26 USC 74 - Prizes and awards

(a) General rule 
Except as otherwise provided in this section or in section 117 (relating to qualified scholarships), gross income includes amounts received as prizes and awards.
(b) Exception for certain prizes and awards transferred to charities 
Gross income does not include amounts received as prizes and awards made primarily in recognition of religious, charitable, scientific, educational, artistic, literary, or civic achievement, but only if
(1) the recipient was selected without any action on his part to enter the contest or proceeding;
(2) the recipient is not required to render substantial future services as a condition to receiving the prize or award; and
(3) the prize or award is transferred by the payor to a governmental unit or organization described in paragraph (1) or (2) of section 170 (c) pursuant to a designation made by the recipient.
(c) Exception for certain employee achievement awards 

(1) In general 
Gross income shall not include the value of an employee achievement award (as defined in section 274 (j)) received by the taxpayer if the cost to the employer of the employee achievement award does not exceed the amount allowable as a deduction to the employer for the cost of the employee achievement award.
(2) Excess deduction award 
If the cost to the employer of the employee achievement award received by the taxpayer exceeds the amount allowable as a deduction to the employer, then gross income includes the greater of
(A) an amount equal to the portion of the cost to the employer of the award that is not allowable as a deduction to the employer (but not in excess of the value of the award), or
(B) the amount by which the value of the award exceeds the amount allowable as a deduction to the employer.

The remaining portion of the value of such award shall not be included in the gross income of the recipient.

(3) Treatment of tax-exempt employers 
In the case of an employer exempt from taxation under this subtitle, any reference in this subsection to the amount allowable as a deduction to the employer shall be treated as a reference to the amount which would be allowable as a deduction to the employer if the employer were not exempt from taxation under this subtitle.
(4) Cross reference 
For provisions excluding certain de minimis fringes from gross income, see section 132 (e).