Wealth Tax Planning for Family Offices: A 2026 Framework

A Planning Framework for the Policy Environment That Is Already Here

Most conversations inside family offices about wealth taxes begin in the wrong place. They begin with the question of whether proposed taxes will pass, survive legal challenge, or actually collect what their sponsors project. Those are legitimate, albeit secondary questions. The more consequential question is what the existence of this policy environment, regardless of any single outcome, demands of a family office that intends to remain well-positioned over the next 15 years.

The answer is not found in the specific mechanics of Mayor Mamdani’s pied-à-terre surcharge, the Ultra-Millionaire Tax Act pending in Congress, or California’s November ballot initiative. The underlying condition is a durable political consensus, building across jurisdictions and party lines at the state level, that concentrated private wealth represents an undertaxed and underleveraged resource for public fiscal purposes. That consensus is not going away and it is producing a legislative environment in which the rules governing wealth transfer, charitable giving, and portfolio structure are in motion in ways they have not been since the Tax Reform Act of 1986 and the Tax Cuts and Jobs Act of 2017. That exposure compounds alongside wealth itself; as family capital grows, concentration in location-specific, hard-to-move assets deepens dependence on any single jurisdiction’s policy direction. Building structural buffers into the portfolio matters as much as the tax planning around it.

The One Big Beautiful Bill Act (OBBBA), signed into law on July 4, 2025, is instructive precisely because it is not a wealth tax. It is a Republican-authored tax package and it still meaningfully reduced the value of high-income charitable giving by capping itemized deduction benefits at 35 cents per dollar for top-bracket filers, down from 37 cents, and introducing a new 0.5% adjusted gross income (AGI) floor below which charitable gifts produce no deduction at all. The direction of travel is consistent across both parties: the after-tax cost of concentrated private wealth, including the cost of deploying it philanthropically, is rising. Family offices waiting for the legislative environment to clarify itself before adjusting their planning are already behind.

The direction of travel is consistent across both parties: the after-tax cost of concentrated private wealth is rising.

The wealth tax moment does not arrive as a single event but three overlapping pressures operating on different time horizons, each of which demands a different, commensurate response. Family offices that address each clearly will find they have more flexibility than the headline issue suggests.

For family offices with active philanthropic programs, the OBBBA’s 0.5% AGI floor on charitable deductions means that a family with $10 million in annual adjusted gross income receives no deduction for the first $50,000 given to charity. At $20 million AGI, the floor is $100,000. The first six figures of annual giving now produce no income tax benefit for most high-income families. Combined with the 35-cent cap on the marginal value of deductions above that floor, the structural economics of large-scale philanthropy have shifted materially.

This does not mean family offices should give less, simply that the vehicles and timing of giving require reconsideration. Donor-advised funds (DAFs), funded in years of peak income with distributions spread over time, are among the vehicles worth reviewing with qualified tax counsel for families seeking to balance deductibility timing with giving flexibility. However, charitable remainder trusts (CRTs) and charitable lead trusts (CLTs) deserve renewed attention as structures that can balance family income needs, estate-planning objectives, and philanthropic intent across a longer horizon than annual giving programs typically accommodate. Qualified charitable distributions (QCDs) from IRAs, available to those 70½ and older, reduce AGI directly and sidestep both the floor and the cap entirely.

One countervailing provision deserves note: the OBBBA also raised the federal estate and gift tax exemption to $15 million per individual ($30 million per married couple), with inflation adjustments going forward. For family offices whose giving programs were historically motivated in part by estate-tax reduction, the calculus has shifted; there is less immediate estate-tax pressure to give, but more income-tax pressure to give strategically.

Washington State’s 9.9% income tax on earnings above $1 million, signed into law in March 2026 and effective in 2028, is the most significant development in state-level wealth taxation since Washington’s own 7% capital gains excise tax enacted in 2021 and upheld by the state Supreme Court in 2023. It matters not only for the families it directly affects, but as a proof of concept. A state without an income tax built the legal infrastructure to impose one, the courts upheld it, and the legislature immediately extended the architecture further; such a template is transferable.

The behavioral evidence is already visible. In California, six of an estimated 214 billionaires departed before the proposed wealth tax’s residency cutoff, removing an estimated $27 billion in potential tax revenue before the initiative had qualified for the ballot. New York’s share of the nation’s millionaires dropped from 12.7% to 8.7% between 2010 and 2022, with the Citizens Budget Commission estimating that the shrinking share cost the state $10.7 billion in foregone personal income tax revenue in 2022 alone.

These numbers are not arguments for or against wealth taxes. They are evidence that families are already making geographic decisions in response to the policy environment, and those decisions have consequences for state revenues, the philanthropic ecosystems of the metros those families leave, and the portfolio and planning structures those families carry with them.

This mobility is also being driven not just by the legislation itself but the rhetoric surrounding it. The political signal, independent of any specific enactment, is functioning as a behavioral trigger. For a growing number of families, the calculus has shifted from optimizing outcomes to buying certainty: paying taxes now rather than facing an uncertain, but likely higher future liability.

Geographic planning is not new to family offices, but what is new is the speed and scope of the policy change requiring it. A family that established domicile in a low-tax state a decade ago and has not revisited the question since may be operating on assumptions that no longer reflect the legal landscape. State residency rules are increasingly contested and increasingly litigated; the family that relocates but retains significant economic ties to a high-tax jurisdiction, property, business interests, trust relationships, may find that relocation achieves less than anticipated.

This is the pressure most family offices are not yet discussing because it sits at the intersection of planning and values, whereas most advisors are more comfortable with the former.

Wealth taxes, by definition, are premised on the argument that concentrated private wealth is undertaxed and public institutions, rather than private philanthropic ones, are the appropriate vehicle for addressing large-scale social needs. Family offices with active philanthropic programs are implicitly operating on the opposite premise, that private, values-aligned capital deployment, directed by the family and their advisors, produces better outcomes than state-directed redistribution.

For families that have not yet formalized a philanthropic strategy, this moment has a clarifying quality. The tax environment is less favorable to giving than it was five years ago. If a family’s giving program has depended primarily on tax incentives rather than on a genuine articulation of philanthropic intent, this is the moment that becomes visible. Families that give because they believe in the mission of the institutions they support will continue, while those that give primarily because it was tax-efficient may find their motivation compressed (along with their deductibility).

However, there is an asymmetric opportunity here. The community foundations, nonprofit institutions, and mission-driven organizations that family philanthropy has historically supported are under significant structural pressure from multiple directions simultaneously, such as federal funding contractions, policy uncertainty, and shifting donor behavior. The families and family offices that show up with clear intent and long time horizons, not just annual gift decisions, will have an outsized ability to shape the institutions they care about. That ability is not diminished by a less favorable deductibility environment; it is, if anything, clarified by it.

The families that show up with clear intent and long time horizons will have an outsized ability to shape the institutions they care about. That ability is not diminished by a less favorable deductibility environment. It is clarified by it.

The policy environment reshaping the cost of philanthropic giving also has direct implications for how family offices should be thinking about the portfolios that generate that wealth.

The most immediate intersection is estate planning. With the estate and gift tax exemption now at $15 million per individual, made permanent by the OBBBA rather than subject to the scheduled sunset that had been looming since 2017, family offices have a broader and more predictable window for intergenerational wealth transfer than has existed in decades. Assets with high appreciation potential may be transferable through vehicles such as grantor retained annuity trusts (GRATs), spousal lifetime access trusts (SLATs), or similar structures, potentially removing future appreciation from the taxable estate at current valuations. Families with estates above the exemption threshold should consult qualified legal and tax counsel to assess whether current conditions are relevant to their specific circumstances; permanent in tax policy is always a function of the next legislative cycle.

A distinct question for family offices is how to integrate a tax-exempt portfolio, such as assets held within a nonprofit or foundation structure, into an overall tax-aware wealth-management framework. Family offices routinely oversee capital across both taxable and tax-exempt entities, and the structures that optimize outcomes for one do not automatically translate to the other. Advisers with experience managing institutional endowment and foundation capital alongside taxable family portfolios are better equipped to address this directly. The diversification benefits of institutional-quality manager access are real, but they do not, on their own, resolve the structural differences in tax treatment, liquidity demands, and spending policy that govern each pool.

The portfolio conversation with family offices increasingly centers on tax-loss harvesting, where the execution gap is meaningful. A small minority of registered investment advisers has a systematic strategy; of those that do, most execute it with limited sophistication. Hedge funds and active extension strategies are among the most effective vehicles for generating tax losses with discipline, but accessing them requires manager relationships that many advisers do not have. Family office portfolios are also structurally more aggressive in alternatives than institutional endowments, with allocations of 40% or more to private equity, hedge funds, and real assets common among sophisticated offices; advisers working with family capital need to be equipped to operate within that framework.

The family offices best positioned to navigate this environment are not the ones with the most aggressive tax-minimization strategies but those with the clearest alignment between their investment objectives, philanthropic intent, and planning structure. Here are five questions worth putting on the table to ensure such cohesion:

1. Has your charitable giving program been reviewed in light of the OBBBA’s structural changes? The 0.5% AGI floor and the 35-cent deductibility cap are not marginal adjustments. For a family with $20 million in annual income and a $500,000 giving program, the first $100,000 of that program now produces no income-tax benefit. The vehicle and timing question deserves a dedicated conversation, not a footnote in the annual tax review.
2. Is your domicile and residency structure current? Washington State’s 9.9% millionaires’ tax, effective 2028, is the leading edge of a wave. Families in any state actively considering high-income surcharges should be reviewing residency structures, before effective dates arrive and legal scrutiny of residency claims intensifies.
3. Are you using the current estate and gift tax exemption intentionally? The $15 million per individual exemption is permanent under current law, but “permanent” in tax policy is always subject to future legislative action. Families with estates above the exemption threshold that have not updated their transfer planning in the past few years may be leaving significant opportunity on the table.
4. Does your portfolio reflect your full set of objectives, not just your return targets? A family with a long-term philanthropic commitment has different liquidity needs, a different time horizon, and a different relationship to risk than one optimizing purely for accumulation. If that distinction is not visible in your current asset allocation and manager selection, it should be.
5. Do you have a philanthropic strategy, or a giving history? These are different things. A strategy articulates intent, identifies the institutions and causes the family believes in, and structures giving vehicles to sustain that intent across market cycles, tax environments, and generational transitions. Whereas a giving history is a record of annual decisions made under varying conditions. The current environment rewards the former and exposes the latter.

None of these questions require certainty about the legislative future, only clarity about what is already in place and a frank assessment of what the family actually intends. The family offices best positioned to navigate this environment will be those that treat the current policy moment not as a threat to be managed but as an opportunity to build the kind of integrated plan that serves the families across whatever comes next.