Washington's New Income Tax: The Complete Guide for Founders, Investors, and High Earners

Key Takeaways

• 9.9% tax on AGI above $1 million, effective 2028
• Two‑year window for restructuring, exits, and domicile moves
• Marriage penalty applies at household $1 million threshold
• QSBS gains remain exempt, offering tax shelter for founders
• Legal challenge could delay or overturn the tax

Pulse Analysis

Washington’s new income tax marks a watershed moment for a state that has long relied on sales and business‑and‑occupation taxes. ESSB 6346 imposes a 9.9% rate on adjusted gross income above a $1 million threshold, with the first payments due in 2028. The legislation follows a series of failed local attempts and reflects a broader trend of states seeking new revenue streams amid infrastructure needs. While the tax is framed as a "millionaire tax," its household‑level threshold and lack of exemptions for most income types broaden its reach far beyond ultra‑wealthy individuals.

For the tech ecosystem, the tax reshapes compensation and exit planning. Stock options, RSUs, and other equity awards now face ordinary‑income treatment once the threshold is crossed, prompting founders and executives to accelerate exercises or consider alternative structures such as C‑corps versus pass‑through entities. Washington’s Pass‑Through Entity (PTE) election offers a limited workaround, but the marriage penalty—where married couples share the $1 million cap—adds another layer of complexity. Notably, Qualified Small Business Stock (QSBS) gains remain exempt, preserving a valuable tax shelter for startup founders and early investors and influencing decisions around Section 1202 planning.

The two‑year horizon before 2028 creates a strategic sprint. Professionals are advised to evaluate domicile changes, leverage Roth conversions, and employ charitable giving or tax‑loss harvesting to keep AGI below the threshold. Real‑estate investors must consider 1031 exchanges, while crypto holders face new reporting obligations. Meanwhile, a fast‑tracked legal challenge raises the possibility of a delayed or revised tax, adding uncertainty to long‑term planning. Stakeholders should monitor court developments and state guidance closely, while proactively adjusting structures to mitigate the upcoming fiscal impact.