Schedule A (Form 1040) + AI Agent Skill: Itemized Deductions Guide 2026

Hi, I'm Slava, CEO and co-founder of Jupid. Schedule A used to be the form most homeowners filed without thinking. Then TCJA capped SALT at $10,000, doubled the standard deduction, and overnight roughly 90% of filers stopped itemizing. Five years later, the One Big Beautiful Bill Act (OBBBA) of 2025 rewrote half the rules again — SALT is back up to $40,000 through 2029, mortgage insurance premiums are deductible again starting 2026, and charitable givers face a brand-new 0.5% AGI floor. The right answer for your 2025 return is different from the right answer for your 2024 return. This guide walks through every line of Schedule A as it stands for tax year 2026, plus the standard-vs-itemized math you actually need to run before you start filling boxes.

Official IRS resources: Schedule A (Form 1040) (PDF) · Instructions (PDF) · About Schedule A (Form 1040)

For most filers, Schedule A is a wasted hour. The standard deduction beats itemized by a wide margin, you write down $30,000 on Form 1040 Line 12, and move on. For homeowners in high-tax states with mortgages, large charitable givers, or filers with major medical bills, itemizing can be worth thousands.

The trick is knowing which group you're in before you start. This guide gives you the line-by-line rules, the 2026 limits, and a worked example showing exactly when itemizing pays and when it doesn't.

Standard vs Itemized: The Decision

Schedule A only matters if your itemized deductions exceed your standard deduction. If they don't, you take the standard deduction and skip Schedule A entirely.

The 2025 standard deduction (the return most readers are filing in early 2026):

Source: IRS Rev. Proc. 2024-40. The 2026 standard deduction is set by inflation adjustment and typically announced by the IRS in October 2025; verify against the current Revenue Procedure before filing.

The simple rule: add up everything on your Schedule A. If the total exceeds your standard deduction, itemize. If not, take the standard deduction.

A practical filter: if you don't own a home, don't live in a high-tax state, and don't give more than 5% of your income to charity, you almost certainly take the standard deduction. Itemizing pays mostly when you have a mortgage in a state with high property and income taxes.

What Schedule A Covers

Schedule A claims five categories of itemized deductions:

1. Medical and dental expenses — only the portion above 7.5% of AGI
2. Taxes paid (state and local income/sales tax, property tax) — capped under SALT rules
3. Interest paid — primarily home mortgage interest, plus investment interest
4. Gifts to charity — cash and non-cash, subject to AGI ceilings and (starting 2026) a 0.5% floor
5. Casualty and theft losses — restricted to federally declared disasters since TCJA

The total from Line 17 of Schedule A flows to Form 1040 Line 12 in place of the standard deduction.

Form: Schedule A (Form 1040). Instructions: Schedule A instructions.

Executive Summary: 2026 Key Numbers

The headline change for tax year 2026: the SALT cap quadrupled (from $10,000 to $40,400), making itemizing newly worthwhile for homeowners in high-tax states. The countervailing change: high-income charitable donors lose 0.5% of AGI off the top of their deduction.

For tax year 2025 (the return most readers are filing right now), the SALT cap is $40,000 — the OBBBA increase took effect retroactively for the 2025 tax year. Mortgage insurance premium deduction does NOT apply to 2025 returns; it starts with tax year 2026.

Lines 1-4 — Medical and Dental Expenses

Medical and dental expenses are deductible only to the extent they exceed 7.5% of your AGI. The 7.5% floor has been permanent since the Further Consolidated Appropriations Act of 2020 — earlier confusion about a 10% floor is no longer relevant.

Line 1 — Total qualified medical and dental expenses paid in the year (out of pocket; not reimbursed by insurance, HSA, FSA, or HRA).

Line 2 — AGI from Form 1040 Line 11.

Line 3 — 7.5% × Line 2.

Line 4 — Line 1 minus Line 3 (or zero if negative). This is your deductible medical expense.

What Qualifies (Pub 502)

• Doctor, dentist, surgeon, chiropractor, psychiatrist, and psychologist visits
• Prescription drugs and insulin (OTC drugs do NOT qualify unless prescribed)
• Long-term care services and qualified long-term care insurance premiums (age-based caps)
• Health insurance premiums (only if NOT already deducted as self-employed health insurance on Schedule 1 Line 17)
• Mental health treatment, dental, orthodontia, vision (glasses, contacts, LASIK), hearing aids
• Medical equipment (wheelchairs, crutches, prosthetics, monitors)
• Travel to and from medical care at the IRS medical mileage rate (21¢ per mile for 2025 per IRS Notice 2025-5; 2026 rate announced December 2025), plus parking and tolls
• Capital home improvements for medical reasons (e.g., wheelchair ramps) — only the portion that does NOT increase home value

What Does NOT Qualify

• Cosmetic surgery (unless correcting a deformity, congenital abnormality, or trauma injury)
• Gym memberships, general fitness, nutritional supplements (without prescription)
• Over-the-counter drugs without a prescription
• Funeral, burial, toiletries, cosmetics, maternity clothes
• Veterinary fees (except service-animal expenses)

Reference: IRC §213; IRS Publication 502.

Lines 5-7 — Taxes You Paid (SALT)

This is the section that changed most dramatically in 2025. The SALT cap was $10,000 from 2018-2024. The OBBBA raised it to $40,000 for 2025, $40,400 for 2026, with 1% annual increases through 2029, before reverting to $10,000 in 2030.

Line 5a — State and local income taxes OR general sales taxes (pick the higher one). Sales tax is the better choice for filers in states with no income tax (Florida, Texas, Tennessee, Washington, Wyoming, Alaska, South Dakota, Nevada). Use the IRS Sales Tax Deduction Calculator or the optional sales tax tables in the Schedule A instructions.

Line 5b — State and local real estate taxes (your property tax bill). Only the amounts assessed at a uniform rate based on the property's value qualify. Special assessments for local improvements (sidewalks, sewers) typically don't.

Line 5c — State and local personal property taxes — taxes based on the value of personal property (often vehicle registration fees, where part of the fee is value-based). Flat fees don't count.

Line 5d — Sum of 5a + 5b + 5c.

Line 5e — Smaller of Line 5d or the SALT cap. For tax year 2025, the cap is $40,000 ($20,000 MFS). For 2026, $40,400 ($20,200 MFS). If your modified AGI exceeds $500,000, the cap is reduced by 30% of the excess MAGI but not below $10,000.

Line 6 — Other taxes. The most common entry is foreign income tax — though most filers do better claiming the foreign tax credit on Schedule 3 Line 1 instead.

Line 7 — Sum of Line 5e + Line 6. Total taxes deduction.

SALT Phaseout for High Earners

Starting tax year 2025, if your MAGI exceeds $500,000 ($250,000 MFS), the $40,000 cap phases down by 30 cents per dollar of excess MAGI, with a hard floor of $10,000. Worked at $550,000 MAGI: excess $50,000, phaseout $15,000, cap = $40,000 − $15,000 = $25,000. At $700,000 MAGI: phaseout would zero the cap, so the $10,000 floor applies. The income threshold and floor both increase 1% annually through 2029.

Reference: IRC §164(b)(6) as amended by OBBBA 2025; Bipartisan Policy Center summary.

Lines 8-10 — Interest You Paid

Mortgage interest is the largest itemized deduction for most homeowners. The rules below apply to qualified residence interest on your main home and one second home.

Line 8a — Home mortgage interest and points reported to you on Form 1098 (the annual statement your lender sends).

Line 8b — Home mortgage interest NOT reported on Form 1098. The most common case: seller-financed mortgages where the lender is an individual, not a financial institution. You must list the seller's name, address, and SSN/EIN.

Line 8c — Points NOT reported on Form 1098. Points paid to obtain a mortgage are generally deductible over the life of the loan, but points paid on the purchase of your main home can sometimes be deducted in full in the year paid (Pub 936 details the requirements). Points paid on a refinance are spread over the life of the new loan unless used for home improvements.

Line 8d — Mortgage insurance premiums. This deduction was eliminated after 2021 and reinstated permanently by OBBBA — but only beginning tax year 2026. For 2025 returns, leave Line 8d blank. Starting 2026, premiums for private mortgage insurance (PMI) and FHA/VA/RHS mortgage insurance qualify, with a phaseout that reduces the deduction by 10% for every $1,000 of MAGI above $100,000 ($50,000 MFS).

Line 8e — Sum of 8a + 8b + 8c + 8d.

Line 9 — Investment interest expense (interest on loans used to buy taxable investments). Limited to net investment income; complete Form 4952 to compute.

Line 10 — Sum of Line 8e + Line 9. Total interest deduction.

Acquisition Debt Cap: $750,000 (or $1,000,000 Grandfathered)

Mortgage interest is deductible only on acquisition indebtedness — debt used to buy, build, or substantially improve your main home or second home — up to a debt cap.

• Mortgages originated after December 15, 2017: $750,000 cap ($375,000 MFS)
• Mortgages originated on or before December 15, 2017: $1,000,000 cap ($500,000 MFS) — grandfathered

OBBBA made the $750,000 cap permanent. Before OBBBA, the cap was scheduled to revert to $1,000,000 after 2025.

If your loan exceeds the cap, only the portion of interest attributable to the first $750,000 (or $1,000,000) of debt is deductible. Pub 936 walks through the computation.

HELOC Interest

Interest on a home equity line of credit (HELOC) or home equity loan is deductible only if the loan proceeds were used to buy, build, or substantially improve the home that secures the loan. HELOCs used to pay off credit cards, fund a vacation, or buy a car are NOT deductible. This restriction has been in place since TCJA and was made permanent by OBBBA.

Refinance Mortgages

When you refinance, the new mortgage retains its acquisition-debt status up to the principal balance of the old loan at the time of refinancing. Any cash-out portion is subject to the same use-test as a HELOC: deductible only if used for home improvements.

Reference: IRC §163(h); IRS Publication 936.

Lines 11-14 — Gifts to Charity

Charitable contributions to qualified 501(c)(3) organizations are deductible — but starting tax year 2026, only the portion above 0.5% of AGI counts.

Line 11 — Cash contributions (checks, credit-card charges, electronic transfers, payroll deductions). 60% of AGI ceiling.

Line 12 — Non-cash contributions (clothing, household goods, appreciated stock, real estate, vehicles). 30% of AGI ceiling for most non-cash gifts; 20% for gifts of appreciated property to certain private foundations.

Line 13 — Carryover from prior year. Contributions exceeding the AGI ceiling carry forward five years.

Line 14 — Total. Starting 2026, subtract 0.5% of AGI from this total before entering on Schedule A — only the excess is deductible.

The New 0.5% AGI Floor (Tax Year 2026+)

OBBBA introduced a 0.5% AGI floor on itemized charitable contributions, effective tax year 2026. Mechanics:

• Compute total charitable contributions (Lines 11 + 12 + 13).
• Subtract 0.5% × AGI.
• The remainder is what flows to Schedule A as your charitable deduction.

Example. AGI $200,000, total charitable contributions $5,000. Floor = $200,000 × 0.5% = $1,000. Deductible portion = $5,000 − $1,000 = $4,000.

Important: the 0.5% floor does NOT apply to tax year 2025 returns. Contributions made in 2025 retain full deductibility (subject only to the AGI ceilings). This is why end-of-2025 charitable giving was widely encouraged as a planning move.

Substantiation Rules

• Single gift under $250: bank record or written acknowledgment.
• Single gift $250 or more: contemporaneous written acknowledgment from the charity stating the amount and whether goods/services were provided in return.
• Non-cash gifts over $500: Form 8283 Section A.
• Non-cash gifts over $5,000: Form 8283 Section B + qualified appraisal (not required for publicly traded securities).
• Donated vehicles: Form 1098-C from the charity within 30 days; deduction limited to gross proceeds unless the charity uses the vehicle.

QCDs Are NOT on Schedule A

If you're 70½+ and direct an IRA distribution to a charity (a Qualified Charitable Distribution), the amount is excluded from gross income on Form 1040 Line 4b — it does NOT go on Schedule A. QCDs lower AGI directly and don't require itemizing. Up to $108,000 per person allowed for 2025.

Reference: IRC §170; IRS Publication 526; IRC §170(p) (new 0.5% floor under OBBBA 2025).

Line 15 — Casualty and Theft Losses

Since TCJA, personal casualty and theft losses on Schedule A are deductible only if the loss is attributable to a federally declared disaster. This restriction is in place through 2025 and was made permanent by OBBBA.

What qualifies:

• Loss of property in a federally declared disaster zone (hurricanes, wildfires, floods, tornadoes that triggered a FEMA major-disaster or emergency declaration)
• Verify your disaster qualifies at FEMA Disaster Declarations

The computation:

1. Loss = lesser of (a) decrease in fair market value, or (b) adjusted basis
2. Subtract any insurance reimbursement
3. Subtract $100 per casualty event
4. Sum all casualties and subtract 10% of AGI
5. The remainder goes on Line 15

Form 4684 (Casualties and Thefts) is required. Theft losses unrelated to a federally declared disaster are NOT deductible on Schedule A as a personal loss; they may still qualify as a business loss on Schedule C if the property was business-use.

Reference: IRC §165(h); IRS Publication 547.

Line 16 — Other Itemized Deductions

A short list of items that survived TCJA's elimination of the 2%-floor miscellaneous deductions:

• Gambling losses — only up to gambling winnings reported on Schedule 1 Line 8b. Keep a gambling diary plus W-2G forms.
• Casualty/theft losses on income-producing property (e.g., rental property) — still deductible despite the disaster-only restriction on personal property
• Federal estate tax on income in respect of a decedent (IRD)
• Amortizable bond premium on taxable bonds
• Repayment of amounts under a claim of right (over $3,000)
• Unrecovered investment in a pension when annuity ends before basis recovery
• Impairment-related work expenses for disabled employees

Unreimbursed employee business expenses, tax prep fees, and investment advisory fees remain non-deductible (made permanent by OBBBA).

Line 17 — Total Itemized Deductions

Sum Lines 4 + 7 + 10 + 14 + 15 + 16. The total flows to Form 1040 Line 12 in place of the standard deduction.

If Line 17 is less than your standard deduction, take the standard deduction instead and skip Schedule A.

Worked Example: Patricia and Mike, MFJ Homeowners in California

Patricia and Mike file jointly. They own a home in San Diego, give to their church, and had a moderate medical year. Their tax year 2025 numbers:

• AGI: $180,000
• Mortgage interest (Form 1098): $11,800
• Property taxes paid: $9,500
• California state income tax withheld: $14,000
• Cash charitable contributions to their church: $4,200
• Total medical expenses (out of pocket, after insurance): $14,700

Line 1-4: Medical

Line 1: Total medical expenses          $14,700
Line 2: AGI                            $180,000
Line 3: 7.5% of AGI                     $13,500
Line 4: Deductible medical              $1,200

Line 5-7: SALT

Line 5a: State income tax              $14,000
Line 5b: Real estate taxes              $9,500
Line 5c: Personal property taxes            $0
Line 5d: Sum                           $23,500
Line 5e: Capped at SALT limit          $23,500   (under $40,000 cap; full amount deducts)
Line 6:  Other taxes                        $0
Line 7:  Total taxes                   $23,500

Note: Pre-OBBBA (under the $10,000 SALT cap), Patricia and Mike would have lost $13,500 of this deduction. The OBBBA cap increase saved them roughly $3,000 in federal tax at their 22% bracket.

Line 8-10: Interest

Line 8a: Mortgage interest (Form 1098) $11,800
Line 8b: Mortgage interest not on 1098      $0
Line 8c: Points not on 1098                 $0
Line 8d: Mortgage insurance premiums        $0   (deduction starts tax year 2026)
Line 8e: Sum                           $11,800
Line 9:  Investment interest                $0
Line 10: Total interest                $11,800

Line 11-14: Charity

Line 11: Cash contributions             $4,200
Line 12: Non-cash contributions             $0
Line 13: Carryover from prior year          $0
Line 14: Total charitable               $4,200

For 2025, no 0.5% floor applies — full $4,200 deducts.

Line 15-16: Other

Line 15: Casualty losses                    $0
Line 16: Other deductions                   $0

Line 17: Total Itemized

Line 4:  $1,200
Line 7:  $23,500
Line 10: $11,800
Line 14: $4,200
Line 15: $0
Line 16: $0
─────────────────
Line 17: $40,700

Compare to standard deduction MFJ 2025: $30,000.

Itemized total $40,700 exceeds standard deduction by $10,700. Patricia and Mike itemize, gaining $10,700 of additional deductions worth approximately $2,354 in federal tax savings at their 22% bracket.

Sensitivity Check

If Patricia and Mike move to Texas (no state income tax), Line 5a drops to roughly $1,200 (state sales tax via the optional table). Line 17 falls to $27,900 — below the $30,000 standard deduction. They take the standard deduction. The lesson: SALT is what makes itemizing pay for typical homeowners.

For tax year 2026, two OBBBA changes shift the math: PMI becomes deductible on Line 8d (if they pay it), and a 0.5% AGI charity floor of $900 reduces their charitable deduction. Itemizing still wins, but high-income donors lose meaningful deduction value to the new floor.

Common Mistakes to Avoid

Mistake #1: Itemizing When the Standard Deduction Is Higher

Problem: Filling out Schedule A out of habit without comparing to the standard deduction. Solution: Always run both numbers. Write the standard deduction next to Schedule A Line 17 and compare.

Mistake #2: Forgetting the SALT Cap (or Using the Wrong One)

Problem: Using the old $10,000 cap on a 2025 return, or skipping SALT tracking entirely. Solution: For 2025 and 2026 returns, the cap is $40,000 / $40,400. Track your full state and local tax payments — the cap applies at Line 5e.

Mistake #3: Deducting Cosmetic Surgery as Medical

Problem: Counting elective cosmetic procedures, gym memberships, or wellness purchases as medical expenses. Solution: Pub 502 has the specific list. If a procedure is purely elective (not deformity, congenital abnormality, or trauma), it doesn't qualify. When in doubt, get a doctor's letter establishing medical necessity.

Mistake #4: Missing Substantiation for Charitable Gifts ≥ $250

Problem: Claiming a $500 gift with only the canceled check, no written acknowledgment. Solution: Keep every charity acknowledgment letter. Most charities send year-end statements automatically; if yours doesn't, request one before you file.

Mistake #5: Treating Commuting Miles as Medical Transportation

Problem: Counting commute to a job at a hospital as medical mileage because medical appointments happen there. Solution: Medical mileage is only for trips primarily for medical care. Commuting is never deductible. Keep a separate log for medical trips with date, destination, and reason.

How Jupid Helps with Itemized Deductions

Tracking the inputs to Schedule A is the hard part. Most filers reach April with a folder of mortgage statements, a few charity acknowledgments, and a fuzzy memory of medical spending — then spend a weekend reconstructing the year.

Jupid's AI accountant (in WhatsApp/iMessage and the web app) categorizes every transaction from your connected accounts in real time at 95.9% accuracy. We separate property tax from mortgage escrow, mortgage interest from principal and PMI, medical payments by provider type, charitable contributions by payee, and state/local tax payments.

By April you have a clean Schedule A worksheet — every line populated, every receipt stored. Year-round, you can ask "should I be itemizing this year?" and get an answer that updates as the year progresses.

The rules engine is OBBBA-aware: 2025/2026 SALT cap at $40,000/$40,400, PMI deductible starting 2026, the new 0.5% charity floor for 2026. We update the rules whenever IRS guidance shifts so you don't have to read Revenue Procedures.

Try Jupid →

Action Checklist

Before You Start

• Pull AGI from Form 1040 Line 11
• Decide whether you're filing for tax year 2025 or 2026 (different rules apply)
• Compare your estimated itemized total against your standard deduction — only itemize if you'll exceed it

Gather Documents

• Form 1098 (mortgage interest from each lender)
• Property tax bill(s)
• State income tax withholding (W-2 box 17, 1099 boxes, estimated tax payment records)
• Medical expense log + receipts + EOBs from insurance
• Charitable contribution acknowledgments (every gift ≥ $250 requires a written letter)
• Form 4684 (if claiming federally declared disaster losses)
• Form 8283 (if non-cash gifts > $500)

Fill in Schedule A

• Lines 1-4: Medical with 7.5% AGI floor applied
• Lines 5-7: SALT capped at $40,000 / $40,400 (or phased down if MAGI > $500K)
• Lines 8-10: Mortgage interest within acquisition-debt cap; PMI on Line 8d only for tax year 2026+
• Lines 11-14: Charity with 0.5% AGI floor applied (2026+ only)
• Line 15: Casualty losses only if federally declared disaster
• Line 16: Other (gambling losses up to winnings, etc.)
• Line 17: Total — compare to standard deduction one more time before filing

Verify

• Line 17 > standard deduction (otherwise take standard and skip Schedule A)
• All mortgage interest on Line 8a ties to Form 1098
• SALT cap correctly applied at Line 5e
• Form 8283 attached if non-cash charity > $500
• Form 4684 attached if casualty/theft

Resources and Citations

IRS Forms and Instructions

• Schedule A (Form 1040) — the form
• Instructions for Schedule A — line-by-line IRS guidance
• Form 4684 — Casualties and Thefts
• Form 4952 — Investment Interest Expense Deduction
• Form 8283 — Noncash Charitable Contributions

IRS Publications

• Publication 17 — Your Federal Income Tax (For Individuals)
• Publication 502 — Medical and Dental Expenses
• Publication 526 — Charitable Contributions
• Publication 530 — Tax Information for Homeowners
• Publication 547 — Casualties, Disasters, and Thefts
• Publication 936 — Home Mortgage Interest Deduction

Tax Code References

• IRC §63 — Standard deduction
• IRC §163(h) — Mortgage and investment interest, including the $750,000 acquisition debt cap (made permanent by OBBBA 2025)
• IRC §164(b)(6) — SALT deduction cap, raised to $40,000 (2025) / $40,400 (2026) by OBBBA 2025
• IRC §165(h) — Casualty losses, restricted to federally declared disasters by TCJA
• IRC §170 — Charitable contributions; new 0.5% AGI floor at IRC §170(p) (effective 2026 under OBBBA)
• IRC §213 — Medical and dental expenses, 7.5% AGI floor
• Rev. Proc. 2024-40 — 2025 inflation adjustments (standard deduction, mileage, etc.)

2026 Key Numbers Summary

Final Thoughts

Schedule A is back in play for many homeowners after OBBBA. If you live in a high-tax state (California, New York, New Jersey, Connecticut, Massachusetts, etc.) with combined property and income taxes pushing past $20,000 and you have a mortgage, itemizing is likely the right answer for tax year 2025.

The key strategies:

1. Run both numbers — Schedule A total vs standard deduction every year.
2. Bunch deductions when on the edge — accelerating two years of charity into one (or prepaying property taxes) can push you past the standard.
3. Track substantiation in real time — year-end scrambles are how $250+ charity gifts lose their deduction.
4. Watch the 2026 charity floor — high-income donors who can frontload into 2025 retain full deductibility.

Schedule A rewards filers who keep records, not filers who guess.

Use This with Your AI Agent

If you're using Claude, ChatGPT, or another AI agent to help fill out Schedule A (Form 1040), we've published an open-source skill that gives the agent exact line-by-line instructions, validation checks, ask-don't-guess prompts, and worked examples — the same logic Jupid uses internally.

→ jupid-tax/jupid-skills on GitHub — forms/schedule-a/

For Claude Code: cp -r jupid-skills/forms/schedule-a ~/.claude/skills/. For the Anthropic SDK, load SKILL.md into the system prompt and the references/ files on demand. For browser-automation runtimes, filing.md covers the e-file or paper-file workflow.

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Disclaimer

This article provides general information about itemized deductions and should not be considered tax advice. Tax laws change frequently — OBBBA 2025 alone changed five Schedule A rules — and individual circumstances vary significantly. The 2026 standard deduction and several inflation-adjusted figures referenced in this article are subject to IRS announcement (typically October 2025); verify against the current Revenue Procedure before filing. For advice specific to your situation, consult with a qualified tax professional.

Tax Year: 2026 (with 2025 return rules where indicated) Last Updated: April 28, 2026