The standard deduction is a flat dollar amount that an individual who does not elect to itemize subtracts from adjusted gross income to reach taxable income. The Code builds it from two parts, a basic standard deduction fixed by filing status and an additional standard deduction for age 65 or blindness (26 U.S.C. 63(c)(1)). Taking it is the default position on a return, because itemizing is an affirmative election, and unless the individual makes that election no itemized deduction is allowed for the year at all (26 U.S.C. 63(e)).
For a taxable year beginning in 2025 the basic amount is $15,750 for a single filer or a married individual filing separately, $31,500 for a married couple filing jointly or a qualifying surviving spouse, and $23,625 for a head of household (IRS, Form 1040 (2025)).
On that return the figure sits at line 12e, which carries either the standard deduction or itemized deductions from Schedule A, and feeds the deduction total at line 14 (IRS, Form 1040 (2025)). It is not the only subtraction at that step, since the qualified business income deduction comes off whether the return itemizes or not, as QBI deduction sets out. Whether a client should take it or itemize is worked through in SALT deduction, and the rest of the chain down to the tax is in adjusted gross income and tax liability.
How the Basic Amount Is Set
The statute writes down only two amounts and builds the rest from them. The basic standard deduction is $4,400 for a head of household and $3,000 in any other case, and for a joint return or a surviving spouse it is 200 percent of that any-other-case amount, which is why the joint amount always lands at exactly twice the single amount (26 U.S.C. 63(c)(2)). A separate rule for years beginning after 2017 substitutes $23,625 for the $4,400 figure and $15,750 for the $3,000 figure (26 U.S.C. 63(c)(7)).
A married individual filing separately is never named in that list. That filer falls into the any-other-case category, which is the reason the separate amount and the single amount are the same number rather than a coincidence of rounding.
Indexing moved with the same rule. The general inflation adjustment no longer reaches those two figures, and instead they are increased for years beginning after 2025 by a cost-of-living adjustment measured from 2024, with any increase that is not a multiple of $50 rounded down to the next lowest multiple of $50 (26 U.S.C. 63(c)(7)(B)).
The Additional Amount for Age 65 or Blindness
The additional standard deduction is the sum of each additional amount the taxpayer is entitled to for age and for blindness, so a taxpayer who is both 65 and blind gets two of them (26 U.S.C. 63(c)(3)). The statutory figure is $600 for each qualifying condition, replaced by $750 for an individual who is not married and is not a surviving spouse, and both are indexed (26 U.S.C. 63(f)).
For 2025 the indexed amount is $1,600, rising to $2,000 if the taxpayer is also unmarried and not a surviving spouse (IRS, Topic no. 551).
Age is measured a day early. A person is considered 65 on the day before the 65th birthday, so the 2025 test is whether the taxpayer was born before January 2, 1961 (IRS, Publication 501 (2025)). On the return the claim is made by checking the age and blindness boxes at line 12d rather than by entering a number (IRS, Form 1040 (2025)).
Blindness is the one condition here that turns on a document rather than a date. A taxpayer who is not totally blind needs a certified statement from an eye doctor, an ophthalmologist or optometrist, saying that vision is no better than 20/200 in the better eye with glasses or contact lenses, or that the field of vision is 20 degrees or less, and the statement should include the fact that the condition is not likely to improve beyond those limits if that is so. The statement is kept in the taxpayer’s records rather than filed (IRS, Publication 501 (2025)).
A spouse’s amount does not require a joint return. The higher standard deduction is available for a spouse who is 65 or older or blind if the couple files jointly, or if they file separately and that spouse had no gross income and cannot be claimed as a dependent by another taxpayer (IRS, Publication 501 (2025)).
A final return follows its own rule. For a decedent the standard deduction is the same as it would have been had the decedent continued to live, but the higher amount for age cannot be claimed unless the decedent was 65 or older at the time of death (IRS, Publication 501 (2025)).
The Limit When Another Taxpayer Can Claim You
A dependent’s basic standard deduction is capped. It cannot exceed the greater of $500 or the sum of $250 and the individual’s earned income, both figures indexed (26 U.S.C. 63(c)(5)). For 2025 those become $1,350 and $450, and the result is then held down to the basic amount for the filing status (IRS, Publication 501 (2025)).
The word the statute uses is basic, and that one word does real work. The cap reaches the basic standard deduction only, so an additional amount for age or blindness is added after the cap rather than squeezed underneath it. The IRS worksheet runs in exactly that order, taking the smaller of the limited figure and the filing-status amount first, then adding $2,000 for each age or blindness box checked, or $1,600 each if the dependent is married (IRS, Publication 501 (2025)).
Say a single dependent, not blind and not yet 65, worked a summer job and had no other income for the year. The 2025 computation runs like this.
Earned income 2,600
Additional amount 450
Sum 3,050
Minimum standard deduction 1,350
Larger of the two 3,050
Single filing status amount 15,750
Standard deduction (smaller of the two) 3,050When the Standard Deduction Is Zero
Four categories are denied it outright. The standard deduction is zero for a married individual filing a separate return where either spouse itemizes deductions, for a nonresident alien individual, for an individual filing for a period of less than 12 months on account of a change in the annual accounting period, and for an estate or trust, common trust fund, or partnership, which makes the standard deduction an individual-return item and nothing else (26 U.S.C. 63(c)(6)).
The separate-return rule decides two returns at once. Because the deduction drops to zero when either spouse itemizes, a couple filing separately has to make the same choice on both returns or one of them ends up deducting nothing, and the form carries a box at line 12b for a filer whose spouse itemizes on a separate return (IRS, Form 1040 (2025)).
The short-period rule turns on the reason the year is short. It reaches a return covering less than 12 months because the annual accounting period changed, which is a different situation from a year cut short by a death (26 U.S.C. 63(c)(6)(C)).
The nonresident alien rule carries exceptions section 63 does not list. A nonresident alien married to a US citizen or resident alien at the end of the year who makes a joint election to be treated as a US resident for the whole year may take the standard deduction, and so may students and business apprentices who are residents of India and eligible for benefits under paragraph 2 of Article 21 of the United States-India income tax treaty (IRS, Topic no. 551). What the status itself means is in nonresident alien.
It Is Not the Enhanced Deduction for Seniors
Two different things sit under age 65 on a 2025 return and they are easy to merge. The additional standard deduction is part of the standard deduction itself (26 U.S.C. 63(c)(1)), while the enhanced deduction for seniors is a separate deduction of $6,000 for each qualified individual, allowed for taxable years beginning before January 1, 2029 (26 U.S.C. 151(d)(5)(C)). Publication 501 states the relationship in one line, that the senior deduction is in addition to the higher standard deduction for taxpayers age 65 or older (IRS, Publication 501 (2025)).
Four differences keep them apart. The additional standard deduction covers blindness as well as age, while a qualified individual for the senior deduction is only someone who has attained age 65 (26 U.S.C. 151(d)(5)(C)(ii)). The additional standard deduction has no income test, while the senior deduction is reduced once modified adjusted gross income passes a threshold (26 U.S.C. 151(d)(5)(C)(iii)). The additional standard deduction disappears the moment the return itemizes, while qualified individuals can claim the senior deduction whether they claim the standard deduction or itemize (IRS, Publication 501 (2025)). And the additional amount is claimed with a checkbox on Form 1040, while the senior deduction is figured on Schedule 1-A and arrives at line 13b (IRS, Form 1040 (2025)).
One exception does not carry across either. The special rules for residents of India who were students or business apprentices, which can open the standard deduction to a nonresident alien, do not apply to the enhanced deduction for seniors (IRS, Publication 501 (2025)). The rules governing the senior deduction on its own, including the thresholds and the Social Security number condition, are in what the One Big Beautiful Bill changed for accounting firms.
Common Questions
It is the basic amount for the filing status plus the additional amount for age. Take a single filer who is 65 or older, not blind, and not claimed as a dependent by anyone: the 2025 basic amount is $15,750 (IRS, Form 1040 (2025)) and the additional amount for an unmarried taxpayer who is not a surviving spouse is $2,000 (IRS, Topic no. 551).
Basic standard deduction, single 15,750
Additional amount for age 65, unmarried 2,000
Standard deduction 17,750The 2026 amounts are already published. For a taxable year beginning in 2026 the basic standard deduction is $32,200 for married individuals filing joint returns and surviving spouses, $24,150 for heads of households, and $16,100 for unmarried individuals and for married individuals filing separate returns (IRS, Rev. Proc. 2025-32).
The additional amount for the aged or the blind is $1,650 for 2026, increased to $2,050 if the individual is also unmarried and not a surviving spouse, and the dependent limitation holds at the greater of $1,350 or the sum of $450 and earned income (IRS, Rev. Proc. 2025-32).
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