Deductions, Credits and a Yearly Tax Check-Up

Most people meet their tax situation once a year, in a rush, with whatever paperwork they can find. By then nearly every choice that could have lowered the bill is closed. This chapter walks the path from your income to your tax: the adjustments that lower your income, the choice between the standard deduction and itemizing, the new deductions that run from 2025 through 2028, and the credits that cut your tax directly. It ends with a short yearly check-up you can run in an evening. Figures are the 2026 federal amounts.

The path from income to tax

Every federal return follows the same sequence, and knowing it tells you where each tax break acts.

1. Total income: wages, business profit, interest, dividends, gains and other income.
2. Minus adjustments (often called above-the-line deductions) gives adjusted gross income, or AGI.
3. Minus the standard deduction or itemized deductions, and any of the new deductions, gives taxable income.
4. Tax from the brackets (chapter 1), with lower rates for qualified dividends and long-term gains (chapter 3).
5. Minus credits, plus other taxes such as self-employment tax.
6. Minus what you already paid through withholding and estimated payments gives your refund or balance due.

AGI matters beyond step 3. Many limits are set by AGI or a modified version of it: who can contribute to a Roth IRA, who gets certain credits, how much of Social Security is taxed, the medical expense floor and the net investment income tax. A break that lowers AGI therefore tends to be worth more than one that only lowers taxable income.

Adjustments: the breaks everyone can use

Adjustments are available whether or not you itemize. The most common ones:

• Pre-tax workplace retirement contributions to a 401(k), 403(b) or similar plan, up to $24,500 of your own pay in 2026. These come out of your wages before they reach the return, so they lower AGI automatically.
• Deductible traditional IRA contributions, up to $7,500, subject to income limits if you have a workplace plan.
• Health savings account contributions, up to $4,400 with self-only coverage or $8,750 with family coverage, if you have a qualifying high-deductible health plan.
• For the self-employed: half of self-employment tax, health insurance premiums and retirement plan contributions (chapter 5).
• Student loan interest and educator expenses, each up to a limit.

Here is what a pre-tax contribution does for a single filer.

Moving the difference between $90,000 and $80,000 into pre-tax accounts lowers federal income tax from $10,970 to $8,770, and lowers AGI by the full amount. HSA contributions made through payroll also skip Social Security and Medicare tax, which makes them one of the few breaks that cut every federal layer at once.

Standard deduction or itemizing

After adjustments you subtract either the standard deduction or the total of your itemized deductions, whichever is larger. For 2026 the standard deduction is $16,100 for a single filer, $24,150 for head of household and $32,200 for a couple filing jointly. Most households take it.

Itemized deductions are mainly these four:

• State and local taxes: income or sales tax plus property tax, capped at $40,400 per return for 2026. The cap shrinks by 30% of modified AGI above $505,000, but not below $10,000.
• Mortgage interest on debt used to buy, build or improve your main or second home, within the debt limits in IRS Publication 936.
• Charitable gifts. From 2026, itemizers can deduct only the part of their gifts above 0.5% of AGI.
• Medical and dental costs above 7.5% of AGI.

Two changes in 2026 help people who do not itemize. A non-itemizer can now deduct cash gifts to charity of up to $1,000, or $2,000 on a joint return. And if your itemized total sits close to the standard deduction, bunching two years of gifts into one, often through a donor-advised fund, can let you itemize every other year. The standard vs itemized deduction calculator does the comparison with the 2026 limits.

The new deductions for 2025 through 2028

The 2025 tax law added four temporary deductions. Each is taken on top of the standard or itemized deduction, each shrinks above an income level, and none lowers AGI:

• Qualified tips: up to $25,000 a year, for tips in occupations that customarily received them.
• Qualified overtime: the extra part of overtime pay above the regular rate, up to $12,500, or $25,000 on a joint return.
• Car loan interest: up to $10,000 of interest on a loan for a new, US-assembled passenger vehicle bought for personal use.
• Seniors: an extra $6,000 for each person aged 65 or older.

These are new and the IRS is still issuing guidance on them, so check the IRS page in this chapter's sources before relying on one. The new tax deductions calculator estimates what each would save you.

Credits: worth more per dollar

A deduction lowers taxable income, so it saves tax at your marginal rate. A credit is subtracted from the tax itself, dollar for dollar. For someone in the 22% bracket, a deduction saves 22 cents per dollar and a credit saves a full dollar.

Credits come in two kinds. A nonrefundable credit can bring your tax down to zero but no further. A refundable credit can be paid to you even if you owe no tax. Some, like the child tax credit, are partly refundable.

The credits most households should check:

• Child tax credit and the credit for other dependents
• Child and dependent care credit, for care that lets you work
• Earned income tax credit, for workers with low to moderate income
• American Opportunity and Lifetime Learning credits, for college costs
• Saver's credit, for retirement contributions by people with modest income
• Premium tax credit, for health insurance bought through the marketplace

The amounts and income limits change often, some yearly with inflation and some by new law, and several energy credits ended in 2025. Look up each credit's current rules on IRS.gov rather than relying on an amount you remember.

A yearly tax check-up

Run this once a year, ideally in the autumn while there is still time to act, and again whenever your life changes: marriage or divorce, a new child, a home purchase, a new job or side business, a large investment gain, a move to another state, or turning 50 or 65.

1. Income. List every source you expect this year and its type (chapter 3). Note anything new.
2. Adjustments. Check how much room is left in your 401(k), IRA and HSA for the year.
3. Deductions. Add up likely itemized deductions and compare them with the standard deduction. Decide whether bunching makes sense.
4. Credits. Go through the list above and note any you may now qualify for or lose.
5. Payments. Compare what has been withheld or paid so far with what you expect to owe. Chapter 6 shows how.
6. Records. Keep returns and the records that support them for at least three years after filing; some situations, such as unreported income or property you still own, call for longer.

Accuracy also protects you. The IRS matches the forms that employers, banks and brokers send it against your return, so the most common trigger for a letter is income left off. Report everything, and keep receipts for every deduction you claim.