Adjusted Gross Income (AGI)

Adjusted gross income (AGI) is generally an individual taxpayer’s gross income after subtracting the adjustments to income allowed under federal tax law. It is an intermediate figure in the federal individual income-tax calculation, falling between gross income and taxable income.

Internal Revenue Code Section 62 defines adjusted gross income by reference to gross income reduced by specified deductions. AGI then serves as an income measure for certain deduction limits, tax benefits, estimated-tax rules, and other federal and state tax calculations.

How -s AGI Calculated? 

Adjusted gross income is calculated by subtracting allowable adjustments to income from gross income included under federal tax rules.

The simplified calculation is:

Gross income − allowable adjustments to income = adjusted gross income (AGI)

The calculation flows through Form 1040, U.S. Individual Income Tax Return, and, when applicable, Schedule 1, Additional Income and Adjustments to Income. Schedule 1 is used to report additional income and adjustments that cannot be entered directly on Form 1040. Because forms, schedules, and line numbers can change between tax years, tax professionals should verify the applicable version for the year being prepared rather than relying on historical line references.

Step 1: Determine Gross Income

Start by identifying the income items that are included in gross income under federal tax law and determining the taxable amount of each item that applies to the taxpayer.

Depending on the taxpayer’s circumstances, income included in the AGI calculation can include:

• Wages, salaries, and taxable tips

• Taxable interest

• Ordinary dividends

• Taxable IRA distributions

• Taxable pensions and annuities

• The taxable portion of Social Security benefits

• Net capital gain or loss, subject to applicable capital-loss limitations and carryforward rules

• Business income or loss

• Rental and royalty income

• Partnership and S corporation income or loss

• Estate and trust income

• Unemployment compensation

• Other taxable income

IRC Section 61, Gross Income Defined broadly includes compensation, business income, gains from property, interest, rents, royalties, dividends, annuities, pensions, partnership income, and income from estates or trusts, unless another tax rule provides otherwise.

W-2 wages are therefore only one possible component of the income used to determine AGI. A taxpayer may also have business, investment, retirement, pass-through, or other taxable income.

For broader context on how these income sources fit into an individual return, see CPA Pilot’s U.S. Tax System Explained.

Step 2: Subtract Adjustments From Gross Income 

Next, identify deductions that are allowed before AGI is determined.

The current finalized Schedule 1, Additional Income and Adjustments to Income includes adjustment categories such as:

• Educator expenses

• Certain business expenses of eligible reservists, performing artists, and fee-basis government officials

• Health Savings Account deduction

• Moving expenses for eligible members of the Armed Forces

• Deductible part of self-employment tax

• Self-employed SEP, SIMPLE, and qualified retirement-plan deductions

• Self-employed health insurance deduction

• Penalty on early withdrawal of savings

• Alimony or separate-maintenance payments deductible under the applicable pre-2019 instrument rules

• IRA deduction

• Student loan interest deduction

• Archer MSA deduction

• Other specifically allowable adjustments

These adjustments are commonly called above-the-line deductions because they reduce income before AGI is finalized.

Each adjustment has its own eligibility, limitation, and documentation requirements. The fact that an adjustment appears on Schedule 1 does not mean every taxpayer qualifies to claim it.

Step 3: Calculate Adjusted Gross Income 

After gross income and allowable adjustments have been determined, subtract the adjustments from gross income.

The result is AGI.

That amount then becomes the starting income figure for deductions and calculations applied later in the return.

Which Deductions Do Not Reduce Adjusted Gross Income?

Not every federal income-tax deduction reduces AGI. Several important deductions are applied after AGI has already been determined and instead reduce taxable income.

Does the Standard Deduction Reduce AGI?

No. The standard deduction reduces taxable income, not AGI.

For tax year 2026, the basic standard deduction amounts are:

• $16,100 for single filers or married individuals filing separately

• $32,200 for married couples filing jointly or qualifying surviving spouses

• $24,150 for heads of household

The IRS confirms these amounts in its 2026 tax inflation adjustments. Different amounts or additional deductions can apply in certain circumstances.

Do Itemized Deductions Reduce AGI?

No. Itemized deductions are generally taken after AGI is determined.

Taxpayers who itemize use Schedule A, Itemized Deductions. Schedule A can include qualifying medical expenses, state and local taxes, interest, charitable contributions, and other allowable deductions.

AGI can still affect whether, or to what extent, certain itemized deductions are deductible.

For example, qualifying medical and dental expenses are generally deductible only to the extent they exceed 7.5% of AGI. The rule is explained in IRS Publication 502, Medical and Dental Expenses.

Beginning in 2026, taxpayers who itemize generally may deduct qualifying charitable contributions only to the extent those contributions exceed 0.5% of AGI, subject to the other charitable-contribution limitations that may apply. The IRS incorporates this 2026 floor into its current guidance. (Source)

Does the QBI Deduction Reduce AGI?

No. The Section 199A qualified business income deduction is calculated after AGI and reduces taxable income rather than AGI.

Eligible taxpayers generally calculate the deduction using Form 8995, Qualified Business Income Deduction Simplified Computation or Form 8995-A, Qualified Business Income Deduction.

Public Law 119-21, Section 70105 extended and enhanced the Section 199A deduction, with the amendments applying to tax years beginning after December 31, 2025. IRS guidance also confirms that the QBI deduction is permanent under the current law.

For qualification rules, W-2 wage and property limitations, SSTB treatment, and current Section 199A rules, see CPA Pilot’s Qualified Business Income Deduction guide.

Do Schedule 1-A Deductions Reduce AGI?

No. Schedule 1-A deductions are applied after AGI and reduce taxable income instead.

Schedule 1-A, Additional Deductions covers deductions involving:

• Qualified tips eligible for the applicable deduction

• Qualified overtime compensation eligible for the applicable deduction

• Qualified passenger-vehicle loan interest

• The enhanced deduction for seniors

The IRS’s 2026 estimated-tax calculation also places these additional deductions after projected AGI when taxable income is determined.

Where Can You Find Adjusted Gross Income on a Tax Return?

AGI is calculated and reported on Form 1040 after total income and adjustments to income have been determined.

Tax professionals should use the Form 1040 for the applicable tax year because line numbering and form layout can change.

The return flow is:

Income → additional income and adjustments through Schedule 1 → AGI → post-AGI deductions → taxable income

For CPA workflows involving the complete individual return, see CPA Pilot’s 1040 tax preparation workflow guide.

How Do You Find Prior-Year AGI?

Prior-year AGI can generally be obtained from the originally filed prior-year return or IRS records.

A taxpayer can:

• Review the prior-year Form 1040

• Use an IRS Online Account

• Obtain an IRS tax return transcript

Prior-year AGI may also be required to electronically sign and validate an electronically filed federal return. The IRS explains this process in its electronic return validation guidance.

For prior-year AGI mismatches and related filing errors, see CPA Pilot’s IRS Rejection Codes guide.

Gross Income vs. AGI vs. Taxable Income: Key Differences 

Gross income, AGI, and taxable income represent different stages of the federal tax calculation.

In sequence, the calculation generally moves from gross income → AGI → taxable income, with different deductions applying at each stage. 

Why Does Adjusted Gross Income Matter for Taxes?

AGI matters because tax law can use it as a threshold, limitation base, filing input, or starting point for another income calculation.

The effect depends on the specific provision being applied.

How Can AGI Affect Deductions & Limitations?

Some deductions use AGI directly when determining how much is deductible.

For example:

• Medical expenses are generally subject to a 7.5% of AGI threshold.

• Itemized charitable contributions are subject to AGI-based rules, including the new 0.5% floor beginning in 2026, along with other applicable percentage limitations.

• A change in AGI can require related deduction or credit calculations to be recomputed.

The Instructions for Form 1040-X, Amended U.S. Individual Income Tax Return, specifically explain that a change in AGI can affect credits, charitable deductions, taxable Social Security benefits, and total itemized deductions.

Do All Tax Credits Use AGI?

No. Different tax provisions use different definitions of income.

Depending on the rule, eligibility may be based on:

• AGI

• Modified adjusted gross income

• Earned income

• Taxable income

• Another specifically defined income measure

When a provision uses modified adjusted gross income (MAGI), AGI commonly serves as a starting point, but the required modifications depend on that specific tax provision.

How Can Federal AGI Affect State Income Tax Returns?

A state may begin its individual income-tax calculation with federal AGI and then apply state-specific additions or subtractions.

For example, California Schedule CA (540) is used to make California adjustments to federal adjusted gross income and federal itemized deductions. New York likewise calculates New York adjusted gross income by applying state additions and subtractions to federal AGI through its Form IT-201 instructions. 

State conformity can change, so CPAs should verify the applicable state rules for the tax year rather than assuming federal AGI carries over unchanged.

For the broader workflow, see CPA Pilot’s Federal vs. State Tax guide.

How Does AGI Affect Estimated Tax Safe Harbors?

Prior-year AGI can determine whether the 100% or 110% prior-year-tax safe-harbor percentage applies to certain higher-income taxpayers.

For 2026 estimated tax, taxpayers generally compare withholding and estimated payments with the applicable current-year and prior-year tax tests, subject to the general estimated-tax requirements.

If 2025 AGI exceeded $150,000, or $75,000 when the taxpayer’s 2026 filing status is married filing separately, the prior-year percentage generally increases from 100% to 110%. This higher-income rule does not apply when at least two-thirds of gross income for 2025 or 2026 is from farming or fishing. (Source)

This is an intentional 2025 reference: the 2026 safe-harbor test looks back to the taxpayer’s 2025 AGI.

Taxpayers can use Form 1040-ES, Estimated Tax for Individuals, together with IRS Publication 505 for 2026 when determining estimated-tax requirements.

For forward-looking client scenarios, see CPA Pilot’s AI for Tax Projection guide.

Why Do CPAs Review Adjusted Gross Income?

CPAs review AGI because it is a key reconciliation point between income reported on the return and tax calculations that depend on that income.

A professional AGI review can include:

• Reconciling wage and other income documents

• Checking taxable retirement and investment income

• Confirming business and pass-through income flowed correctly

• Reviewing Schedule 1 adjustments and supporting documentation

• Comparing current-year AGI with the prior-year return

• Investigating material year-over-year changes

• Identifying deductions or credits that must be recalculated when AGI changes

• Confirming the correct starting amount when another provision uses MAGI

• Checking prior-year AGI when estimated-tax safe-harbor rules apply

Employment income may begin with Form W-2, Wage and Tax Statement, while business, rental, investment, or pass-through activity can require additional forms and schedules before the final AGI figure is established.

The review flow is:

Source documents → income schedules → adjustments → AGI → downstream tax calculations

CPA Pilot’s High-Income 1040 Review Checklist provides additional context for returns involving NIIT, AMT, SALT, Section 199A, pass-through income, and loss limitations.

For client communication after a completed return is reviewed, CPA Pilot’s AI Tax Return Summary surfaces AGI alongside other key return figures in a client-readable format.

Adjusted Gross Income FAQs

Can adjusted gross income be negative?

Yes. AGI can be negative when allowable losses and adjustments exceed taxable income. Loss-limitation rules may restrict how much of a loss can reduce AGI in the current tax year.

Is adjusted gross income the same as household income?

No. AGI is a federal tax-return measure, while household income can include income from multiple people and may use a different definition depending on the program or tax rule.

Can filing status affect adjusted gross income?

Yes. Filing status can affect AGI because it determines whose income is reported together and can change eligibility or limits for certain adjustments to income.

Does tax-exempt income count toward adjusted gross income?

Generally, tax-exempt income does not increase federal AGI. However, some excluded income can still affect other calculations, including Social Security taxation or provision-specific MAGI tests.

Can an amended tax return change adjusted gross income?

Yes. Form 1040-X can change AGI when corrected income or adjustments alter the original return. A revised AGI may also require recalculating deductions, credits, or other income-based tax items.