26 U.S.C. § 212: Expenses for production of income

In the case of an individual, there shall be allowed as a deduction all the ordinary and necessary expenses paid or incurred during the taxable year—(1) for the production or collection of income; (2) for the management, conservation, or maintenance of property held for the production of income; or (3) in connection with the determination, collection, or refund of any tax.