Capital Gains Timing and Tax-Loss Harvesting Strategy

Portfolio tax efficiency depends on holding period qualification, wash sale rules, and cost basis selection that require coordinated tracking across accounts to optimize outcome.

Holding period determines your rate. Investments held longer than one year qualify for long-term capital gains rates -- 0%, 15%, or 20% depending on your income. Sell before the one-year mark and the gain is taxed as ordinary income, which can be nearly double the rate. This single distinction drives most tax-aware investment timing decisions.

The wash sale rule blocks easy tax harvesting. If you sell a position at a loss and repurchase a "substantially identical" security within 30 days before or after the sale, the IRS disallows the loss. The disallowed loss gets added to the cost basis of the replacement shares, deferring but not eliminating the benefit. This 61-day window (30 days on each side) catches more people than they expect.

Cost basis method matters at sale time. You can use specific identification to choose which shares to sell, potentially selecting high-cost-basis lots to minimize gains. But the election must happen at the time of sale, not after. Mutual funds present an additional wrinkle: they distribute embedded capital gains annually to all shareholders, even if you never sold a share.

The tradeoff: Tax-efficient investing requires tracking at the individual lot level and coordinating across accounts. The savings are real but demand year-round attention, not just a tax-season review.