12.1 Standard Deduction Baselines, Age 65/Blindness Additions & OBBBA Senior Bonus Deductions

Structural Function of the Standard Deduction

In individual federal income taxation, the standard deduction is a statutory base amount that reduces Adjusted Gross Income (AGI) to arrive at Taxable Income under IRC §63. Reported on Form 1040, Line 12e, it represents the minimum level of income that Congress shields from federal income taxation without requiring the taxpayer to substantiate specific personal expenses.

A taxpayer chooses annually between taking the applicable standard deduction or claiming itemized deductions on Schedule A (Form 1040). The vast majority of individual filers claim the standard deduction because it exceeds their allowable itemized expenditures. However, for the Enrolled Agent exam, you must master the exact statutory baseline amounts, additional deductions for age and blindness, the revolutionary OBBBA Senior Bonus Deduction, dependent deduction restrictions, and the specific statutory exceptions where claiming the standard deduction is completely prohibited.

Adjusted Gross Income (Form 1040, Line 11a)
  LESS: Standard Deduction OR Schedule A Itemized Deductions (Line 12e)
  LESS: Qualified Business Income (QBI) Deduction (Line 13a / IRC §199A)
  LESS: Schedule 1-A Deductions, including the $6,000 Senior Deduction (Line 13b)
EQUALS: Taxable Income (Form 1040, Line 15)

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2025 Baseline Standard Deduction Amounts (Post-OBBBA)

On July 4, 2025, the One Big Beautiful Bill Act (OBBBA) was signed into law, enacting retroactive adjustments to standard deduction baselines for the 2025 tax year. These statutory baselines replace the earlier Rev. Proc. 2024-40 inflation adjustments:

Permanent Zero Personal Exemption

Prior to 2018, taxpayers claimed personal and dependency exemptions under IRC §151 in addition to the standard deduction. The Tax Cuts and Jobs Act (TCJA) suspended personal exemptions to $0 through 2025. Under the OBBBA, Congress permanently eliminated personal exemptions ($0). Candidates should note that personal exemptions will not return; the expanded standard deduction and Child Tax Credit serve as the permanent statutory replacement.

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Additional Standard Deduction for Age 65 and Blindness (IRC §63(f))

Under IRC §63(f), taxpayers who are age 65 or older or legally blind receive an additional standard deduction amount that stacks directly on top of their baseline standard deduction.

Statutory Additional Amounts (2025 Tax Year)

• Unmarried Taxpayers (Single or Head of Household): $2,000 per qualifying condition.
• Married Taxpayers (MFJ, MFS, or QSS): $1,600 per qualifying condition per qualifying spouse.

Each qualifying condition is evaluated independently. A taxpayer who is both age 65 or older AND legally blind receives two additional amounts.

Critical Determination Rules

1. The Day-Before-Birthday Rule: Under federal tax law, an individual attains a given age on the day before the anniversary of their birth. Therefore, a taxpayer reaches age 65 on the day before their 65th birthday. For the 2025 tax year, an individual born on January 1, 1961, is legally treated as having reached age 65 on December 31, 2025, and is eligible for the additional standard deduction. The statutory test is whether the taxpayer was born before January 2, 1961.
2. Statutory Blindness Criteria: A taxpayer is considered blind under IRC §63(f)(4) if: (a) central visual acuity does not exceed 20/200 in the better eye with corrective lenses, or (b) the field of vision is restricted to a diameter of no greater than 20 degrees. If the taxpayer is not totally blind, an optometrist or ophthalmologist statement must be retained verifying these conditions.
3. Deceased Spouse Rule: If a spouse dies during the tax year after reaching age 65, the surviving spouse can claim the $1,600 additional standard deduction for the deceased spouse on a joint return. However, if the spouse died before their 65th birthday, no additional deduction is allowed, even if they would have reached age 65 later in the same calendar year.
4. No Additional Deduction for Dependents' Age/Blindness on Parent's Return: A taxpayer claiming an elderly parent as a dependent cannot take an additional standard deduction for the parent's age or blindness on the taxpayer's own Form 1040.

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The New OBBBA Senior Bonus Deduction (Tax Years 2025–2028)

A major feature of the One Big Beautiful Bill Act (OBBBA) is the enactment of the temporary Senior Bonus Deduction for tax years 2025 through 2028.

Core Statutory Mechanics

• Bonus Amount: $6,000 per qualifying individual who has attained age 65 before the close of the tax year.
• Joint Returns: On a Married Filing Jointly return where both spouses are age 65 or older, the potential bonus is $12,000 ($6,000 per spouse).
• Universal Availability: Unlike the regular age-65 additional standard deduction, the OBBBA Senior Bonus Deduction is available to BOTH standard deduction filers and Schedule A itemizers. It is not part of the standard deduction: it is figured in Part V of the new Schedule 1-A and entered on Form 1040, Line 13b, below the standard or itemized deduction on Line 12e.
• Eligibility Conditions: The qualifying individual must have a valid Social Security number and have been born before January 2, 1961 (for 2025), and a married taxpayer must file jointly to claim it.

MAGI Phaseout Thresholds & 6% Phaseout Rate

The Senior Bonus Deduction is targeted toward low- and middle-income seniors and is subject to a strict phaseout rate of 6% of Modified Adjusted Gross Income (MAGI) in excess of statutory thresholds:

$\text{Phaseout Reduction} = (\text{MAGI} - \text{Phaseout Floor}) \times 6\%$ $\text{Allowable Senior Bonus} = \text{Maximum Bonus (\$6,000 per person)} - \text{Phaseout Reduction}$

Phaseout Calculation Walkthrough: Evelyn, age 67, files as Single for 2025 with MAGI of $95,000.

1. Maximum Bonus: $6,000.
2. Excess MAGI: $95,000 - $75,000 = $20,000.
3. Phaseout Reduction: $20,000 \times 6% = $1,200.
4. Allowable Senior Bonus Deduction: $6,000 - $1,200 = $4,800.
5. Total Deductions from AGI: $17,750 standard deduction on Line 12e ($15,750 base + $2,000 age 65) plus the $4,800 senior deduction on Line 13b = $22,550.

Crucial Exam Trap: Taxpayers filing as Married Filing Separately (MFS) are statutorily ineligible for the OBBBA Senior Bonus Deduction, regardless of income level.

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Standard Deduction for Dependents (IRC §63(c)(5))

When an individual can be claimed as a dependent on another taxpayer's return (such as a child or elderly relative), their standard deduction on their own return is restricted to prevent income-shifting abuse.

The Dependent Deduction Formula (2025 Tax Year)

The basic standard deduction for a dependent is the GREATER of:

1. $1,350 (the statutory minimum dependent deduction for 2025); OR
2. Earned Income plus $450.

Statutory Ceiling: The calculated amount can never exceed the basic regular standard deduction for an unmarried single taxpayer ($15,750 for 2025).

$\text{Dependent Basic Standard Deduction} = \min\Big(\max(\$1,350, \, \text{Earned Income} + \$450), \, \$15,750\Big)$

Additional Standard Deduction for Dependent Age 65 or Blind

If the dependent is age 65 or older or legally blind, they add the full additional standard deduction amount ($2,000 for an unmarried dependent) on top of the calculated basic dependent deduction!

Example 1 (High Earned Income): Tyler, age 17, is claimed as a dependent by his parents. In 2025, Tyler earns $12,000 working at a grocery store and has $200 in bank interest. His earned income + $450 = $12,450. Because $12,450 is greater than $1,350 and less than $15,750, Tyler's standard deduction is $12,450.

Example 2 (Low Earned Income / Unearned Income): Chloe, age 20, is a college student claimed as a dependent. In 2025, she earns $600 from a campus job and receives $2,500 in taxable dividends. Her earned income + $450 = $1,050. Because $1,350 is greater than $1,050, Chloe's standard deduction is $1,350.

Example 3 (Elderly Dependent): Martha, age 72, is claimed as a dependent by her adult daughter. Martha has $800 in earned income from babysitting and $3,000 in pension income. Her basic dependent deduction is $1,350 (greater of $1,350 or $800 + $450 = $1,250). Because Martha is age 65 or older, she receives an additional standard deduction of $2,000. Her total standard deduction is $1,350 + $2,000 = $3,350.

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Taxpayers Ineligible for the Standard Deduction

Under IRC §63(c)(6), certain taxpayers are statutorily prohibited from claiming the standard deduction and have an allowable standard deduction of $0:

1. Married Filing Separately with Itemizing Spouse (Spousal Consistency Rule): Under IRC §63(c)(6)(A), if married individuals file separate returns and one spouse elects to itemize deductions on Schedule A, the other spouse cannot claim the standard deduction. The non-itemizing spouse must also itemize; if they have $0 in itemized deductions, their deduction is $0.
2. Nonresident Aliens (NRAs): Under IRC §63(c)(6)(B), a nonresident alien individual or dual-status alien during the year cannot claim the standard deduction. (Exception: An NRA married to a U.S. citizen or resident who makes an election under IRC §6013(g) or (h) to be treated as a resident alien may claim the standard deduction).
3. Short-Period Returns Due to Change in Accounting Period: Under IRC §63(c)(6)(C), an individual filing a return for a period of less than 12 months on account of a change in their annual accounting period under IRC §443(a)(1) is denied the standard deduction.
4. Estates, Trusts, and Partnerships: Fiduciary entities and passthroughs do not have standard deductions.

Exam Note: A short-period return caused by the death of a taxpayer does NOT lose the standard deduction. The full standard deduction is allowed on the final decedent return.