Filing a tax return can be intimidating—especially when you’re dealing with older tax years like 2015. Schedule A (Form 1040) is the form used to report itemized deductions, allowing taxpayers to list specific expenses, such as mortgage interest, medical costs, and charitable donations, to lower their taxable income. Understanding how to complete this form correctly can make a meaningful difference in how much tax you owe—or how much refund you’re entitled to receive.
Some filers use the standard deduction because it’s simpler, but others benefit more from itemizing. For 2015, the choice between these options depended on your filing status and the total of your deductible expenses. Taxpayers with significant mortgage interest, medical bills, or state and local taxes often found that itemizing reduced their overall tax liability. This guide explains how to determine if Schedule A applies to your situation and how to fill it out line by line using the IRS’s official 2015 instructions.
Whether you’re filing late, amending a past return, or clarifying old deductions, this step-by-step guide will help you navigate the process clearly and confidently. With the correct forms, accurate records, and a little organization, you can complete your 2015 Schedule A accurately and avoid unnecessary penalties or delays.
Understanding Schedule A (Form 1040) and Who Should File
Form 1040 is the standard federal individual income tax return used by U.S. taxpayers, and Schedule A is the attachment you complete if you decide to itemize deductions instead of taking the standard deduction. Itemizing allows you to list specific deductible expenses—such as medical costs, mortgage interest, state and local taxes, and charitable donations—to reduce your taxable income. If your total itemized deductions are higher than the standard deduction amount, using Schedule A can lower the amount of tax you owe.
Purpose of Schedule A
The primary purpose of Schedule A is to help you claim tax deductions that reflect your actual expenses during the year. Instead of a single flat deduction, you calculate the total of qualified deductions to see whether itemizing offers greater savings. Standard deductions include home mortgage interest, medical expenses above the allowed threshold, and contributions to qualified charities.
Eligibility Requirements
You should file Schedule A if you use Form 1040 and have married and titheable expenses that exceed your standard deduction for 2015. Taxpayers who file Form 1040A or 1040EZ are not eligible to itemize and must take the standard deduction. If you are married and filing separately, and your spouse itemizes, you are also required to itemize your deductions.
When to Itemize vs. Take the Standard Deduction
For Tax Year 2015, the standard deduction amounts were:
- Single or Married Filing Separately: $6,300
- Married Filing Jointly or Qualifying Widow(er): $12,600
- Head of Household: $9,250
Taxpayers who were 65 or older, or blind, received an additional standard deduction for each condition. If your total eligible deductions exceed your standard deduction, it makes financial sense to itemize.
How to Get the Correct IRS Forms for Tax Year 2015
Filing an old tax return requires using the exact forms and instructions from that year. The IRS updates its tax forms annually, so using a newer version for a 2015 return can lead to errors or processing delays. To ensure accuracy, always download and complete the 2015 versions of Form 1040, Schedule A, and any related attachments.
Steps to finding the Right IRS Forms
- Visit the IRS Prior-Year Forms Page: Go to the IRS Prior-Year Forms and Instructions page. Use the search bar to locate the 2015 versions of Form 1040 and Schedule A. Each form includes its own set of instructions tailored to that tax year’s laws.
- Download the Correct Files:
- Form 1040 (2015): Main income tax return
- Schedule A (Form 1040, 2015): Itemized deductions
- Schedule A Instructions (2015): Line-by-line guidance for calculating deductions
- Form 1040 (2015): Main income tax return
Save these PDFs to your computer before filling them out and printing a copy for mailing.
- Verify the year on each form: Ensure that "Tax Year 2015" is displayed at the top of the form. Using a form from any other year will cause the IRS to reject or delay your return.
- Filing Late or Amending a Return: If you’re filing late or amending a previous return, always submit the original 2015 form—not the current year’s version. Mail your completed return to the address listed in the 2015 instructions for your state of residence.
Following these steps ensures your documents match the IRS system for that year and prevents rejections, penalties, or notices caused by incorrect forms.
Step-by-Step Guide to Completing Schedule A (2015)
Follow these numbered steps to complete Schedule A accurately for the 2015 calendar year. Keep your 2015 receipts, Forms W-2/1098, bank statements, and acknowledgments nearby so each entry can be verified.
1) Confirm you should itemize: Add up potential deductions and compare them with your 2015 standard deduction based on filing status. If itemized amounts are higher, proceed with Schedule A to deduct eligible expenses.
2) Gather medical and dental records (Lines 1–4): Total the costs you paid in 2015 for doctor visits, hospital care, prescriptions, medical devices, and qualified insurance premiums. Compute 10% of AGI (7.5% if 65+). Only the excess over the threshold may be deducted. Keep dates and proof of payment.
3) Choose income tax or sales tax (Line 5): Elect either state/local income tax or general sales tax. For income tax, include withholding plus estimated tax payments made during 2015. For sales tax, use actual receipts or the IRS tables.
4) Add real estate and personal property taxes (Lines 6–8): Include property taxes based on assessed value and vehicle registration fees that are value-based. List any other deductible taxes and then total Lines 5–8.
5) Enter home mortgage interest and points (Lines 10–12): Report mortgage interest from Form 1098, plus correctly allocable points. If you paid interest to a seller, list their name, address, and TIN. Keep closing disclosures as support.
6) Include mortgage insurance and investment interest (Lines 13–14): Add qualified mortgage insurance premiums and any investment interest (attach Form 4952 if required). Sum Lines 10–14 on Line 15.
7) Record charitable contributions (Lines 16–19): Add cash gifts supported by bank or card records and non-cash gifts at fair market value. Use Form 8283 if total non-cash gifts exceed $500. Apply the 50%/30% AGI limits, and carry forward any excess.
8) Compute casualty and theft losses (Line 20): Use Form 4684. Each event must exceed $100, and total losses must exceed 10% of AGI. Retain insurance statements that show the date and reimbursement amounts.
9) Enter unreimbursed employee expenses (Lines 21–27): List ordinary and necessary job expenses such as travel, dues, tools, uniforms, and job-related education. Subtotal, apply 2% of the AGI floor, and enter only the excess. For self-employed individuals, please report business expenses on Schedule C instead.
10) Add other miscellaneous deductions (Line 28): Include items not subject to the 2% floor, such as gambling losses up to winnings and impairment-related work expenses. Maintain detailed logs and confirmations.
11) Apply any phaseout and total your deductions (Lines 29–30): If your income exceeds the 2015 threshold, your itemized deductions may be subject to reduction (Pease limitation). After making the adjustments, enter the final total on Line 30.
12) Transfer totals to Form 1040: Move the Line 30 amount to Form 1040, Line 40, then review other parts of your return for above-the-line deductions and credits that may also lower your tax.
13) Check for everyday cross-form interactions: Mortgage interest and taxes appear here, but items like student loan interest are usually handled elsewhere on Form 1040. Furthermore, confirm that any nonrefundable credit entries align with your records.
14) Review accuracy before mailing: Use the 2015 instructions from the IRS website and recheck math. Simple errors can delay processing and increase your balance if corrections are required.
15) File even if you cannot pay everything today: Always file your tax return by the due date to limit penalties. If needed, request an extension of up to six months to file, but remember that you must still pay what you can by the original deadline to avoid interest charges from the IRS.
16) Choose a payment option for any amount due: If a tax bill remains, consider an installment agreement submitted online with Form 9465. When you pay overtime, the IRS may still charge interest and penalties on the unpaid portion until the full amount is paid.
17) If you receive a notice, respond quickly: Should you fail to respond, IRS charges may grow. If circumstances explain late filing or payment, you can request penalty relief for reasonable cause.
18) Use official resources and security cues: When accessing IRS tools, look for the locked padlock icon in your browser and make sure the address is correct. This helps protect your information and money.
19) Consider professional help: A qualified tax professional can help you compare scenarios, organize documentation, and communicate with the IRS on your behalf to resolve questions about deductions or documentation.
20) Keep comprehensive records: Retain copies of returns, schedules, receipts, mileage logs, bank statements, and acknowledgments. Good records support your positions if examined later and set realistic expectations about what to expect if questions arise.
Practical note on payments and relief options
If unpaid taxes remain after filing, the IRS offers multiple paths to address the balance, including payment plans and relief options based on your tax situation. If you pay late, penalties accrue from the original due date, and the service may charge interest until the full amount is paid. If hardship prevents payment, you can explore alternatives and request relief when appropriate—backed by documentation and, where helpful, guidance from a professional.
Quick check before mailing
Sign the return, attach required statements, and confirm any attachments match the entries you claimed. Mail to the address in the 2015 instructions for your state. Include a check with the correct date and memo line if you will pay by mail; otherwise, use approved electronic methods to protect your information and speed posting.
Key Deadlines, Penalties, and Interest for 2015 Returns
Understanding the filing timelines and possible penalties for 2015 tax returns helps you avoid unnecessary costs and protect your refund rights. The original due date for 2015 federal income tax returns was April 18, 2016, because Washington, D.C., observed Emancipation Day on April 15. With an approved extension, you could file by October 17, 2016, but any balance owed still had to be paid by the April deadline to prevent additional charges.
Filing and Payment Penalties
If you missed the deadline, the IRS applies two main penalties.
- Failure-to-file penalty: 5 percent of the unpaid tax for each month or part of a month the return is late, up to a maximum of 25 percent of the unpaid tax.
- Failure-to-pay penalty: 0.5 percent per month on the unpaid balance until full payment is made. If you apply both penalties in the same month, the failure-to-file penalty decreases by the amount of the failure-to-pay penalty.
These penalties accumulate monthly and are capped at specific dollar limits, depending on the amount you owe. The longer you wait, the higher the total cost, so it’s wise to prepare and submit your return as soon as possible, even if you can’t pay right away.
Interest Charges and Time Limits
Interest begins on the due date of the return and continues until the balance is paid in full. The IRS compounds interest daily and adjusts rates quarterly based on federal short-term rates plus 3 percent. The statute of limitations for refunds is three years from the original due date, while the collection period for other types of unpaid tax debts is typically ten years.
Looking Ahead
Late filers can reduce or remove penalties by showing reasonable cause—such as illness, disaster, or reliance on incorrect advice—and by paying as much as possible when filing. Prompt payment prevents the loss of credits or overpayments and limits future interest. Keeping accurate records now also makes it easier to handle similar issues in the future or prove eligibility for penalty relief later.
Common Schedule A Mistakes and Audit Red Flags
Even small mistakes on Schedule A (Form 1040) can delay processing or trigger an IRS review. Knowing the most frequent errors helps you file accurately and avoid unnecessary stress. Always ensure that every deduction you claim is valid, properly calculated, and supported by relevant documentation.
Frequent Errors When Itemizing
- Mixing personal and deductible expenses: Only eligible expenses can be itemized. Individual costs, such as clothing or nonwork-related travel, are not deductible.
- Claiming both income and sales tax: Choose only one—either income tax or sales tax—for Line 5. Claiming both automatically raises concern with the IRS.
- Using incorrect medical limits: For the 2015 tax year, only unreimbursed medical expenses exceeding 10% of your adjusted gross income (AGI) qualify. If you are age 65 or older, the threshold is 7.5% of AGI.
- Overstating charitable contributions: Always use the fair market value of donated goods, not the original or replacement cost. Missing or incomplete receipts can trigger an audit.
- Misreporting mortgage interest: Deduct only interest on qualified home loans within the 2015 limits. Interest from personal loans or unrelated properties does not qualify.
- Ignoring the 2% AGI rule for job expenses: Only unreimbursed employee expenses exceeding 2% of your AGI are deductible.
Audit Triggers to Watch For
- Large itemized deductions compared to income can trigger an IRS review.
- Using rounded numbers or estimates instead of exact figures may increase your audit risk.
- Missing documentation, including receipts, mileage logs, and donation records, can raise concerns with the IRS.
- Unverified losses, such as casualty or theft claims without supporting documentation, are likely to draw the attention of the IRS.
How to Avoid Issues
Keep clear proof for every deduction—bank statements, receipts, and donation acknowledgments. Review all calculations, verify documentation, and consider consulting a tax professional if your deductions appear unusually high. Accurate preparation ensures your Schedule A remains compliant and audit-ready.
Options for Late Filers or Unpaid 2015 Balances
If you still haven’t filed your 2015 return or have a remaining balance due, there are several ways to bring your account current and reduce penalties. The IRS encourages taxpayers to file as soon as possible, even if full payment isn’t immediately available. Filing now stops the larger failure-to-file penalty and shows an effort to resolve your tax issue in good faith.
Installment Agreements (Form 9465)
An installment agreement allows you to pay what you owe in manageable monthly payments.
- Short-term plans (120 days or less): These plans do not require a setup fee and are best if you can pay your balance within four months.
- Long-term plans (more than 120 days): These agreements are available if you owe $50,000 or less in combined taxes, penalties, and interest. Setup fees vary depending on your payment method, and interest continues to accrue until the balance is fully paid.
You can apply for an installment agreement online through the IRS Payment Agreement Application or by mail using Form 9465. Monthly payments can be automatically withdrawn from your bank account, making it easier to stay current and avoid future collection notices.
Penalty Abatement and Reasonable Cause Relief
If you filed late or couldn’t pay due to circumstances beyond your control, you can request penalty relief.
- First-Time Penalty Abatement: Available if you’ve had a clean compliance history for the previous three years.
- Reasonable Cause Relief: Applies if illness, disaster, or misinformation prevented timely filing or payment.
The IRS reviews your explanation and supporting documentation to decide which relief applies. While penalties may be waived, interest on unpaid tax generally cannot be removed.
Offer in Compromise (OIC)
An Offer in Compromise (OIC) lets you settle your tax debt for less than you owe if paying in full would cause financial hardship. You’ll need to submit Form 656 and pay a nonrefundable application fee, along with an initial payment. The IRS evaluates income, assets, and reasonable living expenses to determine eligibility. If you can't pay your debt on time, approval may be your best option.
Currently Not Collectible (CNC) Status
If you’re unable to pay because doing so would make it impossible to meet basic living costs, you may request CNC status. The IRS will temporarily pause collection activity while continuing to track your account. Interest still accrues, but enforcement actions—like liens or levies—are halted until your financial situation improves.
How to Stay Compliant Going Forward
Once your 2015 return is resolved, take steps to stay up to date. Generally, keeping your tax payments up to date and maintaining records of withholdings or quarterly payments helps prevent future issues. Review your income and withholding each year to avoid incurring additional unpaid debt through accumulated penalties or interest. Staying proactive ensures peace of mind and keeps your filings accurate for years to come.
Example Case Study – Filing Schedule A for a Late 2015 Return
- Background: In 2025, a taxpayer discovers they never filed their 2015 tax return. Their 2015 income was $70,000, and they maintained records for medical bills, mortgage interest, property taxes, and charitable donations. Before filing, they compare the standard deduction of $6,300 (for single filers) with their total itemized deductions.
- Step 1: Medical Deductions: They incurred $8,500 in qualified medical and dental expenses. Since 10% of their adjusted gross income equals $7,000, only the $1,500 amount above that limit is deductible.
- Step 2: Taxes Paid: They include $3,200 in state income taxes and $2,600 in property taxes, totaling $5,800 in allowable deductions.
- Step 3: Interest and Charitable Contributions: Their Form 1098 lists $9,000 in mortgage interest, and they donated $1,200 to qualified charities with proper receipts.
- Step 4: Job Expenses: They record $900 in unreimbursed work-related expenses, but this sum is below the 2% of AGI floor ($1,400), so none qualify for a deduction.
- Step 5: Final Calculation and Filing: The total itemized deductions amount to $17,500—well above the standard deduction—resulting in a reduction of taxable income by $11,200. They complete Schedule A, transfer totals to Form 1040, mail the return, and include a money order with a payment plan request if needed. Filing now halts further penalties and reestablishes compliance.
Frequently Asked Questions (FAQs)
Can I still file my 2015 tax return?
Yes, you can still file your 2015 tax return at any time, even years after the original due date. However, if you were due a refund, the three-year claim window expired in April 2019, so the refund is forfeited. If you owe taxes, filing now stops new penalties and interest from accumulating and reestablishes compliance with the IRS.
Is it worth claiming itemized deductions for an old tax year?
Yes, if your qualified expenses—such as medical bills, property taxes, or donations—exceeded the 2015 standard deduction, itemized deductions can reduce taxable income. Always use the correct 2015 Schedule A and keep receipts or Form 1098 as proof. Itemizing may still lower your overall balance or limit additional interest and penalty charges.
What if I can’t pay the full amount I owe for 2015?
If you can’t pay in full, the IRS offers a payment plan that allows you to make monthly payments. Apply online or with Form 9465. Interest and minor penalties continue to accrue until paid. Still, enrollment prevents harsher collection actions, such as liens or levies, and demonstrates to the IRS that you’re attempting to resolve your tax balance responsibly.
Can I still deduct mortgage interest for 2015 if I file my tax return late?
Yes, you can deduct qualified mortgage interest paid in 2015 if you have Form 1098 or statements proving payment. The deduction applies only to eligible home loans under the 2015 limits. Always use that year’s Schedule A and instructions to ensure your amounts match what your lender reported to the IRS for accuracy.
How do I know if I need to file Schedule A as a self-employed taxpayer?
If you’re self-employed, business deductions belong on Schedule C, not Schedule A. However, you may still use Schedule A for personal deductions, such as mortgage interest, real estate taxes, or charitable contributions. Keep business and personal records separate to avoid confusion, disallowed deductions, or potential IRS audit questions about mixed expenses.
