Washington State Taxes on RSUs and Stock Options: A Tech Employee's Guide

Washington is home to Amazon, Microsoft, and a dense cluster of well-compensated tech workers. Its zero state income tax is a genuine and significant advantage — RSU vests, bonuses, and salary are taxed only by the federal government, not the state. A senior Amazon engineer vesting $300K of stock in Washington owes nothing to Olympia on that income.

But the zero-income-tax story isn't quite complete anymore. Since 2022, Washington has levied a capital gains excise tax on long-term gains above an annual standard deduction. The rate is 7% (and 9.9% for gains above $1 million, under a tiered structure added in 2025). For tech employees with meaningful appreciated stock, this matters — and it's widely misunderstood.

This guide covers how Washington taxes equity compensation specifically, what's exempt, how the rules compare to California's, and how to plan around the capital gains excise tax.

Washington's tax structure for tech employees

RSUs in Washington: two separate tax events

At vest: no Washington tax

When RSUs vest, the fair market value at vest is ordinary income — taxed by the federal government at your marginal rate (22–37% depending on total income), plus FICA. Washington collects nothing on this event. This is the biggest single advantage of being a WA-based tech employee versus one in California, where that same vest income would face 9.3–13.3% CA income tax on top of federal.

After vest: potential capital gains excise tax on appreciation

Your cost basis in the shares is the FMV at vest. If you hold the shares after vesting and later sell them at a gain, the gain is treated as a capital gain — short-term (if you held less than 1 year from vest) or long-term (if you held more than 1 year from vest).

• Short-term gains (held <1 year from vest): Washington's capital gains excise tax applies only to long-term capital gains. Short-term gains are not subject to WA capital gains tax. They are, however, subject to federal ordinary income tax rates (up to 37%).
• Long-term gains (held ≥1 year from vest): These are potentially subject to Washington's capital gains excise tax if your total net long-term gains for the year exceed the annual standard deduction ($278,000 for 2025, TBD for 2026). Gains above the deduction are taxed at 7% (or 9.9% for gains above $1M).

Concretely: a senior Microsoft engineer vests $250K of stock in January 2025 (ordinary income, no WA tax). In February 2026 (13 months later), the stock has grown to $310K. They sell and realize a $60K long-term capital gain. Their total LTCG for 2026 is $60K — well below the ~$278K-ish deduction. No Washington capital gains tax owed. Federal LTCG rates apply (0%, 15%, or 20% depending on their total income, plus potential 3.8% NIIT).

The Washington capital gains tax becomes real when gains are large — concentrated single-stock positions, large lots of appreciated employer stock, or multiple vesting events held for years.

ISOs and NSOs in Washington

ISOs

Washington has no state income tax, which dramatically simplifies ISO planning compared to California:

• At exercise: No WA tax event. The ISO spread (FMV minus strike) triggers federal AMT as an ISO preference item, but Washington collects nothing.
• At qualifying disposition: If you meet the 2-year/1-year holding periods, the gain is federal long-term capital gain. For Washington purposes, that same gain is subject to the capital gains excise tax if it exceeds the annual deduction. (Unlike California, which imposes no AMT on ISOs at exercise but taxes the sale at full ordinary income rates regardless of holding period.)
• At disqualifying disposition: The spread becomes ordinary income (no WA tax). Any remaining gain (above the spread) is capital gain.

NSOs

Non-qualified stock options are taxed at exercise: the spread is ordinary income federally, and zero to Washington. Post-exercise appreciation held over one year is LTCG — potentially subject to Washington's capital gains excise tax if your total annual gains exceed the standard deduction.

ESPP in Washington

Employee Stock Purchase Plans (§423 plans) in Washington follow the same basic split:

• Disqualifying disposition (sell within 1 year of purchase or 2 years of offering): ordinary income component = no WA tax; any remaining short-term gain = no WA capital gains tax (short-term gains not covered).
• Qualifying disposition (hold ≥1 year from purchase AND ≥2 years from offering start): the 15% discount plus look-back benefit is ordinary income (no WA tax); post-purchase appreciation is LTCG. The LTCG portion can be subject to WA capital gains excise tax if total annual gains exceed the standard deduction.

See the ESPP guide and ESPP calculator for a full side-by-side comparison of qualifying vs. disqualifying dispositions after tax.

What's exempt from Washington's capital gains excise tax

The California-to-Washington move: what actually changes

Moving from California to Washington is one of the most common tech-worker financial planning moves, often driven primarily by the 13.3% California income tax differential. Here's what actually changes for equity comp:

On ordinary income events (RSU vests, salary, bonus), moving to Washington is an unambiguous win. On large long-term capital gain events, Washington is still meaningfully cheaper than California — but not free. The 7–9.9% capital gains excise tax is real and should be planned around.

Unlike California, Washington does not have long-arm sourcing rules

This is an important distinction. California's equity sourcing rules can claim a portion of RSU vests and option exercises even after you move out of state — proportional to the time you worked in California during the grant-to-vest period. Washington has no analogous rule for its capital gains excise tax.

Washington's capital gains excise tax is based on residency at the time of sale. If you are a Washington resident when you sell stock and realize a long-term gain, you owe WA capital gains excise tax on the net gain above the standard deduction. If you move out of Washington and then sell (after establishing residency elsewhere), you generally do not owe Washington capital gains excise tax on that sale.

This matters for large single-stock positions or IPO lock-up expiration events: timing residency around the sale event is much more tractable in Washington than in California. (Note: California may still assert a sourcing claim on the gain if the stock was granted while you were a CA resident — a separate and parallel issue for former CA workers who moved to WA.)

Planning strategies for Washington tech employees

1. Donate appreciated stock to a DAF instead of selling

If you contribute highly appreciated stock directly to a donor-advised fund (DAF), you avoid the capital gains realization event entirely — no federal LTCG tax, no Washington capital gains excise tax. You get a charitable deduction for the full fair market value. For tech employees with significant concentrated stock and any charitable giving intent, this is almost always better than selling and donating cash.

2. Spread large sales across calendar years

The $278K standard deduction (2025) resets each calendar year, per individual. If you have $600K in long-term gains to realize, splitting the sales across two tax years ($300K each) may keep you below or near the threshold each year rather than paying 7% on $322K in a single year. Use a 10b5-1 plan to automate structured selling during open windows.

3. Harvest losses to offset gains

Washington's capital gains excise tax is applied to net long-term capital gains — gains minus losses. Intentional tax-loss harvesting (selling depreciated positions to realize losses) reduces your net gain, potentially keeping you under the standard deduction. See the concentrated stock guide for detailed mechanics.

4. Maximize retirement account contributions

Gains inside 401(k)s, IRAs, and Roth IRAs are entirely exempt from Washington's capital gains excise tax. Maxing retirement accounts — including the Mega Backdoor Roth if your plan supports it — routes more capital appreciation through an exempt vehicle. The Mega Backdoor Roth calculator shows your exact contribution space.

5. Time residency for large liquidity events

If you have a large unrealized gain event on the horizon (IPO lock-up expiration, large option exercise, pending acquisition), and you're already planning a move out of Washington, timing the residency change before the sale can eliminate the WA capital gains excise tax on that event. Unlike California, Washington's tax doesn't follow you after you move.

What a fee-only advisor can help you model

• Year-by-year RSU vest and sale plan optimized to minimize combined federal + WA capital gains tax
• Whether a DAF strategy makes sense given your charitable intent and stock concentration
• The exact WA capital gains excise tax on planned sales, and how to sequence across tax years
• If you moved from California, whether CA sourcing rules still apply to existing equity grants
• ISO exercise timing in Washington vs. the AMT exposure, now that WA doesn't add a second layer of complexity like California does