US Tax Tools

Equity Compensation

How RSUs, ISOs, NSOs, ESPPs, and 83(b) elections are taxed — vesting, the AMT trap, qualifying vs disqualifying dispositions, double-trigger pre-IPO grants, QSBS planning, and multi-state allocation for movers.

11 articles

State Tax

RSU Multi-State Allocation Explained: Workday Fraction Method

How RSU vest income is allocated across US states when you change state between grant and vest. Workday-fraction method, IRS guidance, CA + NY + 14-state grid.

rsu multi-state equity
State Tax

RSU Trailing State Tax Explained: CA + NY After You Move

When you sell RSUs after moving states, your former state may still claim the W-2 portion. Learn CA FTB Pub 1004 + NY 14-day rule + Form 540NR / IT-203 filing.

rsu trailing-state multi-state
Investment

83(b) Election Deadline 2026: 30 Calendar Days, No Extensions

Section 83(b) election must be postmarked within 30 days of grant — the Tax Court has rejected every late-filing excuse. Step-by-step filing guide for 2026.

83b stock-options equity
Investment

Double-Trigger RSUs Explained: Pre-IPO Tax, IPO Day, and the 22% Trap

Most private tech companies grant double-trigger RSUs that defer income recognition until both time vest AND a liquidity event. The structure protects employees from owing tax on illiquid stock — but creates a multi-million-dollar single-day income event at IPO with a punishing supplemental-withholding gap.

rsu pre-ipo double-trigger
Investment

ESPP Qualifying vs Disqualifying Disposition: Lesser-of Rule, FICA Exemption, and the Lookback

§423 Employee Stock Purchase Plans use a 'lesser-of' rule on qualifying dispositions that trips up most tax software defaults. Plus the FICA exemption that survives both qualifying AND disqualifying treatment, and how the 15% lookback discount produces ordinary-income recognition that exceeds the actual gain.

espp stock-compensation equity
Investment

The $100,000 ISO Limit Explained: When ISOs Auto-Convert to NSOs

IRC §422(d) caps the aggregate fair market value of stock that can become first-exercisable in any one calendar year as ISO at $100,000 per employee. Anything above is automatically reclassified as NSO regardless of grant agreement. How to detect when you trip the cap and what changes when you do.

iso nso stock-options
Investment

QSBS Exemption Guide: How Section 1202 Excludes Up to 100% of Founder Gain

Qualified Small Business Stock under IRC §1202 lets eligible founders and early employees exclude federal capital gains tax — up to the greater of $10 million or 10× basis per issuer — when selling C-corp stock held five years. The qualification tests, the 5-year hold, the $50M aggregate-asset cap, and which states refuse to conform.

qsbs section-1202 founder-tax
Investment

RSU 1099-B Cost Basis Correction: Form 8949 Code B Walkthrough

Brokerages routinely report $0 cost basis on Form 1099-B for RSU and ESPP sales — even though you already paid ordinary income tax on the vest-day FMV. Without a basis correction on Form 8949, you pay tax twice on the same dollars. Step-by-step on the code B adjustment.

rsu espp stock-compensation
Investment

RSU Sell-to-Cover Explained: How Many Shares Disappear at Vest

Sell-to-cover withholds shares at vest to pay federal tax (typically 22% supplemental), Social Security, Medicare, and state. Why your net-share count is always less than you expected, the supplemental withholding gap, and when same-day-sale or cash withholding is the better choice.

rsu stock-compensation equity
Investment

RSU Tax Guide: How Restricted Stock Units Are Taxed at Vesting and Sale

Restricted stock units are taxed twice — once as ordinary income at vest, again as capital gains at sale. A complete guide to withholding, double-taxation traps, and the tax-smart way to manage your RSU grant.

rsu stock-compensation equity
Planning

Alternative Minimum Tax (AMT) Explained: Who Pays It in 2025

Understand how the Alternative Minimum Tax works, the 2025 AMT exemption amounts, income triggers, and strategies to avoid or minimize AMT liability.

amt alternative-minimum-tax tax-planning

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Last updated June 25, 2026 Tax year 2025-26

Data sources: IRS (irs.gov), Social Security Administration

This tool is general information only, not financial advice.

Reviewed by USTax Tools Editorial Desk

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