Comprehensive IRAC Legal Analysis of the 2025 Tax Year: Comparative Deduction Strategies for Senior Taxpayers under the One Big Beautiful Bill Act

This paper provides a comprehensive IRAC-based legal analysis of deduction optimization strategies for a 67-year-old single taxpayer with $155,000 in adjusted gross income (AGI) for the 2025 tax year under the One Big Beautiful Bill Act (OBBBA). The analysis evaluates the deductibility of $8,500 in medical expenses under Internal Revenue Code (IRC) §213, $9,500 in state and local taxes (SALT) under IRC §164 as modified by OBBBA, and the comparative benefit of itemizing deductions versus claiming the enhanced standard deduction available to taxpayers aged 65 and older. It further examines the newly enacted OBBBA Senior Bonus Deduction, including its income-based phase-out structure and its classification as a below-the-line deduction. Applying the statutory 7.5% AGI floor to medical expenses, the taxpayer is unable to deduct any portion of the $8,500 claimed because the threshold amount of $11,625 is not exceeded. Although the expanded $40,000 SALT cap permits full deductibility of the $9,500 in state and local taxes, total itemized deductions remain substantially lower than the $17,750 standard deduction available to a single filer over age 65. Consequently, electing the standard deduction yields a superior tax outcome. Additionally, the taxpayer qualifies for a partially phased-out Senior Bonus Deduction of $1,200, calculated under the 6% reduction rate applicable to income exceeding $75,000. The combined strategy of claiming the standard deduction and the Senior Bonus Deduction results in a total reduction of $18,950 in taxable income, lowering projected taxable income to $136,050. The findings demonstrate that, despite expanded SALT limits and targeted senior relief provisions, the elevated standard deduction continues to function as the dominant tax-minimization mechanism for many upper-middle-income senior taxpayers in 2025