10b5-1 Plans for Tech Executives: SEC Rules and Tax Planning

A Bay Area executive who lets a 10b5-1 plan sell ISO shares one day before the §422 holding-period clock finishes can hand $300,000+ to the IRS on a single tranche, with no legal way to unwind the trade. If you are a VP, SVP, or C-suite officer at a public San Jose, Palo Alto, or Mountain View tech company, most of your wealth probably sits in one stock ticker and most of the calendar is closed to you. Quarterly earnings blackouts, M&A blackouts, and the constant drip of material non-public information mean you cannot just call your broker and sell when you want liquidity. The legal mechanism that solves this is a Rule 10b5-1 trading plan: a prearranged, written schedule of sales that gives you an affirmative defense against insider-trading allegations and lets your broker execute trades on autopilot, even on days you would otherwise be locked out.

The trade-off: once the plan is in effect, you have surrendered discretion over when shares get sold. That is fine for the SEC. It can be expensive for taxes if the plan was written without coordinating with your RSU vest cadence, your ISO holding-period clocks, or your concentrated-stock diversification goals. The plan is a one-way ratchet. You cannot unwind a sale because the price moved against you, and you cannot pause it because your CPA finally noticed an AMT trap.

This guide covers how Rule 10b5-1 works, what the 2023 SEC amendments changed, and the tax interactions a Bay Area executive should model with their CPA before signing the plan. We work through these scenarios constantly with our equity compensation team at Silicon Valley Tax.

What a 10b5-1 Plan Is

Rule 10b5-1, adopted by the SEC in 2000, provides an affirmative defense to insider-trading liability under Rule 10b-5 of the Securities Exchange Act of 1934. The defense applies to any sales (or purchases) executed under a written plan that was adopted in good faith, at a time when the insider was not aware of material non-public information, and that specifies the amount, price, and date of each trade (or an objective formula for determining those).

Who needs one in practice:

• Section 16 officers and directors of public companies, who are subject to Section 16 reporting on Forms 3, 4, and 5
• 10% beneficial holders of any class of registered equity
• Other insiders with regular access to MNPI: principal accounting officers, general counsel, segment heads, and anyone on the company's restricted trading list

A plan can authorize sales of already-owned shares, sales tied to future RSU vests, exercise-and-sell or exercise-and-hold transactions on options, and combinations of all three. Modern plans frequently include conditional triggers (sell N shares if price hits X, otherwise sell M shares at end of quarter) and price-collar logic.

The SEC's own summary of the rule lives at the December 2022 press release announcing the amendments, and the full rule sits in 17 CFR 240.10b5-1.

The 2023 SEC Amendments

The SEC overhauled Rule 10b5-1 effective February 27, 2023, after a decade of complaints that the original rule was being abused by insiders who adopted plans, then either modified them or scheduled the first trade for a few days later when they happened to know what was coming. The key changes:

1. Cooling-off period. For officers and directors, the first trade under a new (or modified) plan cannot occur until the later of 90 days after adoption or two business days after the next periodic financial disclosure (capped at 120 days). For other insiders who are not officers or directors, the cooling-off is 30 days. Issuer plans (where the company itself trades) get no cooling-off period under the rule, but most companies impose one anyway.
2. Single-plan-per-12-months restriction. An insider may only have one active 10b5-1 plan for open-market trades at any given time, and may only adopt one single-trade plan within any rolling 12-month period. Exceptions exist for sell-to-cover plans tied to tax withholding on RSU vests, and for overlapping plans where the later plan does not start trading until the earlier one ends.
3. Good-faith requirement, written. The amended rule makes explicit that the insider must adopt and operate the plan in good faith and continue to act in good faith throughout the life of the plan. Officers and directors must include a written certification that, at adoption, they are not aware of MNPI and are adopting the plan in good faith.
4. Form 4 disclosure of 10b5-1 transactions. Trades executed under a 10b5-1 plan must be flagged on the Form 4 with a checkbox, and the plan adoption itself must be disclosed in the issuer's quarterly 10-Q or 10-K.
5. Quarterly issuer disclosure. Issuers must disclose in 10-Qs and 10-Ks the adoption, modification, or termination of any Rule 10b5-1 (or non-Rule 10b5-1) trading arrangement by directors and Section 16 officers, including the material terms.

The practical implication: the 90-day cooling-off period eliminates the old playbook of adopting a plan a week before announcing bad news and selling into the market days later. It also means an executive planning a year-end liquidation needs to put the plan in place by early October at the latest.

Why This Matters for Tax Planning

The most important thing to understand: the tax event happens when the sale executes, not when you adopt the plan. You owe capital gains tax on the year of the trade based on that day's price minus your basis. The IRS does not care that you set the plan up months earlier or that you cannot legally cancel.

That sounds obvious, but it has three consequences that catch executives off guard:

• You cannot tax-loss-harvest reactively. If the stock drops 40% three months into your plan, you cannot pause the plan to wait for a recovery, and you cannot accelerate sales to harvest losses without amending (which restarts the cooling-off period and creates evidentiary problems, discussed below).
• You cannot choose the tax year of the gain. If your plan calls for monthly sales and December is a big tax year for you for other reasons (a vested RSU tranche, a private secondary), you cannot pull the December sale into January. The plan owns the calendar.
• You cannot delay short-term-to-long-term. If your plan inadvertently sells shares that crossed the one-year holding-period line three days from now, you eat the short-term rate. The plan must be designed to honor your holding-period boundaries on the front end.

Bay Area executives in the 37% federal bracket also owe the 3.8% NIIT, up to 13.3% California (or 14.4% with the mental-health surcharge), and the 0.9% Additional Medicare. A short-term sale that should have been long-term costs roughly 17 percentage points on the gain. On a $1M position, that is $170,000 lost to bad calendar design.

Coordinating With RSU Vests

If your compensation package includes RSUs, your default tax exposure is already preset: on each vest date, the FMV of the shares is wages on your W-2, your employer withholds at supplemental rates (typically 22% federal on the first $1M of annual supplemental wages; 37% on the excess above $1M per IRC §3402(g)), and you keep whatever shares the broker did not sell to cover. The standard 22% supplemental withholding leaves most VP-and-above executives underwithheld by 10-15 percentage points until the $1M tier kicks in.

A well-designed 10b5-1 plan addresses both:

• Sell-to-cover plus top-up withholding. The plan instructs the broker to sell enough additional shares on each vest to cover the gap between the 22% default and your actual marginal rate (federal plus state plus NIIT plus Medicare). The extra cash gets remitted to the IRS via estimated payments or supplemental W-2 withholding adjustments.
• Quarterly diversification windows. Rather than letting the post-vest shares accumulate into a concentrated position, the plan schedules a recurring sale of N shares (or N% of vested shares) each quarter. This forces diversification on autopilot, regardless of how you feel about the stock that week.

For deeper background on the RSU side, see our RSU vesting guide and the California RSU tax planning page.

Coordinating With ISO Exercises and the §422 Clocks

Incentive stock options have two holding-period clocks under IRC §422 that determine whether the disposition is qualifying (preferential long-term capital gains treatment on the spread between strike and sale price) or disqualifying (ordinary income on the spread between strike and FMV at exercise):

• 2 years from grant date
• 1 year from exercise date

For a 10b5-1 plan that includes ISO exercises, the schedule needs to be designed so that the corresponding sale dates fall after both clocks expire. Selling one day too early triggers a disqualifying disposition: the exercise-date spread (FMV at exercise minus strike) becomes ordinary income at your top marginal rate; post-exercise appreciation stays capital. On 50,000 shares with a $30 exercise-date spread and the executive in the 37% federal plus 13.3% California bracket (14.4% above $1M), a one-day mistake on the ordinary-income portion costs roughly $300,000 in incremental tax.

Because the 90-day cooling-off period for officers and directors stacks with the 1-year-from-exercise hold, an ISO-heavy 10b5-1 plan typically needs to be drafted 15 months before the first qualifying sale: 90 days cooling-off, then a year of holding before the first share can be sold qualifying. Our ISO vs NSO breakdown walks through the §422 mechanics in more detail, and our AMT 2026 post covers the exercise-year AMT exposure.

The Modification Trap

You can, technically, modify or terminate a 10b5-1 plan. You should almost never do it. Two reasons:

First, any modification that changes the amount, price, or timing of a planned trade restarts the cooling-off period. The modified plan is treated as a brand-new plan for cooling-off purposes. If you change anything in March, the next trade cannot execute until June at the earliest.

Second, and more dangerous: a voluntary modification can be cited by the SEC or a plaintiff's lawyer as evidence that the affirmative defense never applied. The good-faith requirement is ongoing. If you modify the plan after learning bad news (or even after good news, in some interpretations), the modification looks like you were using MNPI to optimize the plan, and the entire defense can collapse. The original sales that occurred under the unmodified plan may still be defensible, but the modified plan and the trades that follow it are exposed.

The defensible categories of modification are narrow: cancellation in connection with the insider's death or termination, cancellation following a corporate transaction that ends the trading window, and ministerial corrections that do not change the substance of the trades. Anything else needs board-level legal sign-off in advance.

The practical takeaway: get the plan right the first time. Build in conditional triggers and price collars at adoption rather than planning to amend later.

Tax-Loss Harvesting Inside a 10b5-1 Plan

You can build tax-loss harvesting logic into the plan at adoption. The plan can specify: sell N shares of stock A if the price is below a threshold (harvesting the loss), and simultaneously buy N shares of a replacement security. The replacement cannot be the same stock or a substantially identical security for 30 days before or after the loss sale, or the loss is disallowed under the wash-sale rule.

The wash-sale rule at IRC §1091 disallows a loss on the sale of a security if you (or your spouse, or an IRA in your name) buy a substantially identical security within the 61-day window centered on the sale date. The disallowed loss is added to the basis of the replacement security and recovers when that replacement is eventually sold.

The wash-sale rule is the single most-violated tax rule we see in executive 10b5-1 plans, and the violation usually comes from account interaction rather than from the plan itself. Common patterns that trigger it:

• The executive's plan sells employer stock at a loss in December; the executive's RSU automatically vests in January and the vest is treated as a purchase for wash-sale purposes
• The executive sells at a loss in their taxable brokerage; their spouse buys the same stock in an IRA that month
• The plan sells one share class (say, common); the company's ESPP buys another class (or a contractual equivalent) within the window

The plan can avoid the first pattern by simply not selling at a loss in months that bracket scheduled RSU vests. The second and third require coordination across accounts that the plan itself cannot see; that is where your CPA earns their fee.

Worked Example: $4M Concentrated Position, 36-Month Diversification

VP of engineering at a public Bay Area tech company. Concentrated position: 40,000 shares at $100, total $4M. Basis: roughly $30 per share from a mix of old ISO exercises (qualifying) and ESPP purchases. She wants to diversify out of the position over three years without picking a price.

The plan, adopted September 2026 with first trade February 2027 (after the 90-day cool-off and Q4 earnings):

• Sell 1,111 shares per month for 36 months (1/36 of the position)
• Limit-price floor of 95% of the prior 20-day VWAP on the trading day; no sale executes below that floor
• Skipped sales roll into the next month, capped at 2,222 shares per execution to prevent market impact
• Quarterly diversification check with the CPA to true-up estimated tax payments

Tax modeling, assuming a flat $100 share price for simplicity:

• Annual sale: 13,332 shares at $100 = $1,333,200 proceeds
• Basis: 13,332 × $30 = $399,960; long-term gain = $933,240 per year
• Federal tax: $933,240 × 20% LTCG = $186,648, plus 3.8% NIIT = $35,463, total federal $222,111
• California tax: $933,240 × 13.3% = $124,121 (California taxes capital gains as ordinary income; note income above $1M hits the 14.4% effective rate including the 1.1% mental health surcharge)
• Total annual tax: roughly $346,232, leaving net of tax $987,000 per year for three years

QBI does not apply here (W-2 wages and capital gains are not qualified business income). The federal AMT exposure is minimal because the ISO spread was already recognized in earlier years; the current sale is straight LTCG. The NIIT applies in full because the executive is comfortably over the $250,000 MAGI threshold for joint filers.

If the same VP had instead sold the entire $4M in a single year, the marginal LTCG rate would still be 20% federal (the top LTCG bracket is reached well below $4M), but California would tax the entire gain in one year at the top 13.3% rate (14.4% effective above $1M with the mental health surcharge), NIIT would still apply, and her estimated-tax compliance burden would spike. The 36-month spread is roughly tax-neutral compared to a single-year liquidation but smooths cash flow and reduces concentration risk.

What Goes Wrong Without a CPA

The most common 10b5-1 mistake we see at intake: the plan's first ISO sale lands inside the §422 qualifying window by a comfortable margin, but a separate sell-to-cover instruction at the broker triggers a wash-sale violation against a loss harvested two weeks earlier in a personal taxable account. The cost ranges from $20,000 on a small loss-harvest pair to $200,000 on a multi-account wash that spans the executive's spouse's IRA. Executives who let general counsel draft the plan alone routinely miss the §422 one-year-from-exercise clock interaction with the 90-day cool-off, which can convert a qualifying disposition to disqualifying ordinary income at top brackets. DIY plan review covers the securities-law side. It does not flag the §1091 wash-sale spouse-IRA exposure, the bunched-RSU-vest withholding gap, or the California 14.4% mental-health surcharge. Those are the items where engagement pays for itself.

Action Items Before You Sign the Plan

• Time the adoption to your earnings calendar. Adopt outside any blackout, and at least 90 days before the first intended trade. December plan adoptions are usually too late for first-quarter sales.
• Map your ISO holding-period clocks. List every ISO tranche, its grant date, exercise date, and the resulting §422 qualifying-disposition window. The plan's first ISO sale should fall safely inside that window.
• Coordinate with the RSU calendar. Build sell-to-cover plus top-up withholding into the plan rather than treating it as a separate sell-to-cover instruction at the broker.
• Check the wash-sale exposure across all accounts. Yours, your spouse's, your IRAs, your kids' UGMAs if you fund them, and any DAF that holds the same stock.
• Pre-commit your charitable plan. If you intend to give appreciated stock to a DAF or directly to a 501(c)(3), exclude those shares from the 10b5-1 plan. Gifted shares cannot be sold under the plan because they will not be in the brokerage account when the trade tries to execute.
• Get legal and tax review on the same draft. Securities counsel writes the plan for SEC compliance. Your CPA models the tax outcomes. They need to see the same draft, and they rarely do unless you force the meeting.

When to Talk to Us

10b5-1 plans sit at the intersection of securities law, executive compensation, and individual tax planning. The securities-law side is what your general counsel and personal attorney handle. The tax side is what we do. We work with Bay Area executives at public tech companies on plan design, ISO and RSU coordination, wash-sale defense, and the year-by-year quarterly estimated tax planning that the plan triggers.

If you are a Section 16 officer, a director, or any insider preparing to adopt or refresh a 10b5-1 plan, the right time to bring in a tax advisor is before the plan is signed, not after the first trade has cleared. Once the plan is operative, the optimization windows mostly close. For broader context, see our post-IPO tax strategy page and the Bay Area tech employee tax overview.

Schedule a free consultation and we will walk through your equity grant schedule, your existing plan if you have one, and the tax modeling that should drive the next plan you adopt.