Sandra is a 58-year-old school administrator named Sandra who has been sitting on $340,000 in unrealized gains across three index funds for the past eleven years. She is not rich by Wall Street standards. She is not a hedge fund manager. And under legislation currently moving through Congress, she could owe tens of thousands of dollars more in federal taxes than she planned for. She did not see it coming. Most people in her position do not.

Here is the number that matters: according to a 2024 Tax Policy Center analysis, proposed capital gains rate increases under current Congressional discussions could affect an estimated 1 in 4 American households with taxable investment accounts, not just the top 1%. The legislation targets earners above $1 million in combined income, but when you stack salary, Social Security, required minimum distributions, and investment gains together, that threshold is closer than most middle-class investors think.

That is not a scare tactic. That is how tax stacking works. Full stop.

What Is Actually on the Table

Let me be direct about this. There are two serious proposals circulating in Congress right now that could reshape how investment profits are taxed.

The first involves raising the top long-term capital gains rate from its current 20% to 28% for households earning above $1 million in combined income annually. The second, more aggressive proposal would tax capital gains as ordinary income at the same rate as wages for high earners, potentially pushing the effective rate above 37% when state taxes are added in high-tax states like California or New York.

Do the math. On a $200,000 capital gain, the difference between a 20% rate and a 28% rate is $16,000. That is a car payment for three years. Gone.

Neither proposal has passed as of this writing. But both have cleared committee discussions, and the budget reconciliation window open this year makes legislative movement more likely than in a typical session. The Joint Committee on Taxation scored the 28% rate proposal as generating approximately $190 billion in additional federal revenue over ten years, which gives it real political staying power.

Here Is What the Other Side Gets Right

Most financial media buries this, but the case for leaving rates alone is not frivolous.

The Tax Foundation’s 2023 modeling found that raising the capital gains rate to 28% could reduce long-term GDP growth by approximately 0.1% annually. That sounds small. It is not small over a decade. The same study found that behavioral responses to higher rates, specifically investors choosing to hold assets rather than sell, could reduce actual revenue collected by as much as 40% compared to static projections. Think about that: Congress might raise rates and collect less money.

There is also the inflation argument. Many of the gains being taxed are not real wealth creation. They are the mathematical result of inflation eroding dollar value over years. A stock purchased for $50,000 in 2010 and sold today for $180,000 looks like a $130,000 gain. In 2010 dollars, the real gain is significantly smaller. The current tax code makes no adjustment for this. That is not a philosophical point. That is the actual tax code.

The argument for rate stability deserves to be heard. It just does not change what you need to do right now.

The Common Mistake Investors Are Making Right Now

Are you making decisions based on what Congress might do, or what you can actually control?

Most investors fall into one of two traps when legislation like this surfaces. The first trap is paralysis: they wait for a bill to pass before adjusting anything, which means they are always one Senate vote behind. The second trap is panic selling: they liquidate positions prematurely, triggering taxable events they did not need to trigger, often in years when their income is already elevated.

Sandra ran the numbers. With $340,000 in unrealized gains spread across three index funds and a projected income of $87,000 this year from salary and a small pension, she is sitting comfortably in the 15% long-term capital gains bracket, which applies to single filers earning between $47,026 and $518,900 in 2025. She is not near the $1 million threshold. But her plan to convert a significant IRA balance to a Roth next year, plus a part-time consulting income she is considering picking up, could push her combined income high enough to trigger the 20% rate on any gains she realizes in that same year. She did not know those income sources stack. Now she does.

Warning: Capital gains do not sit in a vacuum. They get added on top of your ordinary income for bracket calculation purposes. A retiree with $60,000 in Social Security, $40,000 in RMDs, and $80,000 in realized capital gains has a combined income of $180,000 for tax purposes, regardless of how those dollars feel different in daily life.

That is not a minor technicality. That is a $20,000 swing in what you owe.

The Bracket Math Nobody Shows You

When did you last calculate your actual effective capital gains rate for this year, not last year’s numbers?

Here are the 2025 long-term capital gains thresholds for single filers, per IRS Publication 550 guidance applied to current income brackets: 0% up to $47,025 in taxable income; 15% from $47,026 to $518,900; 20% above $518,900. For married filing jointly, the 20% threshold begins at $583,751.

The Net Investment Income Tax adds another 3.8% on top of those rates for single filers above $200,000 and joint filers above $250,000 in modified adjusted gross income. That brings the real top federal rate to 23.8% currently, before any proposed increase.

Did You Know: The 3.8% Net Investment Income Tax was introduced in 2013 as part of the Affordable Care Act. It has never been indexed for inflation, which means the $200,000 threshold that seemed targeted at the wealthy in 2013 now captures a significantly larger portion of the middle class than originally intended.

What the Proposed Rate Increase Means in Real Dollars

Take Sandra’s $340,000 in unrealized gains. If she harvests $60,000 this year while her income is predictable and lower, she pays 15%, a tax bill of $9,000. If she waits two years, adds that consulting income, completes the Roth conversion, and a rate increase passes in the interim, the same $60,000 gain could be taxed at 28%, a bill of $16,800. The difference is $7,800 on a single decision made with adequate information.

How much of your net worth is sitting in a taxable brokerage account right now, and do you actually know what a rate change would cost you at current prices?

Pro Tip: Run a bracket projection before year-end using your actual 2025 income sources. Stack every dollar: wages, dividends, rental income, Social Security at its taxable percentage, RMDs, and any planned conversions. Find your landing zone on the capital gains brackets before you decide whether to realize gains this year or defer them. The IRS withholding calculator does not do this stacking automatically. You have to do it manually or with a CPA who runs scenario-based projections, not just last year’s return.

Your Next 3 Steps

Step 1: Pull every taxable brokerage account statement you have and list every position carrying an unrealized gain above $10,000. Note the purchase date. Anything held under 12 months is a short-term gain taxed as ordinary income, and those positions are your most urgent evaluation priority regardless of any legislative changes. Then calculate your projected 2025 combined income from all sources, including Social Security at its taxable inclusion percentage, RMDs, rental income, wages, and side income. Use IRS Publication 550 thresholds to identify exactly which bracket you land in before stacking any realized gains on top.

Step 2: For your three largest unrealized long-term gain positions, model two scenarios side by side. Scenario A: you harvest a portion of the gain this year at your current rate. Scenario B: you hold through a potential rate increase of 8 percentage points and sell in two years. Calculate the break-even in compounding years. If harvesting now and reinvesting the after-tax proceeds reaches parity with the deferred scenario in under four years, harvesting this year deserves serious weight. Sandra ran this math on her largest fund position and found a 3.1-year break-even. She is harvesting $60,000 before December 31.

Step 3: If your portfolio includes appreciated real estate, inherited securities, or any asset with a stepped-up basis question attached to it, schedule a basis analysis with an estate attorney or CPA before any bill passes, not after. Estate attorneys are already booking into Q1 2026. Legislative passage moves faster than appointment availability. One phone call made this month could protect a basis calculation that a passed bill cannot retroactively undo. Do not wait for a Senate vote to make the appointment.

I spent 15 years on Wall Street. The investors who came out ahead on every major tax law change shared one trait: they acted on what was knowable before the bill passed, not after. The legislation is uncertain. Your income projection, your cost basis, and your bracket math are not. Work with what you can control.