Finvest · Personal Finance Guide
Part III · Grow · Chapter 15 of 29

Chapter 15: Taxes, and how to keep more of what you earn

8 min read · Reviewed against 2026 federal figures · Updated June 10, 2026

One sentence costs Americans real money every year: "I don't want the raise; it'll bump me into a higher bracket." It sounds careful. It's mathematically impossible. Earning one more dollar never costs you money, and understanding why is the start of tax literacy, which, dollar for dollar, may be the highest-paying hour in this guide.

Marginal vs. effective: how brackets really work

Your taxable income is what's left after subtractions: for most people, gross income minus the standard deduction, a flat amount everyone gets ($16,100 single, $32,200 married filing jointly in 2026). A tax bracket is a rate that applies only to the slice of taxable income inside its range, not to all of it. Tax brackets work like a staircase: each step taxes only the dollars standing on that step.

The 2026 federal brackets:

Rate Single (taxable income) Married filing jointly
10% up to $12,400 up to $24,800
12% $12,400 – $50,400 $24,800 – $100,800
22% $50,400 – $105,700 $100,800 – $211,400
24% $105,700 – $201,775 $211,400 – $403,550
32% $201,775 – $256,225 $403,550 – $512,450
35% $256,225 – $640,600 $512,450 – $768,700
37% above $640,600 above $768,700

Your marginal rate is the rate on your next dollar: your top step. Your effective rate is your total tax divided by your income, the average across all steps. The marginal rate decides whether a deduction or extra contribution is worth it; the effective rate tells you what you actually paid. They are never the same number, and mixing them up causes half the bad tax decisions out there.

The marginal rate runs your decisions because a deduction removes dollars from the top of your staircase, so it saves tax at your top rate. If Jamie (below) puts $1,000 into a traditional 401(k), that $1,000 comes off the 22% step: a $220 saving, not 12.2% of anything. The same logic prices every move in this chapter and the next: extra income is taxed at the margin, and dollars you shelter are rescued from the margin.

Jamie earns $90,000. Subtract the $16,100 standard deduction: $73,900 of taxable income. The first $12,400 is taxed at 10% ($1,240). The next $38,000, up to $50,400, at 12% ($4,560). The last $23,500 at 22% ($5,170). Total: $10,970. Jamie's marginal rate is 22%, but the effective rate is 14.8% of taxable income, about 12.2% of the full $90,000. A $5,000 raise would be taxed at 22%, so Jamie keeps $3,900 of it. No raise ever leaves you with less.

The 2026 bracket staircase (single filer) 10% 12% 22% 24% 32% $12.4k $50.4k $105.7k $201.8k $256.2k Jamie: $73,900 taxable Top dollars taxed at 22%, average rate only 14.8% 35% and 37% continue above
Figure 15.1. Each 2026 bracket taxes only the dollars on its own step, which is why your average rate is always below your top rate.

Slide your own income through the visualizer above and watch the marginal and effective rates separate. It makes the staircase visceral in a way no table can.

How your investments are taxed

Three flavors, very different prices:

  • Ordinary income: wages, interest, short-term trading profits. Taxed at the bracket rates above.
  • Long-term capital gains: profit on investments held longer than 12 months. In 2026: 0% up to $49,450 taxable income single ($98,900 joint), 15% up to $545,500 ($613,700), 20% above. High earners add the 3.8% net investment income tax above $200,000 single / $250,000 joint.
  • Qualified dividends, meaning most dividends from US stocks held a while, get the same friendly long-term rates.

At the top, the gap between impatience and patience:

SHORT-TERM · HELD < 12 MONTHS
40.8%

Top federal rate on short-term gains (37% + 3.8% surtax).

LONG-TERM · HELD > 12 MONTHS
23.8%

Top federal rate after 12 months (20% + 3.8%). Patience literally pays.

One more term you'll use forever: cost basis, what you paid for an investment. Buy a fund for $8,000, sell it years later for $13,000, and only the $5,000 above your basis is taxed, and only in the year you sell. No sale, no tax bill, no matter how large the paper gain grows. That single fact powers most of the toolkit below: you control when gains become taxable, and often at what rate, just by choosing when to sell, when to hold, and what to give away.

The toolkit: seven legal ways to keep more

EVERYDAY TOOL

Tax-loss harvesting

Sell a losing investment, and the loss offsets your gains, plus up to $3,000 of ordinary income per year, with the rest carried forward indefinitely. Mind the wash-sale rule: buy the same (or a substantially identical) investment within 30 days before or after, and the loss is disallowed. Replace it with something similar but not identical so you stay invested.

FREE LUNCH, SMALL PORTIONS

Asset location

Put tax-noisy assets (bonds, which pay ordinary-income interest) in tax-deferred accounts, and quiet ones (broad stock index funds) in taxable accounts. Worth real money over decades, but it's seasoning, not the meal. Get your allocation right first (Chapter 12), then locate.

LOW-INCOME YEARS

Gain harvesting at 0%

In a year when taxable income lands under $49,450 single / $98,900 joint (a sabbatical, early retirement, a between-jobs year), long-term gains are taxed at 0%. Sell winners, pay nothing federal, and rebuy to reset your basis higher. The mirror image of loss harvesting.

MOST POWERFUL

Donate appreciated stock, not cash

Give shares that went up instead of dollars: you skip the capital-gains tax on the growth, and the charity gets full value. The IRS rewards generosity; this is how to maximize every dollar you give. Note 2026's fine print: charitable deductions now carry a 0.5%-of-AGI floor, and top-bracket itemizers get at most a 35% benefit.

NEW IN 2026

The non-itemizer charitable deduction

You no longer need to itemize to get credit for giving: cash gifts up to $1,000 (single) or $2,000 (joint) are deductible on top of the standard deduction. Small, simple, and most filers qualify.

HIGH EARNERS

Direct indexing

Owning the individual stocks of an index instead of the fund, so losses can be harvested stock by stock. Useful for high earners with large taxable accounts and steady gains to offset. For everyone else it adds complexity, fees, and hundreds of positions for a benefit that fades over time.

DISCIPLINE REQUIRED

Concentrated-stock strategies

Exchange funds, charitable trusts, collars, staged sales: real tools for a Maya-sized position (Chapter 18), each with real costs, lockups, and complexity. The rule that governs all of them: every advanced strategy needs an endgame. If you can't say when the position reaches its target size and the strategy ends, you don't have a strategy, you have a stall.

Never let the tax tail wag the investment dog. Use marginal rates to judge each move, harvest losses and 0%-bracket gains when life hands them to you, and adopt an advanced strategy only if you can state its endgame in one sentence.

A note on order: the wrappers in Chapter 16 (401(k)s, IRAs, HSAs) usually beat everything in this toolkit, because they shelter money completely instead of trimming the bill. Fill those first; harvest and locate with what's left in taxable.

Where people go wrong

  • Refusing raises or overtime "to stay in a lower bracket." That loss is impossible. Only the dollars above the line are taxed at the higher rate.
  • Selling winners at month 11. Wait for month 13 and the federal rate can drop by 15 points or more.
  • Harvesting a loss, then rebuying the same fund a week later. That's a wash sale; the loss is disallowed.
  • Letting taxes veto good decisions. Holding a bad, oversized position forever to avoid a gains bill is how concentration problems (Chapter 13) become permanent.

Key takeaways

  • Brackets are a staircase: each rate taxes only its own slice. Your marginal rate guides decisions; your effective rate is what you actually paid.
  • In 2026 a single filer's standard deduction is $16,100; on $90,000, Jamie's marginal rate is 22% but the effective bite is about 12%.
  • Held longer than 12 months, gains are taxed at 0/15/20% instead of ordinary rates: at the top, 23.8% vs 40.8%.
  • The toolkit, in order of usefulness: harvest losses ($3,000/yr against ordinary income), locate assets, harvest 0% gains in low-income years, donate appreciated stock, claim the new $1,000/$2,000 non-itemizer deduction.
  • Every advanced strategy needs an endgame.

Sources: IRS: 2026 Tax Inflation Adjustments · IRS: Federal Income Tax Rates and Brackets · Tax Foundation: 2026 Tax Brackets · IRS: Publication 550, Investment Income