project different fund lifespans and exit values based on different assumptions about portfolio company performance.

This isn’t a flaw in the system — it’s the nature of valuing a complex, illiquid asset. The judge (or mediator) will evaluate which expert’s assumptions and methodology are most reasonable and well-supported.

What to do next

Get a baseline estimate. Use the CarryForward calculator to model your carried interest’s potential value range before engaging experts.
Ask your forensic accountant which methodology they plan to use and why. If they can’t explain their choice in plain English, that’s a red flag.
Understand the other side’s likely approach. If your spouse’s expert uses a different methodology, you need to understand why it produces a different number — and whether those differences are defensible or exploitable.
Don’t accept a single number. Any credible apportionment should present a range. If your expert gives you one number with no sensitivity analysis, push back.

Apportionment methodology isn’t just accounting — it’s strategy. Understanding these frameworks puts you in a stronger position to evaluate your expert’s work, challenge the other side’s assumptions, and negotiate from knowledge rather than uncertainty.

Apportionment Methodologies: Nelson, Life of the Fund, Time Rule, and More

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