26 U.S.C. § 63 : US Code - Section 63: Taxable income defined

    (a) In general
      Except as provided in subsection (b), for purposes of this
    subtitle, the term "taxable income" means gross income minus the
    deductions allowed by this chapter (other than the standard
    deduction).
    (b) Individuals who do not itemize their deductions
      In the case of an individual who does not elect to itemize his
    deductions for the taxable year, for purposes of this subtitle, the
    term "taxable income" means adjusted gross income, minus - 
        (1) the standard deduction, and
        (2) the deduction for personal exemptions provided in section
      151.
    (c) Standard deduction
      For purposes of this subtitle - 
      (1) In general
        Except as otherwise provided in this subsection, the term
      "standard deduction" means the sum of - 
          (A) the basic standard deduction,
          (B) the additional standard deduction,
          (C) in the case of any taxable year beginning in 2008 or
        2009, the real property tax deduction,
          (D) the disaster loss deduction, and
          (E) the motor vehicle sales tax deduction.
      (2) Basic standard deduction
        For purposes of paragraph (1), the basic standard deduction is -
       
          (A) 200 percent of the dollar amount in effect under
        subparagraph (C) for the taxable year in the case of - 
            (i) a joint return, or
            (ii) a surviving spouse (as defined in section 2(a)),

          (B) $4,400 in the case of a head of household (as defined in
        section 2(b)), or
          (C) $3,000 in any other case.
      (3) Additional standard deduction for aged and blind
        For purposes of paragraph (1), the additional standard
      deduction is the sum of each additional amount to which the
      taxpayer is entitled under subsection (f).
      (4) Adjustments for inflation
        In the case of any taxable year beginning in a calendar year
      after 1988, each dollar amount contained in paragraph (2)(B),
      (2)(C), or (5) or subsection (f) shall be increased by an amount
      equal to - 
          (A) such dollar amount, multiplied by
          (B) the cost-of-living adjustment determined under section
        1(f)(3) for the calendar year in which the taxable year begins,
        by substituting for "calendar year 1992" in subparagraph (B)
        thereof - 
            (i) "calendar year 1987" in the case of the dollar amounts
          contained in paragraph (2)(B), (2)(C), or (5)(A) or
          subsection (f), and
            (ii) "calendar year 1997" in the case of the dollar amount
          contained in paragraph (5)(B).
      (5) Limitation on basic standard deduction in the case of certain
        dependents
        In the case of an individual with respect to whom a deduction
      under section 151 is allowable to another taxpayer for a taxable
      year beginning in the calendar year in which the individual's
      taxable year begins, the basic standard deduction applicable to
      such individual for such individual's taxable year shall not
      exceed the greater of - 
          (A) $500, or
          (B) the sum of $250 and such individual's earned income.
      (6) Certain individuals, etc., not eligible for standard
        deduction
        In the case of - 
          (A) a married individual filing a separate return where
        either spouse itemizes deductions,
          (B) a nonresident alien individual,
          (C) an individual making a return under section 443(a)(1) for
        a period of less than 12 months on account of a change in his
        annual accounting period, or
          (D) an estate or trust, common trust fund, or partnership,

      the standard deduction shall be zero.
      (7) Real property tax deduction
        For purposes of paragraph (1), the real property tax deduction
      is the lesser of - 
          (A) the amount allowable as a deduction under this chapter
        for State and local taxes described in section 164(a)(1), or
          (B) $500 ($1,000 in the case of a joint return).

      Any taxes taken into account under section 62(a) shall not be
      taken into account under this paragraph.
      (8) Disaster loss deduction
        For the purposes of paragraph (1), the term "disaster loss
      deduction" means the net disaster loss (as defined in section
      165(h)(3)(B)).
      (9) Motor vehicle sales tax deduction
        For purposes of paragraph (1), the term "motor vehicle sales
      tax deduction" means the amount allowable as a deduction under
      section 164(a)(6). Such term shall not include any amount taken
      into account under section 62(a).
    (d) Itemized deductions
      For purposes of this subtitle, the term "itemized deductions"
    means the deductions allowable under this chapter other than - 
        (1) the deductions allowable in arriving at adjusted gross
      income, and
        (2) the deduction for personal exemptions provided by section
      151.
    (e) Election to itemize
      (1) In general
        Unless an individual makes an election under this subsection
      for the taxable year, no itemized deduction shall be allowed for
      the taxable year. For purposes of this subtitle, the
      determination of whether a deduction is allowable under this
      chapter shall be made without regard to the preceding sentence.
      (2) Time and manner of election
        Any election under this subsection shall be made on the
      taxpayer's return, and the Secretary shall prescribe the manner
      of signifying such election on the return.
      (3) Change of election
        Under regulations prescribed by the Secretary, a change of
      election with respect to itemized deductions for any taxable year
      may be made after the filing of the return for such year. If the
      spouse of the taxpayer filed a separate return for any taxable
      year corresponding to the taxable year of the taxpayer, the
      change shall not be allowed unless, in accordance with such
      regulations - 
          (A) the spouse makes a change of election with respect to
        itemized deductions, for the taxable year covered in such
        separate return, consistent with the change of treatment sought
        by the taxpayer, and
          (B) the taxpayer and his spouse consent in writing to the
        assessment (within such period as may be agreed on with the
        Secretary) of any deficiency, to the extent attributable to
        such change of election, even though at the time of the filing
        of such consent the assessment of such deficiency would
        otherwise be prevented by the operation of any law or rule of
        law.

      This paragraph shall not apply if the tax liability of the
      taxpayer's spouse for the taxable year corresponding to the
      taxable year of the taxpayer has been compromised under section
      7122.
    (f) Aged or blind additional amounts
      (1) Additional amounts for the aged
        The taxpayer shall be entitled to an additional amount of $600 -
       
          (A) for himself if he has attained age 65 before the close of
        his taxable year, and
          (B) for the spouse of the taxpayer if the spouse has attained
        age 65 before the close of the taxable year and an additional
        exemption is allowable to the taxpayer for such spouse under
        section 151(b).
      (2) Additional amount for blind
        The taxpayer shall be entitled to an additional amount of $600 -
       
          (A) for himself if he is blind at the close of the taxable
        year, and
          (B) for the spouse of the taxpayer if the spouse is blind as
        of the close of the taxable year and an additional exemption is
        allowable to the taxpayer for such spouse under section 151(b).

      For purposes of subparagraph (B), if the spouse dies during the
      taxable year the determination of whether such spouse is blind
      shall be made as of the time of such death.
      (3) Higher amount for certain unmarried individuals
        In the case of an individual who is not married and is not a
      surviving spouse, paragraphs (1) and (2) shall be applied by
      substituting "$750" for "$600".
      (4) Blindness defined
        For purposes of this subsection, an individual is blind only if
      his central visual acuity does not exceed 20/200 in the better
      eye with correcting lenses, or if his visual acuity is greater
      than 20/200 but is accompanied by a limitation in the fields of
      vision such that the widest diameter of the visual field subtends
      an angle no greater than 20 degrees.
    (g) Marital status
      For purposes of this section, marital status shall be determined
    under section 7703.