Structure Determines Your Tax Outcome: Washington State Tax Planning for Founders, Investors, and High Earners

I've spent the last decade advising founders, C-suite executives, and investors in Washington State on entity structure. In that time, I've learned one lesson that towers above all others: the decisions you make at incorporation echo through every future tax event. With Washington's new 9.9% income tax (ESSB 6346) set to take effect January 1, 2028, that lesson has become urgent.

This is not a prediction problem. We know the tax is coming. What we face now is a timing and structure problem. And timing and structure are precisely the domains where thoughtful planning actually works.

This post is part of our Complete Guide to Washington's New Income Tax.

How Entity Structure Determines Your Tax Exposure

Let me walk you through the mechanics. Washington's new income tax applies to capital gains and long-term capital gains with very few exemptions. But here's the crucial part: the tax applies at the shareholder level, not the entity level. This creates a vast difference between a C-corporation, an S-corporation, and an LLC.

If you're operating as a C-corporation, capital gains flow through to shareholders when they exit. Those gains are taxable at the state level at 9.9%. Simple. But if you're an S-corporation or a partnership (including an LLC taxed as a partnership), you're passing through your ordinary income to shareholders as well. That ordinary income is not taxed by Washington—not yet, anyway—but it's taxed at the federal level and by many other states.

This distinction matters enormously. A C-corporation creating and retaining earnings can compound value tax-free at the state level until the shareholder actually realizes a gain. An S-corporation or partnership-taxed LLC does not have this luxury. You're paying federal tax on retained earnings, and your shareholders may be paying state tax on their K-1 allocations in other jurisdictions.

The mistake I see repeatedly is founders choosing an LLC or S-corp for simplicity or because their accountant defaulted to it, without thinking through the long-term tax consequences. That choice seemed neutral in year one. By year five or ten, it has cost them hundreds of thousands of dollars.

The Federal-State Planning Interplay

Most tax planning happens in isolation. Federal tax advisors focus on federal problems. State tax advisors focus on state problems. But they are not separate. They are deeply intertwined, and the best planning holds both in mind.

Consider the double taxation of the C-corporation. Federally, we've lived with this for years. You pay corporate-level tax, then shareholder-level tax on distributions. At the federal level, this has often justified S-corp treatment. But Washington's tax changes the calculation. If you're in Washington, the state-level "second tax" on C-corp capital gains is already there. What you avoid by electing S-corp treatment is federal tax on corporate earnings—but you then expose yourself to federal self-employment tax and create issues in other states.

The right structure for a Seattle founder in 2026 is not the same as it was in 2024. The federal-state calculus has shifted. This is why I'm increasingly advising founders to think about C-corp formation or conversion before 2028, locking in the structure before the new tax regime begins.

Why QSBS Creates a Monumental Advantage for C-Corp Founders

I want to emphasize something that I believe is under-recognized: Section 1202 of the Internal Revenue Code—the QSBS exclusion—is one of the most powerful tax incentives in the entire tax code. It allows you to exclude up to $10 million (adjusted annually) of gains on qualified small business stock from federal taxation, provided you hold the stock for five years and meet certain criteria.

QSBS only applies to C-corporations. It does not apply to S-corporations or partnerships. This alone is a reason to form as a C-corporation if you have any reasonable hope of building valuable intellectual property or a high-growth business.

But here's where it gets interesting in the Washington context: QSBS is a federal exclusion. It excludes the gain from federal tax. Washington's income tax, being new and somewhat unique, is not yet fully settled on how it interacts with federal exclusions. This is genuinely uncertain territory. But the smart assumption is that if you exclude the gain federally, you have a strong argument for excluding it from Washington's tax as well.

If I'm advising a founder who might build something worth $50 million, $100 million, or more, QSBS eligibility is not a secondary consideration. It's foundational. And QSBS requires C-corp status from the beginning. You cannot convert an S-corp or partnership into a QSBS-qualifying C-corp after the fact and have the holding period run from your original formation date.

This is a permanent, irreversible decision. Get it right at the start.

Timing Strategies: Accelerating Income Before 2028

We have roughly 20 months before the new tax takes effect. For some founders and high earners, this window is actionable.

If you have capital gains you know will be triggered in 2028 or 2029—perhaps a strategic exit, a secondary sale, or a vesting cliff—accelerating that realization into 2027 can save substantial tax. A gain of $2 million realized in 2027 is $2 million federal tax only (at whatever your federal rate is). That same gain in 2029 is $2 million federal plus $198,000 in Washington state tax at 9.9%.

For some business owners, this might justify accelerating a sale, or timing a Section 338 election, or structuring a earn-out to land proceeds in 2027 rather than 2028. The math can be stark.

I emphasize "for some." This is not advice to rush a sale or trigger gains unnecessarily. But if you're already planning a transition, the timeline matters. And for investors holding appreciated securities, harvesting gains before the tax takes effect is worth serious analysis. I've already had several clients do this.

Deferral Techniques: Roth Conversions, Installment Sales, and Others

On the opposite end of the spectrum are strategies to defer gains beyond 2028, or to shift them to lower-income years, or to spread them over time.

Roth conversions deserve attention. If you hold a traditional IRA or a SEP-IRA and you have liquidity, converting that IRA to a Roth IRA creates ordinary income in the conversion year, but then all growth is tax-free forever. The ordinary income itself is not taxed by Washington (the state income tax applies to capital gains and certain investment income, not ordinary income). So a Roth conversion can lock in tax-free treatment of future growth that would otherwise be exposed to Washington tax in 2028 and beyond.

This only works if you can pay the conversion tax out of other funds without depleting your retirement savings. But if you have non-retirement assets to cover the tax bill, a Roth conversion in 2026 or 2027 is worth serious consideration.

Installment sales are another tool. If you're selling a business or appreciated asset, structuring the sale as an installment contract allows you to spread the gain over multiple years. This can reduce your federal tax bracket in any given year and, depending on when the payments arrive, might minimize your exposure to the state tax or spread it over years where you have offsetting losses or lower income.

For high-income earners with concentrated positions—say, an executive with a large block of employer stock—collars and exchange funds allow you to hedge downside risk while deferring taxes. These are not new strategies, but they're worth revisiting in light of the new state tax.

The Domicile Question: Staying vs. Leaving Washington

This is a touchy subject, so I'll address it directly. Washington's new income tax applies to capital gains of residents and non-residents who are "physically present" in the state and trigger gains while present. The statute and regulations are still being written, so there's real uncertainty here.

Some high-net-worth individuals are considering leaving Washington before the tax takes effect. I understand the instinct. But I also think it's often oversold and frequently impractical.

First, establishing non-domicile is not easy. Washington will challenge it if you've lived here for years and still have business interests, family, or property here. You have to demonstrate a genuine intent to establish a new domicile and actually reside there. Simply buying a small home in Nevada and claiming you live there while you spend six months in Seattle will not work.

Second, even if you succeed, the tax applies to capital gains triggered while you are physically present in Washington. So if you have business operations or properties in Washington that generate gains, you don't escape the tax by moving. You're only escaping the tax on capital gains triggered outside the state while you're not here.

Third, the relocation itself often creates problems. You may trigger tax liabilities in other states. You may lose access to your business and professional networks. For founders and operators, Washington's proximity to Seattle's venture ecosystem, tech talent, and legal infrastructure is valuable. Moving to avoid a 9.9% tax is a large life decision that should not rest solely on tax savings.

That said, if you've already built a business or made your gains and you're in the harvest phase—taking money off the table and moving to a lower-tax lifestyle—then domicile planning becomes more relevant. It's a tool for the late stage, not the early stage.

Why Structure Decisions Echo Through Every Future Tax Event

I want to circle back to the main point. The structure you choose when you incorporate your company will shape every future tax outcome. This is not hyperbole.

If you form as a C-corporation, you have access to QSBS. You lock in the ability to compound value at the state level. You set yourself up for federal-state planning later. If you form as an S-corp or LLC, you foreclose those options. You may not be able to change course later without triggering unintended tax consequences.

Similarly, the choice of where to incorporate—in Washington, Delaware, Nevada—affects your tax exposure, your regulatory burden, and your legal protections. In Washington particularly, the interaction between Washington's B&O tax (a gross-revenue tax) and the new income tax creates planning opportunities for certain business structures. A service business might operate very differently than a product company.

The point is simple: structure is not a technicality. It's the foundation of everything that follows. Getting it right at the beginning—when the decision is still reversible—is far easier than trying to fix it later.

Moving Forward

We are in a window. The new tax has not taken effect. The regulations are not final. And we still have time to plan. But that window is closing. Every month that passes is a month you cannot get back for timing strategies like income acceleration or Roth conversions.

If you're a founder, an investor, or a high-earning professional in Washington State, now is the time to get intentional about structure and timing. The questions are not technical—they're strategic. They require looking at your business, your income, your assets, and your timeline, and deciding what the tax outcome should be.

I work with clients on precisely these decisions. If this post resonates with you, or if you're uncertain about your own structure and plan, I'd encourage you to dig deeper.

Related Posts

• C-Corp vs. S-Corp vs. LLC: Washington Income Tax Comparison
• Washington's New Income Tax: What Founders, Investors, and High-Earners Need to Know
• Does QSBS Avoid Washington's New 9.9% Income Tax?
• Roth Conversions Before 2028: A Washington Income Tax Strategy
• How to Change Washington Domicile and Avoid the Income Tax
• Washington's New Income Tax: The Complete Guide

Ready to Build on a Solid Legal Foundation?

Strategic structure and tax planning are investments in your future. If you're building a company or managing significant assets in Washington, the decisions you make now will compound for years. Let's talk about the right structure and strategy for your situation.

Get in touch to discuss your entity structure, tax exposure, and planning options.