Diversifying a concentrated stock position is what Modera Wealth Management does when one employer's shares dominate your net worth, through a staged sale schedule, a tax bill estimate and an account map. Waiting usually costs more than the tax. A hypothetical 40 percent drop on $900,000 of one stock erases $360,000, more than seven times the $49,500 tax bill of a three-year sell-down.
The deadline that pushes most people here is the next open trading window. Your company's insider trading policy lets you sell only when a window is open, usually a few weeks after each quarterly earnings report. If the window closes with nothing sold, you wait another quarter while new RSUs vest and add shares to the pile. Miss a few of those and the position is bigger than when you started, even though you meant to cut it.
This page isn't for you if most of your shares are still unvested, or if you need the money within two years for a home. That's a cash question, and we say so in the last section. Before reading on, have your stock plan portal open, plus your latest pay stub, so you can check the numbers against your own.
Does a concentrated stock position need a sale schedule 10 to 15 years from retirement?
Yes, once one ticker is a large share of what you own and you plan to stop working in 10 to 15 years. A drop at that stage has fewer years to recover, and each year spent waiting for a rebound is a year the money isn't growing in a spread-out portfolio.
In practice the service is three dated things: a target for the employer stock (a fifth of net worth, for example), a sale schedule tied to each quarterly trading window, and a map of which account every freed-up dollar lands in. Asset location starts on day one. Sale cash can cover living costs so more salary goes into the 401(k), and at 50 the $8,000 catch-up (at 60 to 63, the $11,250 catch-up) widens that room.
The table compares three real choices. Selling everything now has the biggest tax bill and the least risk left; the other two trade tax for exposure.
Three ways to get there
Count the next 12 months of vests in your target. If they add more shares than your schedule sells, the position is still growing and the sale amount per window has to go up.
| Choice | Tax bill | Exposure to a drop | Effort and lock-ups |
|---|---|---|---|
| Sell everything now | One large gain; maybe 20 percent plus 3.8 percent | None after the sale | One trade |
| Sell over three years | Gain spread across years | Falls with each sale | One note per window |
| Hold and hedge, or exchange fund | Deferred; fees added | Reduced, not removed | About a seven-year hold |
Three other decisions move every time shares are sold
Each sale changes your quarterly estimated tax payments, due around April 15, June 15, September 15 and January 15, so Modera Wealth Management sends the year's projected gains to your CPA each fall. Social Security isn't touched, because capital gains aren't earnings; your record is built from salary up to the $184,500 wage base the SSA sets. For a single renter, the estate side is short but real: a transfer-on-death beneficiary on the brokerage account and a current 401(k) beneficiary form.
What Modera Wealth Management sends in the first four weeks
Before any sale amount is final, our advisors decide which account each freed-up dollar lands in. For us, every sale also moves money between taxable, 401(k) and Roth, and we plan that move first. The deliverables arrive in this order.
The checklist table lists what we pull first. Start with the basis row, since it sets the gain on every sale.
| Item | Why it matters | Where to find it |
|---|---|---|
| Basis for each lot | Sets the gain on every sale | Stock plan lot detail |
| Vest schedule ahead | New shares rebuild the position | Stock plan portal |
| Trading window dates | Sales only when the window opens | Insider trading policy |
| Acquisition date per lot | Over one year means long-term | Vest confirmations |
| Last year's income | Shows bracket and surtax room | Form 1040 |
| 401(k) deferral rate | Room to shelter more salary | Pay stub or benefits portal |
- Weeks one and two: lot-by-lot inventory with date, shares and basis
- Same weeks: one-line snapshot of the stock's share of net worth
- Weeks three and four: the playbook with target share, dollars per window, yearly tax bill
- Same delivery: account map of taxable, 401(k) and any Roth
- Before each window: a note confirming that quarter's sale
- Each January: 1099-B checked against the lot inventory
Is the schedule rerun when a refresh grant lands or the stock moves a third?
Yes. We check the playbook before each quarterly trading window opens, and a refresh grant, a price move of about a third either way, a job offer or layoff, a tender or acquisition announcement, or a planned big purchase such as a first home triggers an extra review. Each review restates the remaining sale amounts and that year's estimated tax bill.
$360,000 at risk against a $49,500 tax bill: the numbers that say start
For illustration: Tuan (hypothetical), 34, is a single staff engineer whose RSUs vest every quarter. He rents and hasn't sold a single share yet. Of his $1.2 million net worth, about $900,000 sits in employer stock, with an assumed total basis of $450,000. To get down to a fifth, he sells $220,000 a year for three years: $660,000 sold, $240,000 kept.
Half of each sale is gain, so $110,000 a year is taxed. At an assumed 15 percent federal long-term rate (state tax and the 3.8 percent surtax left out for simplicity), that's $16,500 a year, or $49,500 in total. He also raises his 401(k) deferral from zero to the $24,500 IRS limit for 2026 and replaces the smaller paycheck with sale cash. That moves $73,500 into a tax-deferred account over three years. If the stock fell 40 percent before he sold, he'd lose $360,000. A diversified portfolio can still drop too, and you can lose part of what you invest after the sale as well as before.
One mistake shows up in the 1099-B. Move shares from the plan administrator to an outside brokerage without lot-level basis, and the RSU shares may show no reported basis. A $220,000 sale with $110,000 of true gain is reported as $220,000 of gain, about $16,500 of overpaid tax at the same assumed rate. Fixing it means pulling vest confirmations and W-2s, correcting Form 8949 and, if the return is filed, sending Form 1040-X.
Thresholds to check today
If you're already in your 50s
In your 50s, the $8,000 catch-up at 50 and the $11,250 catch-up at 60 to 63 make sale-funded deferrals larger. Income at 63 sets Medicare premiums at 65, which rise above the $202.90 standard Part B premium once MAGI passes $109,000 single or $218,000 joint, so the heaviest sales belong before 63.
- One stock above a fifth of net worth
- Stop-work date under 15 years away
- 401(k) deferral below $24,500
- Gains plus salary near $200,000 single or $250,000 joint, where the 3.8 percent net investment income tax starts
Should the first sale happen in your next open trading window?
Usually yes, if the stock is over a fifth of your net worth, new vests add shares faster than you sell, and you've never sold a share. It can wait a quarter if most of the position is still unvested or under a lock-up.
A three-year schedule still leaves unsold shares exposed. A 40 percent drop in the first quarter hits most of the $900,000 before the sales happen. And if you need the money within two years for a home, that's a cash decision, not a diversification one.
For a next step, send the request form with the stock plan's lot statement, the latest Form 1040 and your 401(k) statement. Modera Wealth Management takes on families with $500K or more in investable assets, and our fee is set out in the agreement you sign before any work starts. Once the playbook is delivered, the first sale goes on the next open window and the 401(k) change is filed with payroll that same week, mostly over screen-share calls, wherever you live.
A 40 percent drop on $900,000 costs $360,000; a three-year sell-down costs $49,500 in tax.
What people ask about a concentrated stock position
Can I change the sale schedule after the first trade if my company announces a large refresh grant?
Yes. A refresh grant adds future vests, so the schedule gets rerun before the next window. Modera Wealth Management restates the remaining sale amounts and the year's estimated tax bill. Past sales stay as they are; only the amounts still ahead change, usually upward if new shares outpace what you sell.
My stock plan's year-end statement lists shares by grant; which numbers does the sale schedule actually need?
The schedule needs each vest's date, share count and basis, not just grant totals. Grant-level statements can hide those details, so we pull lot detail from the stock plan portal and match it to vest confirmations. Basis sets the gain on every sale, and the vest date decides long-term or short-term treatment.
By what date do I pay the tax on a gain from a sale in the first trading window of the year?
For a sale in the first quarter, the IRS estimated payment is generally due around April 15. Later sales fall into the June 15, September 15 and January 15 payments. Your CPA sets exact amounts, which is why Modera Wealth Management sends projected gains each fall.
Will selling company shares in my 30s lower my Social Security benefit later?
No. Capital gains aren't earnings, so selling shares doesn't change your Social Security record. The SSA builds your benefit from salary, up to the $184,500 wage base for 2026. Sales can affect your tax bill and, later in life, your Medicare premiums through income, but not the benefit itself.
Where should the sale proceeds go if I already put the full $24,500 into my 401(k)?
Once the 401(k) is maxed at the IRS limit for 2026, proceeds usually go to a taxable account holding a spread-out portfolio, plus any cash you need. If you're eligible, a Roth IRA is the next stop. Which investments sit in which account matters as much as what you buy.
Is an exchange fund or a collar worth considering instead of selling $900,000 of one stock?
Sometimes, but both have costs. Exchange funds defer tax and usually expect about a seven-year hold, with fees added. A collar limits losses and also caps gains, and it's still tied to one company. Modera Wealth Management compares both with a staged sale on tax bill, exposure and effort before you choose.
Read the rules at the source
How Modera Wealth Management can also help
This is general information, not advice for your specific situation. Investing involves risk, including loss of principal. Nothing here replaces guidance from a tax professional or attorney. Talk to a qualified adviser before you act.