Standard vs itemized deduction: how to choose
Every individual return subtracts either the standard deduction or itemized deductions from adjusted gross income, never both. The decision rule: compute both and use the larger, unless the taxpayer is not allowed the standard deduction at all, in which case itemizing is the only option. This guide uses tax year 2025, with figures from IRS Publication 501 (2025) and the 2025 Instructions for Schedule A. It is exam preparation, not tax advice.
Four questions, in this order
| Question | If yes | Source |
|---|---|---|
| 1. Is the taxpayer barred from the standard deduction? | The standard deduction is zero, so itemize. The bars: married filing separately when the spouse itemizes, a short tax year from a change of accounting period, and a nonresident or dual-status alien (unless the alien spouse election is made) | Pub. 501 |
| 2. Can someone else claim the taxpayer as a dependent? | A limited amount applies, not the table amount | Pub. 501 |
| 3. Is the taxpayer 65 or older, or blind? | Add the extra amount | Pub. 501 |
| 4. Do itemized deductions beat the result? | Itemize, using Schedule A | Pub. 501 |
The 2025 amounts
| Filing status | Basic standard deduction, 2025 |
|---|---|
| Single | $15,750 |
| Married filing separately | $15,750 |
| Married filing jointly or qualifying surviving spouse | $31,500 |
| Head of household | $23,625 |
For a taxpayer born before January 2, 1961, or who is blind, Pub. 501 Table 7 adds to these. Examples taken from the publication: a joint couple with one blind spouse has $33,100, and a joint couple both over 65 has $34,700. A single filer with one box checked has $17,750.
A person who can be claimed as a dependent gets the larger of $1,350 or earned income plus $450, capped at the regular amount (Pub. 501, Table 8). A dependent teenager with $3,000 of wages has $3,450, not $15,750.
Separate from both methods, Pub. 501 describes an enhanced deduction for seniors beginning in 2025, with a maximum of $6,000 ($12,000 if married filing jointly and both spouses are eligible). The Schedule A instructions say it is claimed on Schedule 1-A, so a taxpayer can have it whether or not they itemize. It does not change the comparison above.
Itemized deductions: the limits that carry 2025 questions
Schedule A instructions for 2025 list the categories and limits.
- Medical and dental: only the part above 7.5% of adjusted gross income.
- State and local taxes (SALT): generally limited to $40,000 ($20,000 if married filing separately) for 2025. The limit is reduced when modified adjusted gross income exceeds $500,000 ($250,000 married filing separately), by 30% of the excess, but not below $10,000 ($5,000 if married filing separately).
- Home mortgage interest: for debt taken out after December 15, 2017, interest on up to $750,000 of debt ($375,000 if married filing separately).
- Personal casualty and theft losses: only if attributable to a federally declared disaster, and only the part of each loss above $100 and the total above 10% of AGI.
- Charitable gifts, investment interest and other items have their own limits; see Pub. 526 and Pub. 550.
A worked comparison
A single, 40-year-old taxpayer has 2025 AGI of $60,000. Paid items: state income tax $9,000, property tax $5,000, mortgage interest $6,000 (well under the debt limit), cash gifts to charity $2,500 and unreimbursed medical costs $5,000.
- Medical floor: 7.5% of $60,000 = $4,500, so $500 counts.
- Taxes: $9,000 + $5,000 = $14,000, under the $40,000 cap.
- Total itemized: $14,000 + $6,000 + $2,500 + $500 = $23,000.
- Standard deduction: $15,750.
Itemizing is larger by $7,250. If the property tax were $1,000, taxes would be $10,000, total itemized $19,000, still higher. Cut the mortgage interest to $0 and the total is $13,000, so the standard deduction wins. Pub. 501 also notes a taxpayer may choose to itemize even when it is smaller, for example to get a better result on a state return.
Which exams test this
| Exam | How the topic appears | Where on this site |
|---|---|---|
| SEE Part 1 | Domain 3, Deductions and Credits (17 scored questions): itemized deductions (medical, taxes, interest, charitable, casualty and theft, other, and the Form 1040-NR list), which feeds the standard-or-itemize choice | Deductions and credits explained |
| SEE Part 1 | Domain 1, Preliminary Work and Taxpayer Data (14): sources of applicable deductions, itemized or standard, when gathering client data | Preliminary work explained |
| SEE Part 1 | Domain 5, Advising the Individual Taxpayer (11): planning with deductions and the timing of expenses | Advising individuals explained |
Part 2 and Part 3 list no standard-or-itemized objective.
How exam questions are built
- The spouse trap. A married person filing separately has a zero standard deduction when the spouse itemizes, so both must itemize. Head of household filers are not caught by this rule.
- Age and blindness boxes. The question gives a birth date. Born on January 1, 1961 or earlier counts as 65 for 2025, because a person is treated as 65 the day before the birthday.
- Dependent filers. A “student claimed by parents” almost always means the Table 8 formula.
- Thresholds applied to the wrong base. Medical uses AGI, not taxable income, and applies only above 7.5%.
- Planning questions. Lumping deductions into one year can push itemized above the standard deduction. This ties to filing status, which sets the standard deduction, and to capital gains and losses when losses or gains change AGI.
Practice questions
Question 1. For 2025, Nadia and Paul are married and file separately. Paul itemizes deductions. Nadia has $9,000 of deductible items. What is Nadia's position?
- A. She takes the $15,750 standard deduction
- B. She takes the $31,500 standard deduction
- C. She takes the $23,625 standard deduction
- D. She must itemize, so her deduction is $9,000
Show answer
Answer: D
When one spouse who files separately itemizes, the other spouse cannot take the standard deduction, so the standard deduction is zero and Nadia must itemize, using her $9,000. Taking $15,750 is the basic amount for a separate filer who may claim it, $31,500 is the joint amount and $23,625 is head of household, none of which applies.
Question 2. In 2025, a single taxpayer (age 40) has AGI of $80,000, state income and property taxes of $11,000, mortgage interest of $5,000 and charitable gifts of $1,000. There are no other itemizable items. Which is correct?
- A. Itemize, because $17,000 exceeds $15,750
- B. Take the standard deduction, because it is always larger
- C. Take the standard deduction, because itemized deductions are limited to $15,000
- D. Take the $23,625 standard deduction
Show answer
Answer: A
Itemized deductions are $11,000 + $5,000 + $1,000 = $17,000, which exceeds the $15,750 single standard deduction, so itemizing is better by $1,250. The SALT total is under the $40,000 cap and no medical floor applies because there are no medical costs. Taking the standard deduction leaves $1,250 on the table, and the other options use wrong amounts.