Does Harvesting Capital Gains at 0% Save You Anything?

How the Trick Works

Capital gains stack on top of your other income. Say a couple has $60,000 of taxable income from other sources. They have $38,900 of room before the 0% bracket ends. They can sell shares carrying $38,900 of gain and owe no federal tax.

The wash sale rule blocks a loss when you buy back within 30 days. It does not apply to gains. So the couple buys the shares back immediately. They own the same investment, with a higher basis, and a future sale will show a smaller gain.

The benefit depends on one question. Will you ever pay federal tax on those gains if you do nothing?

Ray and Nadia, Where It Helped a Little

Ray is 62 and Nadia is 61. They live in Texas, which has no state income tax. They hold $800,000 in a brokerage account with about $500,000 of gain. They have $1.55 million in traditional 401k accounts and $60,000 in a Roth IRA. They spend $150,000 a year in today’s dollars and wait until 67 for Social Security. Each year the plan converts enough to fill the 10% bracket.

The engine harvests about $40,000 of gain in each of 2026, 2027, 2028 and 2029. The total is $158,757, all at 0%. Then it stops. Over the 34-year plan, their lifetime tax drops from $570,750 to $566,865. That is $3,886.

Here is where the money comes from. Their plan spends from the brokerage account first, so they sell it down in the early years. In 2030 they sell what remains, and their MAGI jumps to $165,390. Without harvesting they owe $2,563 of federal capital gains tax that year. Four years of harvesting shrink the 2030 gain until the tax disappears. The other $1,323 of the saving comes from lower ordinary income tax in later years.

The engine stops harvesting after 2029 on purpose. It checks whether any later year still owes federal tax on brokerage gains. After 2030 none does, so more harvesting would cost effort and save nothing.

Owen and Priya, Where It Saved Nothing

Owen is 64 and Priya is 63, also in Texas. They hold $500,000 in a brokerage account with about $250,000 of gain and $2.3 million in Roth IRAs. They spend $70,000 a year and wait until 70 for Social Security. They run no conversions.

Their income stays low enough that they never owe federal tax on a gain. They pay $0 of federal capital gains tax whether they harvest or not, and the engine recommends $0 of harvesting. Their lifetime tax is $0 both ways.

Plenty of retirees look like Owen and Priya. They spend from the brokerage account first, so they sell the shares in the low-income years at 0% without trying. Harvesting rearranges the timing of a sale that was already free.

What Makes It Pay More

Harvesting pays when the brokerage account outlasts the low-income years. We changed Ray and Nadia to hold $2.4 million with $1.5 million of gain. The engine harvested $753,034 across 14 years, and the lifetime tax saving rose to $8,053. A bigger account means more gain waiting for the years when Social Security and required distributions push income into the taxed brackets.

Even that case saves a few thousand dollars spread over three decades. If your situation looks like Ray and Nadia’s or bigger, the move is worth doing once the numbers confirm it. It rarely changes whether a plan works.

Three Costs the 0% Rate Hides

A realized gain counts in your MAGI even when the federal rate is 0%. That income can push a couple over the ACA 400% line. It can raise a Medicare surcharge two years later. It can make more of your Social Security taxable. We cover those lines in Retirement Income Has Cliffs.

Most states tax the gain at ordinary rates. A 0% federal rate can still bring a state bill, which is why both couples here live in Texas.

Roth conversions compete for the same room. The 0% ceiling sits close to the top of the 12% bracket, so a large conversion can use up the harvest room in the same year. Ray and Nadia convert only to the top of the 10% bracket for this reason. We compare the order of withdrawals in brokerage first or IRA first.

A Test You Can Run Yourself

Ask when your brokerage account runs out. If you spend it before Social Security, a pension or required distributions lift your income, it runs out inside the 0% years and harvesting adds nothing. If it will still hold large gains when your income rises, the later tax will reach those gains, and harvesting now can remove some of it.

ThunderHarbor runs this test for you. It builds a projection without harvesting, checks whether any later year pays federal tax on brokerage gains, and recommends an amount only when one does.