2018 Instructions for Schedule A (Form 1040)
Checklist
Schedule A itemizes deductions for individuals claiming more deductible expenses than the standard deduction. The 2018 form reflects Tax Cuts and Jobs Act changes, including the suspension of miscellaneous itemized deductions subject to the 2%-of-AGI floor and limits on state and local tax deductions, distinguishing it from prior years. The TCJA suspended the deduction for miscellaneous itemized deductions under section 67 for 2018–2025.
Ten-Step Compliance Process
Step One: Documentation Assembly
Gather all documentation, including mortgage interest statements, charitable contribution receipts, state and local tax payment records, and casualty or theft loss documentation. Verify that charitable contributions meet the substantiation rules in Publication 526. Taxpayers must maintain organized records to support all itemized deductions claimed on the 2018 tax return.
Step Two: Medical and Dental Expenses
Complete Line 1 by reporting qualifying medical and dental expenses. Only expenses exceeding 7.5% of adjusted gross income are deductible per the 2018 rules. If claiming casualty or theft losses from a federally declared disaster, attach Form 4684 with required documentation. Taxpayers who received distributions from health savings accounts must see
Publication 969 to figure out their deduction.
Step Three: State and Local Taxes
Enter total SALT deduction on Line 2, but do not exceed the 2018 limit. This limitation is $10,000 for single, married filing jointly, head of household, and qualifying widow(er) filers. Married taxpayers filing separately face a lower limit of $5,000. State and local income taxes, sales taxes, and property taxes combine toward this cap under the Tax Cuts and Jobs Act provisions affecting income taxes paid at the state level.
Step Four: Home Mortgage Interest
Report mortgage interest paid in 2018 on qualified debt secured by a qualified residence per the
2018 rules on Line 5a. Attach Form 1098 or lender statement if required by instructions. The mortgage interest deduction applies only to debt used to buy, build, or substantially improve your home, with limits on qualifying debt amounts based on origination date.
Step Five: Charitable Contributions
Report cash and noncash charitable contributions per Publication 526 on Line 8. Noncash donations exceeding $500 require Form 8283, which must be attached to the return.
Contributions between $500 and $5,000 require Form 8283 Section A, while contributions over
$5,000 require Section B with qualified appraisal documentation. Taxpayers must maintain a contemporaneous written acknowledgment from a qualified organization for contributions of
$250 or more.
Step Six: Casualty and Theft Losses
Report losses on Line 16 only if they result from a federally declared disaster. Attach Form 4684 and document the loss with photographs, police reports, or insurance records. Personal casualty and theft losses not attributable to federally declared disasters are not deductible for
2018 through 2025 under TCJA provisions.
Step Seven: Standard Deduction Comparison
Verify that all itemized deductions on Schedule A exceed the 2018 standard deduction for your filing status before submitting. The standard deduction amounts are $12,000 for single and married filing separately, $24,000 for married filing jointly, and $18,000 for head of household. If your itemized deductions do not exceed these amounts, use the standard deduction instead to minimize taxable income on your income tax return.
Step Eight: Miscellaneous Deduction Verification
Confirm that miscellaneous itemized deductions such as unreimbursed employee expenses are not included on Schedule A for 2018, as they are suspended under TCJA. These deductions remain suspended through 2025. Taxpayers subject to the alternative minimum tax in prior years may see different tax outcomes due to this elimination affecting their income tax return calculations.
Step Nine: Form Attachment Requirements
Attach Form 8283 for noncash charitable contributions exceeding $500 with the appropriate section completed based on the contribution value. Attach a qualified appraiser declaration if required by Publication 526 for contributions over $5,000. Taxpayers claiming home mortgage interest must attach Form 1098 or equivalent documentation from lenders when preparing tax forms for submission to the Internal Revenue Service.
Step Ten: Form Assembly and Filing
Attach Schedule A to Form 1040 per assembly instructions and sign Form 1040 in the designated signature area. Schedule A does not have a separate signature block and requires only attachment to the primary return. See the IRS Where to File page for 2018 Form 1040 filing requirements and addresses based on your state of residence and refund status for the tax year.
Filing Eligibility Requirements
Nonresident aliens with income effectively connected to a U.S. trade or business may file
Schedule A using the nonresident alien version, Schedule A (Form 1040-NR). Individuals claiming the standard deduction cannot file Schedule A. Only U.S. citizens, resident aliens, and qualifying nonresident aliens with itemized deductions exceeding the standard deduction for their filing status may itemize income taxes and other qualifying expenses on this schedule.
TCJA Impact on Line Items
Miscellaneous Deductions Removed
Lines 7–15 previously allowed various miscellaneous deductions subject to the 2%-of-AGI floor, including unreimbursed employee expenses, investment fees, and tax preparation fees. This section was removed, and miscellaneous itemized deductions are suspended for 2018–2025 under TCJA. These deductions do not appear on the 2018 Schedule A form or other related tax forms provided by the Internal Revenue Service.
State and Local Tax Limitations
Line 2 previously allowed unlimited deductions for state and local income taxes, sales, and property taxes without restriction. The TCJA limited the SALT deduction to $10,000 per return for most filing statuses and $5,000 for married filing separately. This cap represents a significant
change affecting taxpayers in high-tax states who previously claimed larger deductions for income taxes paid to state and local governments during the tax year.
Tax Planning Considerations
Taxpayers near the itemized deduction threshold should evaluate timing strategies for deductible expenses, including the timing of income tax payments made through estimated payments. Bunching charitable contributions into alternate years or prepaying property taxes before assessment may optimize deductions on your income tax return for the applicable tax year. Consulting tax experts ensures compliance with evolving Internal Revenue Code provisions and maximizes available deductions under current tax rates and filing status requirements established by the Internal Revenue Service.
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