Offsetting RSU Gains Before Year-End Without Tripping the Wash-Sale Rule

Harvesting a loss means selling a down position before December 31, 2026 to offset the capital gain you realize trimming a concentrated RSU stake. That December 31 line is the tax-year cutoff for realizing losses. But rebuy the same stock inside 30 days and the wash-sale rule disallows the loss.

Where the December 31 deadline actually comes from

A realized loss counts for 2026 only if the trade happens inside the 2026 tax year, which for a calendar-year filer closes December 31. That is the whole deadline. No special harvesting season, just the ordinary year-end cutoff for what lands on your Schedule D.

Keep in mind the trade date, not the settlement date, is what puts a stock loss in the 2026 column. If your broker dates it differently, confirm that with your tax preparer before the last week of December.

The gain is what holds you back, not the logic

Take a composite tech employee sitting on about $600,000 of appreciated RSUs, roughly 30% of her assets. She wants to redeploy and she already knows the concentration is the risk. What stops her is the capital gains tax on selling, not the diversification math. That is the same concentration trap a lot of San Diego equity-comp earners sit in, and it is worth reading through the hold-or-fold decision first.

Harvesting losses elsewhere in the portfolio is one lever that offsets part of the gain from trimming a position like that. One, it can soak up realized gains dollar for dollar. Two, it can knock up to a set amount off ordinary income. But it is a partial offset on a six-figure gain, not a solution to it.

The tax on the trim is heavier in California than people expect. California does not give capital gains a lower rate, so the state taxes the gain as ordinary income (CA FTB, 2025). On the federal side, a 3.8% net investment income tax applies above $200,000 single or $250,000 married filing jointly in MAGI (IRS Topic No. 559, 2025), and the top brackets run 35% over $256,225 and 37% over $640,600 for a single filer in 2026 (IRS Rev. Proc. 2025-32). Stack those and the trim can hit you hard in taxes.

If the whole problem is the embedded gain, harvesting is not the only lever. Donating the appreciated shares moves the gain off your return entirely, which is a different tradeoff worth pricing against a sale.

The wash-sale rule, and the 30-day window on both sides

As IRS Publication 550, Investment Income and Expenses defines it, a wash sale happens when you sell a stock or security at a loss and buy a substantially identical one within 30 days before or after the sale. Buy that replacement inside the window and the loss is disallowed.

Read “before or after” literally. It is 30 days on each side, a 61-day window centered on the sale. The disallowed loss is not erased, it gets added to the basis of the replacement shares, so you recover it later when you sell those.

Here is the part that catches equity-comp earners specifically. A scheduled RSU vest, an automatic ESPP purchase, or a dividend reinvestment that lands inside that 61-day window can be the purchase that disallows the loss, even though you never placed the trade. The rule also reaches buys in your IRA and, in practice, a spouse’s accounts. So before you harvest, you need your vest and ESPP calendar in front of you.

Short-term versus long-term losses change the value

A loss is not just a loss. Short-term losses offset short-term gains first, and those short-term gains are the ones taxed at your full ordinary rate, so a short-term harvested loss tends to shield the most expensive gain (IRS Instructions for Schedule D, 2025).

What harvesting does not do

It does not make the loss free money. It defers tax, it does not cancel it, and when you buy a replacement the lower basis means a larger gain down the road.

Against ordinary income the offset is capped. If your net capital loss runs past the limit, you “can carry the loss forward to later years,” per IRS Topic No. 409, at up to $3,000 a year ($1,500 married filing separately). On a concentrated position, the harvest is a chip off the gain, not a reset.

A sequence that keeps the loss intact

First, list your lots and their acquisition dates so you know which are short-term and which are long-term.

Second, map every scheduled vest, ESPP purchase, and dividend reinvestment in the 61-day window around the planned sale date.

Third, pick a replacement that keeps you invested without being substantially identical, a broad sector or index fund rather than the same stock, if you do not want to sit in cash for a month.

Fourth, check wash-sale exposure across every account, including your IRA and a spouse’s, before you place the sale. This is the check to run before the step you cannot undo.

Fifth, then sell.

Which of your vests land in December? If you can answer that in one line, you can usually tell within a minute whether a clean harvest is even available this year. Happy to walk your actual lots with you during a complimentary review. Just let me know. Hope that helps.

Does the wash-sale rule apply if I rebuy the shares in my IRA?

Yes. [IRS Publication 550](https://www.irs.gov/publications/p550) treats a purchase of substantially identical stock for your IRA or Roth IRA inside the window as a wash sale, and under [Rev. Rul. 2008-5](https://www.irs.gov/pub/irs-drop/rr-08-05.pdf) the IRA’s basis is not increased by the disallowed loss, so it is lost for good. That makes an IRA buy worse than a taxable one. Confirm your IRA contribution and reinvestment timing before you harvest.

Can I harvest a loss and still stay invested?

Yes. Two clean paths. One, buy something that is not substantially identical during the 30 days, such as a broad index or sector fund in place of the single stock. Two, wait the full 31 days and rebuy the same security. The first keeps you in the market, the second keeps the exact position, and only one costs you time out.

What if my losses are bigger than my gains this year?

You net the excess against ordinary income up to $3,000 ($1,500 if married filing separately) and carry the rest forward to future years, per IRS Topic No. 409 (2025). The carryforward does not expire, so a large harvested loss can keep working against gains for several years.

Does California change the harvesting math?

California taxes capital gains as ordinary income with no preferential rate (CA FTB, 2025). The federal loss netting still flows onto your state return, but there is no lower state rate on the gain for a loss to protect, so the state portion of the trim is a straight ordinary-income hit.