$Missed Deductions

What is Schedule A and how do I fill it out step by step?

Standard vs Itemizedintermediate3 answers · 6 min readUpdated February 28, 2026

Quick Answer

Schedule A is the IRS form for claiming itemized deductions like mortgage interest, state taxes (up to $10,000), charitable donations, and medical expenses over 7.5% of AGI. You fill it out section by section, total your deductions, and enter the amount on Form 1040 line 12a—but only if it exceeds your standard deduction ($30,000 for married couples in 2026).

Best Answer

RK

Robert Kim, CPA

Best for taxpayers who need to understand Schedule A basics and step-by-step completion

Top Answer

What is Schedule A?


Schedule A (Form 1040) is the IRS form for claiming itemized deductions. According to IRS statistics, about 13.7% of taxpayers itemize, down from 30% before the Tax Cuts and Jobs Act increased standard deductions. Schedule A has five main sections where you report different types of deductible expenses.


Schedule A sections breakdown


Lines 1-4: Medical and Dental Expenses

  • Line 1: Enter total medical and dental expenses
  • Line 2: Enter your AGI from Form 1040
  • Line 3: Multiply line 2 by 7.5% (0.075)
  • Line 4: Subtract line 3 from line 1 (your deductible medical expenses)

  • Lines 5a-5f: State and Local Taxes (SALT)

  • Line 5a: State and local income taxes OR sales taxes (choose one)
  • Line 5b: State and local real estate taxes
  • Line 5c: State and local personal property taxes
  • Line 5d: Add lines 5a through 5c
  • Line 5e: Enter $10,000 ($5,000 if married filing separately)
  • Line 5f: Enter the smaller of line 5d or 5e (your SALT deduction)

  • Lines 6-7: Interest Expenses

  • Line 6: Home mortgage interest (from Form 1098)
  • Line 7: Investment interest (Form 4952 if over $0)

  • Lines 8-19: Charitable Donations

  • Lines 8-11: Cash contributions to qualified organizations
  • Lines 12-14: Other than cash contributions
  • Lines 15-16: Carryover contributions from prior years
  • Line 17: Total charitable contributions

  • Lines 20-21: Other Itemized Deductions

  • Currently limited due to Tax Cuts and Jobs Act suspensions

  • Step-by-step example: Completing Schedule A


    Let's complete Schedule A for a married couple with $150,000 AGI:


    Medical expenses:

  • Total medical expenses: $18,000
  • AGI threshold (7.5% × $150,000): $11,250
  • Deductible medical expenses: $18,000 - $11,250 = $6,750

  • State and local taxes:

  • State income taxes: $9,500
  • Property taxes: $8,500
  • Total SALT: $18,000
  • SALT deduction (capped): $10,000

  • Interest:

  • Mortgage interest: $22,000

  • Charitable donations:

  • Cash donations: $4,500

  • Schedule A calculation:


    Key rules and limitations


  • Medical expenses: Only amounts over 7.5% of AGI are deductible
  • SALT cap: Maximum $10,000 ($5,000 if married filing separately)
  • Mortgage interest: Limited to interest on $750,000 of acquisition debt
  • Charitable donations: Generally limited to 60% of AGI for cash contributions
  • 2% AGI floor eliminated: Miscellaneous deductions subject to 2% AGI floor are suspended through 2025

  • Common Schedule A mistakes to avoid


  • Not keeping receipts: Save all documentation for itemized deductions
  • Exceeding the SALT cap: Don't deduct more than $10,000 in state and local taxes
  • Including nondeductible expenses: Personal expenses, federal taxes, and penalties aren't deductible
  • Mixing cash and accrual methods: Use consistent accounting methods
  • Forgetting carryovers: Some charitable contributions can be carried forward

  • What you should do


    Before completing Schedule A, gather all relevant documents: mortgage interest statements (Form 1098), property tax bills, charitable donation receipts, and medical expense records. Calculate your total itemized deductions and compare to your standard deduction ($30,000 for married filing jointly in 2026). Only complete Schedule A if itemizing saves you money.


    Key takeaway: Schedule A has five main sections for medical expenses, taxes, interest, charity, and other deductions. Complete it only if your total itemized deductions exceed your standard deduction, and keep detailed records for all claimed expenses.

    Key Takeaway: Schedule A has five main sections for medical expenses, taxes, interest, charity, and other deductions. Complete it only if your total itemized deductions exceed your standard deduction, and keep detailed records for all claimed expenses.

    Schedule A line-by-line completion guide

    Schedule A SectionLinesWhat to IncludeCommon Limitations
    Medical & Dental1-4Expenses over 7.5% of AGIMust exceed 7.5% AGI threshold
    State & Local Taxes5a-5fIncome taxes, property taxes$10,000 cap ($5,000 MFS)
    Interest6-7Mortgage interest, investment interest$750,000 mortgage debt limit
    Charitable8-19Cash and property donations60% of AGI limit (cash)
    Other20-21Currently very limitedMost suspended 2018-2025

    More Perspectives

    RK

    Robert Kim, CPA

    Best for homeowners focusing on mortgage interest and property tax sections

    Schedule A for homeowners: Focus on lines 5-6


    As a homeowner, your biggest Schedule A deductions typically come from mortgage interest (line 6) and property taxes (line 5b). These two items alone often exceed the standard deduction.


    Line 6 - Home mortgage interest:

    Enter the amount from Box 1 of Form 1098 (Mortgage Interest Statement) that your lender sends you. This includes:

  • Interest on your primary mortgage
  • Interest on a second mortgage or home equity loan (if used to buy, build, or improve your home)
  • Points paid in the current year

  • Line 5b - Real estate taxes:

    Enter property taxes paid to state and local governments. Include:

  • Property taxes on your primary residence
  • Property taxes on vacation homes
  • Special assessments for local improvements (sewers, sidewalks)

  • Important homeowner limitations:

  • Mortgage interest is only deductible on up to $750,000 of acquisition debt
  • Property taxes are subject to the $10,000 SALT cap (combined with state income taxes)
  • Home equity loan interest is only deductible if proceeds improved your home

  • Example homeowner Schedule A:

  • Mortgage interest: $28,000
  • Property taxes: $12,000 (but limited by SALT cap)
  • State income taxes: $6,000
  • Total SALT deduction: $10,000 (capped)
  • Total key homeowner deductions: $38,000

  • This exceeds the $30,000 standard deduction by $8,000, saving approximately $1,760 in taxes (22% bracket).


    Key takeaway: Homeowners should focus on accurately reporting mortgage interest (line 6) and property taxes (line 5b), remembering that property taxes are subject to the $10,000 SALT cap.

    Key Takeaway: Homeowners should focus on accurately reporting mortgage interest (line 6) and property taxes (line 5b), remembering that property taxes are subject to the $10,000 SALT cap.

    RK

    Robert Kim, CPA

    Best for first-time Schedule A filers who need basic guidance

    Schedule A basics for first-time filers


    If you're new to itemizing, Schedule A can seem overwhelming with its 28 lines. The good news: most simple filers only need to complete a few key sections.


    Start with the big four categories:

    1. Medical expenses (lines 1-4): Only worthwhile if you had major medical bills over 7.5% of your income

    2. State and local taxes (lines 5a-5f): Include state income taxes and any property taxes

    3. Mortgage interest (line 6): From your Form 1098

    4. Charitable donations (lines 8-17): Cash donations to qualified charities


    Simple approach:

  • Add up your potential deductions in these four categories
  • If the total is less than your standard deduction, stop—take the standard deduction
  • If it's more, complete Schedule A line by line

  • Documentation you'll need:

  • Form 1098 (mortgage interest)
  • Property tax statements
  • State tax withholding from W-2 or estimated tax payment records
  • Charitable donation receipts
  • Medical expense receipts (if claiming)

  • Most common beginner mistake: Including expenses that aren't deductible, like:

  • Federal income taxes
  • Social Security and Medicare taxes
  • Traffic tickets and penalties
  • Personal living expenses
  • Life insurance premiums (usually)

  • Key takeaway: First-time Schedule A filers should focus on the four main categories: medical expenses over 7.5% of AGI, state/local taxes (capped at $10,000), mortgage interest, and charitable donations.

    Key Takeaway: First-time Schedule A filers should focus on the four main categories: medical expenses over 7.5% of AGI, state/local taxes (capped at $10,000), mortgage interest, and charitable donations.

    Sources

    schedule aitemized deductionsform 1040tax forms

    Reviewed by Robert Kim, CPA on February 28, 2026

    This content is for educational purposes only and is not a substitute for professional tax advice. Consult a qualified tax professional for advice specific to your situation.

    What is Schedule A? Step-by-Step Guide | MissedDeductions