The Tax-Loss Harvesting Rules You Need to Know

Tax-loss harvesting rules are simple in concept and operationally demanding in practice. A client sells an investment at a loss, uses that realized loss to offset capital gains, and may deduct a limited amount of excess losses against ordinary income. But the details matter: wash-sale windows, substantially identical securities, tax lots, spouse and IRA transactions, dividend reinvestments, and replacement exposure can turn a helpful planning move into a missed deduction or a compliance headache.

For financial advisors, tax-loss harvesting is not just a year-end tactic. It is a portfolio management workflow that should be coordinated with rebalancing, cash needs, concentrated positions, mutual fund distributions, direct indexing, and CPA communication. The best advisor teams treat the rules as a repeatable process rather than a seasonal scramble.

What tax-loss harvesting does

Tax-loss harvesting applies in taxable investment accounts. When a position is worth less than its cost basis, the client may sell it to realize a capital loss. That loss can then be used to offset realized capital gains elsewhere in the portfolio.

If losses exceed gains, current federal rules generally allow up to $3,000 of net capital losses to offset ordinary income each year, or $1,500 for married taxpayers filing separately. Unused losses can generally be carried forward to future tax years.

The strategy does not make a poor investment good. It converts an existing unrealized loss into a tax asset while preserving the client's intended investment exposure through a carefully chosen replacement.

The wash-sale rule is the central constraint

The most important tax-loss harvesting rule is the wash-sale rule. It generally disallows a loss if the taxpayer sells a security at a loss and buys the same or a substantially identical security within the 61-day window that starts 30 days before the sale and ends 30 days after the sale.

That window includes:

• The 30 days before the sale.
• The sale date itself.
• The 30 days after the sale.

If a wash sale occurs, the loss is generally not currently deductible. In many taxable-account cases, the disallowed loss is added to the basis of the replacement security and the holding period carries over. But if the replacement purchase happens inside an IRA or Roth IRA, the result can be worse because the loss may be effectively lost rather than deferred.

What counts as substantially identical?

The phrase "substantially identical" is one of the hardest parts of the rule. The IRS has not provided a simple universal test for every ETF, mutual fund, option, or direct-indexing substitution.

In practice, advisors often look for replacement securities that preserve general market exposure without replicating the exact same position. Selling one company's stock and buying another company in the same sector may be acceptable in many cases. Selling one S&P 500 index fund and buying another fund tracking the same index is more questionable. Replacing an S&P 500 fund with a broader large-cap or total-market fund may be easier to defend, but advisors should coordinate with tax professionals for client-specific guidance.

The goal is to maintain the client's investment plan without creating a transaction that looks like the client never meaningfully changed economic exposure.

Common wash-sale traps advisors should monitor

Many wash sales happen unintentionally. A good workflow checks the full household, not just the account where the loss is harvested.

Watch for:

• Automatic dividend reinvestment plans buying the same security during the restricted window.
• A spouse's account buying the same or substantially identical security.
• Repurchases inside traditional IRAs, Roth IRAs, or other tax-advantaged accounts.
• Model portfolios that automatically buy back the harvested holding.
• Options, contracts, or other instruments that recreate the same exposure.
• Rebalancing trades that conflict with recently harvested losses.
• Employee stock plans or recurring purchases that trigger acquisition inside the window.

The advisor's notes should show not only that a loss was harvested, but also that the household-level wash-sale risk was reviewed.

Tax lots and basis selection matter

Tax-loss harvesting is more precise when the advisor reviews tax lots. A single holding may include shares purchased at different times and prices. Selling the highest-cost lots can realize a larger loss while preserving other lots.

This is especially important for clients who buy into positions over time, receive shares through compensation, or hold legacy assets. The trade decision should reflect the client's tax picture, investment policy, and risk exposure—not just the aggregate position gain or loss.

Harvesting should work with the investment plan

Taxes should not drive the entire portfolio. J.P. Morgan's ranking guidance makes the point clearly: tax-loss harvesting can help only if it is done properly, and taxes should not be the only factor behind an investment decision.

Advisors should ask:

• Does the replacement security keep the client aligned with the target allocation?
• Will the sale create unintended factor, sector, or duration drift?
• Is the client likely to need cash soon?
• Are there upcoming gains, business sales, real estate transactions, or concentrated stock events to offset?
• Does the client have capital loss carryforwards already?
• Has the CPA confirmed the broader tax plan?

The right harvest is one that improves after-tax outcomes without undermining the portfolio's purpose.

Why direct indexing and SMAs change the workflow

Direct indexing and separately managed accounts can create more harvesting opportunities because clients own individual securities rather than only pooled funds. That can allow advisors or portfolio managers to harvest losses in specific names while maintaining broad index-like exposure.

But more opportunity also means more operational complexity. The team must track wash-sale windows, replacement logic, household accounts, tax budgets, and client restrictions. Without clear controls, a scalable tax strategy can become a manual burden.

A practical advisor checklist

Before placing trades, advisor teams can use a checklist like this:

1. Confirm the account is taxable.
2. Identify the specific tax lots and estimated realized loss.
3. Review realized and expected gains for the year.
4. Check capital loss carryforwards.
5. Select a replacement that is not substantially identical and fits the IPS.
6. Review household accounts, spouse accounts, IRAs, Roth IRAs, DRIPs, and automatic model trades.
7. Document the wash-sale window.
8. Communicate with the client's CPA when material.
9. Schedule a review before the 31-day repurchase date.
10. Update client notes and follow-up tasks.

That workflow is where advisor operations often break down. Verlo helps advisor teams organize the documents, client context, notes, meeting follow-ups, and repeatable review steps that support tax-aware planning. It does not replace tax advice, but it can help teams maintain the process around the advice.

The bottom line for advisors

The core tax-loss harvesting rules are straightforward: realize losses in taxable accounts, use them to offset gains, respect the $3,000 ordinary-income limit for excess losses, and avoid wash sales. The hard part is execution across real households with multiple accounts, automated reinvestments, model trades, and changing client goals.

Advisors who combine tax awareness with disciplined portfolio management can make harvesting more than a year-end tactic. They can turn it into a repeatable, auditable client service.

See how Verlo helps advisor teams reduce manual admin work.