Understanding Tax Deductions: What You Can Write Off

Quick answer

• Tax deductions reduce your taxable income, lowering your overall tax bill.
• Common deductions include those for student loan interest, certain medical expenses, and contributions to retirement accounts.
• You can choose between the standard deduction or itemizing deductions, whichever saves you more.
• Keeping good records is crucial for supporting any deductions you claim.
• Understanding which expenses are deductible is key to maximizing your tax savings.

What to check first (before you file or change withholding)

Filing Status

Your filing status (Single, Married Filing Jointly, Married Filing Separately, Head of Household, Qualifying Widow(er)) significantly impacts your tax bracket and the standard deduction amount. Ensure you select the status that accurately reflects your circumstances.

Income Sources

Identify all sources of income, including wages, freelance earnings, investment income, and any other money received. This comprehensive view is essential for accurate tax reporting and determining eligibility for certain deductions.

Withholding or Estimated Payments

Review how much tax is being withheld from your paychecks or if you are making estimated tax payments. Adjusting withholding can prevent a large tax bill or an excessive refund, ensuring you’re not overpaying or underpaying throughout the year.

Deductions and Credits

Familiarize yourself with common tax deductions and credits. Deductions lower your taxable income, while credits directly reduce your tax liability. Understanding the difference and what you might qualify for can lead to significant savings.

Deadlines and Extensions

Be aware of tax filing deadlines. If you cannot file by the deadline, you can typically request an extension, but remember this is an extension to file, not an extension to pay any taxes owed.

Step-by-step (simple workflow)

1. Gather all income documents.

• What to do: Collect W-2s, 1099s (for freelance, interest, dividends, etc.), and any other statements showing income earned.
• What “good” looks like: You have a complete list of all income received from all sources for the tax year.
• A common mistake and how to avoid it: Missing a 1099 form for freelance work. Avoid this by diligently tracking all your income sources throughout the year and cross-referencing with bank statements.

2. Review your eligibility for the standard deduction.

• What to do: Check the IRS standard deduction amounts for your filing status.
• What “good” looks like: You know the standard deduction amount applicable to you.
• A common mistake and how to avoid it: Assuming you should itemize without comparing it to the standard deduction. Avoid this by calculating your potential itemized deductions first and then comparing the total to the standard deduction.

3. Determine if itemizing deductions is beneficial.

• What to do: Tally up all eligible expenses that can be itemized, such as medical expenses exceeding a certain percentage of your Adjusted Gross Income (AGI), state and local taxes (SALT) up to the limit, home mortgage interest, and charitable contributions.
• What “good” looks like: You have a clear total of your itemized deductions.
• A common mistake and how to avoid it: Forgetting to track eligible expenses throughout the year. Avoid this by using a spreadsheet or app to record deductible expenses as they occur.

4. Calculate your Adjusted Gross Income (AGI).

• What to do: Subtract “above-the-line” deductions (like IRA contributions, student loan interest, etc.) from your gross income.
• What “good” looks like: You have a calculated AGI.
• A common mistake and how to avoid it: Not understanding which deductions are “above-the-line.” Avoid this by consulting IRS publications or tax software that clearly defines these deductions.

5. Compare your total itemized deductions to the standard deduction.

• What to do: If your itemized deductions exceed the standard deduction for your filing status, you will itemize. Otherwise, take the standard deduction.
• What “good” looks like: You have chosen the deduction method that results in the lowest taxable income.
• A common mistake and how to avoid it: Choosing the standard deduction when itemizing would save more money. Avoid this by performing the comparison accurately.

6. Identify and document eligible “above-the-line” deductions.

• What to do: Keep records for deductions like educator expenses, health savings account (HSA) contributions, self-employment tax, IRA contributions, and student loan interest.
• What “good” looks like: You have organized proof for all claimed above-the-line deductions.
• A common mistake and how to avoid it: Claiming deductions for which you don’t have adequate documentation. Avoid this by keeping receipts and statements for all these expenses.

7. Identify and document eligible itemized deductions (if itemizing).

• What to do: Gather documentation for medical expenses (receipts, Explanation of Benefits), state and local taxes paid (tax bills, W-2s for income tax withholding), home mortgage interest statements (Form 1098), and charitable donation receipts.
• What “good” looks like: You have all necessary paperwork to support each itemized deduction.
• A common mistake and how to avoid it: Not meeting the AGI threshold for medical expense deductions. Avoid this by understanding the AGI limitation and only tracking expenses that might exceed it.

8. Claim qualifying tax credits.

• What to do: Research tax credits you may be eligible for, such as the Earned Income Tax Credit, Child Tax Credit, or education credits.
• What “good” looks like: You have identified all applicable tax credits and have the necessary documentation to claim them.
• A common mistake and how to avoid it: Confusing credits with deductions. Remember, credits directly reduce your tax owed, often providing a greater benefit than deductions.

9. Complete your tax return.

• What to do: Fill out your tax return forms accurately, entering your income, deductions, and credits.
• What “good” looks like: Your tax return is complete and accurately reflects your financial situation.
• A common mistake and how to avoid it: Simple data entry errors. Avoid this by double-checking all numbers and using tax software that can flag potential issues.

10. File your return.

• What to do: Submit your tax return electronically or by mail by the deadline.
• What “good” looks like: Your return has been successfully filed and you have confirmation.
• A common mistake and how to avoid it: Missing the filing deadline. Avoid this by filing early or filing for an extension well before the deadline.

Common mistakes (and what happens if you ignore them)

Mistake	What it causes	Fix
<strong>Not keeping records</strong>	Inability to support deductions if audited; missed opportunities for deductions.	Maintain organized records (receipts, statements, digital files) for all income and expenses. Reconstruct records if possible.
<strong>Choosing the wrong filing status</strong>	Paying more tax than necessary; potential penalties if corrected late.	Carefully review your options (Single, Married Filing Jointly, etc.) and choose the one that results in the lowest tax liability. Consult tax software or a professional if unsure.
<strong>Overlooking “above-the-line” deductions</strong>	Higher taxable income than necessary; missed tax savings.	Familiarize yourself with deductions like student loan interest, IRA contributions, and self-employment tax deductions. Ensure you claim all eligible ones.
<strong>Failing to compare standard vs. itemized deductions</strong>	Paying more tax than necessary by not choosing the most beneficial option.	Always calculate your potential itemized deductions and compare the total to the standard deduction amount for your filing status. Choose the larger amount.
<strong>Incorrectly calculating medical expense deductions</strong>	Claiming too much or too little, leading to disallowed deductions or audits.	Understand the AGI threshold for medical expenses. Only deduct expenses exceeding that percentage of your AGI. Keep meticulous records of all medical-related bills and payments.
<strong>Missing charitable contribution substantiation</strong>	Disallowed deductions for contributions; potential penalties.	Obtain proper written acknowledgments from charities for donations, especially for cash contributions over a certain amount or non-cash donations.
<strong>Claiming deductions for non-deductible expenses</strong>	Audit flags, disallowed deductions, and potential penalties.	Understand what qualifies as a deductible expense. For example, personal living expenses are generally not deductible. Consult IRS guidelines or a tax professional.
<strong>Not filing or paying on time</strong>	Penalties and interest charges, and potential liens or wage garnishment.	File for an extension if you cannot meet the deadline. Pay as much tax as you can by the original deadline to minimize interest and penalties.
<strong>Misunderstanding tax credits</strong>	Not claiming credits you’re entitled to, or claiming credits incorrectly.	Differentiate between deductions and credits. Research all applicable credits (e.g., education, child, earned income) and ensure you meet all eligibility requirements and have the necessary documentation.
<strong>Errors in reporting income</strong>	Underpaying taxes (leading to penalties and interest) or overpaying.	Thoroughly review all income statements (W-2s, 1099s) and ensure all income is reported. Use tax software to help catch discrepancies.

Decision rules (simple if/then)

• If your total eligible itemized deductions are greater than the standard deduction for your filing status, then itemize your deductions because this will reduce your taxable income more.
• If you are a student paying off loans, then check if you can deduct the student loan interest because this reduces your taxable income.
• If you incurred significant unreimbursed medical expenses that exceed a certain percentage of your Adjusted Gross Income (AGI), then itemize your deductions because these expenses may be deductible.
• If you made contributions to a traditional IRA or a Health Savings Account (HSA), then claim these as “above-the-line” deductions because they reduce your AGI.
• If you are self-employed, then deduct one-half of your self-employment taxes because this is an “above-the-line” deduction.
• If you are a teacher who paid for classroom supplies, then deduct educator expenses up to the annual limit because this is an “above-the-line” deduction.
• If you made qualifying charitable contributions, then keep detailed records and itemize your deductions because these can reduce your taxable income.
• If you own a home and pay mortgage interest, then itemize your deductions because this interest is often a significant deductible expense.
• If you have dependents, then explore tax credits like the Child Tax Credit because credits directly reduce your tax liability.
• If you are unsure about your eligibility for a deduction, then consult the IRS website or a tax professional because incorrect claims can lead to penalties.
• If you are self-employed and pay for health insurance, then you may be able to deduct health insurance premiums as an “above-the-line” deduction because this reduces your AGI.

FAQ

What is the difference between a deduction and a credit?

A deduction reduces your taxable income, meaning you pay tax on a smaller amount of money. A credit directly reduces the amount of tax you owe, dollar for dollar. Credits are generally more valuable than deductions.

How do I know if I should itemize or take the standard deduction?

You should compare the total of your eligible itemized deductions to the standard deduction amount for your filing status. Whichever amount is larger is the one you should use, as it will result in a lower tax bill.

What are “above-the-line” deductions?

These are deductions you can take whether you itemize or take the standard deduction. They are subtracted from your gross income to arrive at your Adjusted Gross Income (AGI). Examples include student loan interest and IRA contributions.

Can I deduct expenses for working from home?

For employees, the Tax Cuts and Jobs Act of 2017 suspended the miscellaneous itemized deduction for unreimbursed employee expenses, including home office expenses, through 2025. Self-employed individuals may still be able to deduct certain home office expenses.

What kind of records do I need to keep for deductions?

You need documentation that supports your claim. This can include receipts, canceled checks, bank statements, credit card statements, bills, and any other records that show the amount paid and for what purpose.

Are there limits on how much I can deduct?

Yes, many deductions have limits. For example, the deduction for state and local taxes (SALT) is capped, and medical expense deductions are limited to the amount exceeding a percentage of your AGI.

What if I discover a mistake on a past tax return?

You can file an amended tax return using Form 1040-X, Amended U.S. Individual Income Tax Return. You generally have three years from the date you filed the original return or two years from the date you paid the tax, whichever is later, to file an amended return.

How do I find out about new tax laws that might affect my deductions?

Stay informed by visiting the IRS website regularly, subscribing to IRS tax tips, or consulting with a tax professional. Tax laws can change, so staying updated is important.

What this page does NOT cover (and where to go next)

• Specific tax forms and schedules: This article provides general guidance; specific forms (like Schedule A for itemized deductions) and their instructions are necessary for filing.
• State and local tax deductions: Rules for state and local taxes can vary significantly from federal rules.
• Tax implications of investments: This covers general deductions; investment-specific deductions and capital gains/losses have their own complex rules.
• Business expenses for self-employed individuals: While some self-employment deductions are mentioned, detailed business expense accounting is a separate topic.
• International tax situations: This article focuses on U.S. domestic tax rules.