How U.S. Income Taxes Actually Work: A Guide to the Progressive Tax System

A raise, a bonus, or an extra IRA withdrawal won't push all of your income into a higher tax bracket. A lot of people think it does, and it costs them real money. They turn down income, skip Roth conversions, or leave retirement withdrawals on the table because of how they think the brackets work.

Here's how the math actually works, using the 2026 numbers the IRS has published. Once you see it, a lot of decisions about withdrawals, conversions, and bonuses get easier.

What "progressive" means

The U.S. federal income tax is a progressive tax. That word gets used politically, but in tax terms it just means one thing: the rate goes up as your income goes up, and the higher rates only apply to the income above each threshold.

Think of it like a set of buckets. The first bucket holds a certain amount of income and is taxed at 10%. Once that bucket is full, the next dollar spills into the second bucket, which is taxed at 12%. Then 22%, and so on. Your income fills the buckets in order. The money in the first bucket is always taxed at 10%, no matter how many buckets you eventually fill.

That is the whole idea. Nobody pays 37% on all of their income. A person in the 37% bracket pays 37% only on the portion of taxable income above the top threshold. Everything below that is taxed at the lower rates, the same as everyone else.

The 2026 federal income tax brackets

There are seven federal brackets. These are the thresholds for tax year 2026, the return you'll file in early 2027.¹ ² They apply to taxable income, which is what's left after your deductions (more on that below).

Single filers

Married filing jointly

Head of household

A quick note on where these come from. These seven rates were set by the 2017 Tax Cuts and Jobs Act and were scheduled to expire after 2025. The One Big Beautiful Bill Act, signed in July 2025, made them permanent.³ The dollar thresholds still move up each year with inflation, which is why the numbers change even though the rates don't.

How the IRS gets from your paycheck to your tax bill

Before any of those brackets matter, your income goes through a few steps. This is the part most people skip, and it's where a lot of planning opportunities live.

Step one: gross income. Wages, interest, dividends, business income, IRA and 401(k) withdrawals, pension payments, rental income, capital gains, and the taxable portion of Social Security. Basically everything.

Step two: adjustments. Certain items come off the top before you get to adjusted gross income, or AGI. Traditional IRA contributions, HSA contributions, and half of self-employment tax are common examples. AGI matters beyond your tax bill, because things like Medicare premium surcharges and many phase-outs are based on it.

Step three: deductions. From AGI, you subtract either the standard deduction or your itemized deductions, whichever is larger. For 2026, the standard deduction is $16,100 for single filers, $32,200 for married couples filing jointly, and $24,150 for heads of household.¹ If you're 65 or older, you get an additional $1,650 per person if married, or $2,050 if single.⁴ On top of that, through 2028 there's a separate $6,000 deduction per person age 65 and over, which starts phasing out at $75,000 of modified AGI for single filers and $150,000 for joint filers.⁵ We wrote about that one in detail here.

What's left after deductions is your taxable income. That's the number that runs through the brackets.

Step four: credits. After you calculate the tax, credits reduce it dollar for dollar. The child tax credit is the one most families know.

The important takeaway: the brackets above apply to taxable income, not to your salary. A married couple earning $150,000 in wages with no other deductions has taxable income of $117,800, not $150,000.

A worked example

Let's use that couple. Married, filing jointly, $150,000 in wages, taking the standard deduction.

Taxable income: $150,000 minus $32,200 = $117,800

Here's how that flows through the brackets:¹ ²

• First $24,800 taxed at 10% = $2,480
• Next $76,000 (from $24,801 to $100,800) taxed at 12% = $9,120
• Remaining $17,000 (from $100,801 to $117,800) taxed at 22% = $3,740

Total federal income tax: $15,340

This couple is "in the 22% bracket." But look at what they actually paid. $15,340 on $150,000 of wages works out to a little over 10%. Only $17,000 of their income was taxed at 22%. Most of it was taxed at 12%.

Marginal rate versus effective rate

That example illustrates the two numbers you should know about your own situation.

Your marginal rate is the rate on your next dollar of income. For the couple above, it's 22%. This is the number that matters when you're deciding whether to take an extra IRA withdrawal, do a Roth conversion, or defer a bonus into next year. Every additional dollar (up to the next threshold) costs 22 cents in federal tax, and every dollar you can deduct saves 22 cents.

Your effective rate is your total tax divided by your total income. For the couple above, it's about 10.2%. This is what you actually paid, all in. It's always lower than your marginal rate in a progressive system.

When people say "I'm in the 32% bracket, so a third of my money goes to taxes," they're mixing up the two. Let me show you with a higher earner.

Single filer, $250,000 in wages, standard deduction. Taxable income is $233,900.¹ ²

• $12,400 at 10% = $1,240
• $38,000 at 12% = $4,560
• $55,300 at 22% = $12,166
• $96,075 at 24% = $23,058
• $32,125 at 32% = $10,280

Total: $51,304

This person is in the 32% bracket. Their effective federal income tax rate is about 20.5% of gross wages. Only $32,125 of their $250,000 was actually taxed at 32%.

The raise that "costs you money" myth

Back to the myth from the start of this post. Can earning more ever leave you with less after federal income tax?

Under the bracket system, no. If a single filer's taxable income goes from $50,400 to $51,400, only that extra $1,000 gets taxed at 22% instead of 12%.¹ The tax on the first $50,400 doesn't change at all. You keep $780 of the extra $1,000. You never come out behind.

Where this idea gets some traction is in the things tied to your income other than the brackets themselves. Medicare IRMAA surcharges, the phase-out of certain deductions and credits, and the taxation of Social Security benefits all have thresholds where crossing a line by one dollar can cost real money. Those are cliffs, and they're worth planning around. But they're separate from the bracket system, and the brackets themselves never punish you for earning more.

Where the system is not progressive

The federal income tax is progressive. Not everything on your pay stub is.

Social Security tax is 6.2% on wages up to $184,500 in 2026, and zero above that.⁶ Someone earning $500,000 pays the same dollar amount of Social Security tax as someone earning $184,500. The self-employed pay both halves, 12.4%, up to the same limit.⁶

Medicare tax is 1.45% on all wages with no cap, plus an additional 0.9% on wages above $200,000 for single filers and $250,000 for joint filers.⁶

Long-term capital gains and qualified dividends run through their own separate set of brackets: 0%, 15%, and 20%. For 2026, the 0% rate applies up to $49,450 of taxable income for single filers and $98,900 for married couples filing jointly. The 20% rate kicks in above $545,500 for singles and $613,700 for joint filers.² Investors with modified AGI above $200,000 (single) or $250,000 (joint) may also owe the 3.8% net investment income tax on top of that.⁷

This matters for retirees in particular. Someone living on a mix of Social Security, qualified dividends, and long-term gains can end up with a surprisingly low federal tax bill, while a neighbor pulling the same dollars out of a traditional IRA pays ordinary income rates on all of it.

Who actually pays federal income tax

Because the system is progressive, the tax burden is concentrated at the top. The most recent IRS data compiled by the Tax Foundation, for tax year 2023, shows:⁸

• The top 1% of earners (AGI above $675,602) earned 20.6% of all adjusted gross income and paid 38.4% of all federal income taxes.
• The top 10% paid 70.5% of federal income taxes.
• The bottom 50% of earners (AGI below $53,801) earned 12.3% of income and paid 3.3% of federal income taxes.
• The average income tax rate was 26.3% for the top 1%, 3.7% for the bottom half, and 14.1% across all taxpayers.

I'm not sharing that to make a political point either way. It's just useful context for understanding what "progressive" means in practice. The higher your income, the larger the share of it that goes to federal income tax, and the more valuable careful planning becomes.

A little history

The modern federal income tax dates to 1913, when the 16th Amendment was ratified. That first year, rates ran from 1% to 7%, and the 7% rate only applied to income over $500,000, which was an enormous sum at the time.⁹

Rates climbed sharply to pay for two world wars. In 1944, the top rate hit 94% on income over $200,000. Through the 1950s, 60s, and 70s the top rate never dropped below 70%. The Tax Reform Act of 1986 brought it down to 28% starting in 1988, and it has moved between 28% and 39.6% since.⁹ Today's top rate of 37% is now permanent under the One Big Beautiful Bill Act, at least until Congress changes it again.³

The point of the history lesson: brackets are a policy choice, and they've changed many times. Building a plan that assumes today's rates last forever is a bet. Diversifying between pre-tax, Roth, and taxable accounts gives you some flexibility no matter which direction rates move.

Why this matters if you're retired or close to it

Here's where understanding the progressive system starts to pay off.

Once you stop working, you often have more control over your taxable income than at any other point in your life. You decide how much to pull from the IRA, whether to convert some of it to Roth, when to claim Social Security, and which account to sell from when you need cash. Each of those choices determines which buckets get filled.

Take a retired couple, both over 65, with $90,000 of pension and IRA income and no other deductions. For 2026 they get the $32,200 standard deduction, another $3,300 for being over 65, and the $6,000 senior deduction each.¹ ⁴ ⁵ That's $47,500 in deductions and $42,500 of taxable income, well inside the 12% bracket. The 12% bracket runs to $100,800 for joint filers, so this couple has about $58,300 of room left in it.¹

That room is an opportunity. Converting some traditional IRA money to Roth this year at 12% may make a lot more sense than leaving it to be withdrawn later at 22% or 24%, especially once required minimum distributions begin or one spouse passes away and the survivor starts filing as a single person with half the bracket width. Whether it's the right move depends on the full picture, including state taxes, IRMAA, and how Social Security is taxed. But you can't even ask the question without first knowing where you sit in the brackets.

The same logic applies to high earners still working. Knowing your marginal rate tells you exactly what a 401(k) contribution, an HSA contribution, or a charitable gift is worth to you in tax savings this year.

The bottom line

The U.S. income tax is progressive, which means your income is taxed in layers, and only the top layer is taxed at your bracket rate. Your effective rate is always lower than your marginal rate. A raise or an extra withdrawal never leaves you with less after federal income tax, though it can trigger other income-based costs worth watching.

If you haven't looked at your own return with these ideas in mind, it's worth doing. We review tax returns as part of the financial planning process, because the return is where you can see which buckets you're filling and whether there's a better way to fill them. If you'd like a second set of eyes on yours, give our office a call at 920-380-7056 or email hello@dreyerwealth.com.

This material is for general informational and educational purposes only and should not be considered tax or legal advice. Tax laws are subject to change. The examples above are hypothetical, use federal figures only, and do not account for state taxes, credits, or individual circumstances. Please consult your tax professional regarding your specific situation.

Sources

1. Internal Revenue Service, "IRS releases tax inflation adjustments for tax year 2026, including amendments from the One, Big, Beautiful Bill" (IR-2025-103, October 9, 2025): https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill
2. Internal Revenue Service, Revenue Procedure 2025-32 (2026 tax rate tables, standard deduction, capital gains thresholds): https://www.irs.gov/pub/irs-drop/rp-25-32.pdf
3. Tax Foundation, "2026 Tax Brackets and Federal Income Tax Rates": https://taxfoundation.org/data/all/federal/2026-tax-brackets/
4. Current Federal Tax Developments, "2026 Inflation Adjustments for Tax Professionals: Revenue Procedure 2025-32 Analysis" (additional standard deduction for age 65 and older): https://www.currentfederaltaxdevelopments.com/blog/2025/10/9/2026-inflation-adjustments-for-tax-professionals-revenue-procedure-2025-32-analysis
5. Internal Revenue Service, "Working Families Tax Cuts: Tax deductions for working Americans and seniors" (senior deduction details): https://www.irs.gov/newsroom/one-big-beautiful-bill-act-tax-deductions-for-working-americans-and-seniors
6. The Tax Adviser (AICPA), "Social Security wage base and COLA announced for 2026": https://www.thetaxadviser.com/news/2025/oct/social-security-wage-base-and-cola-announced-for-2026/
7. Internal Revenue Service, "Net Investment Income Tax": https://www.irs.gov/individuals/net-investment-income-tax
8. Tax Foundation, "Summary of the Latest Federal Income Tax Data, Tax Year 2023": https://taxfoundation.org/data/all/federal/who-pays-federal-income-taxes-tax-year-2023/
9. Bradford Tax Institute, "History of Federal Income Tax Rates: 1913 - 2026": https://bradfordtaxinstitute.com/Free_Resources/Federal-Income-Tax-Rates.aspx