Amends the Internal Revenue Code to provide that with respect to a qualified joint business conducted by a husband and wife who file a joint return: (1) such joint business shall not be treated as a partnership; (2) all items of income, gain, loss, deduction, and credit shall be divided between the spouses as they designate; and (3) each spouse shall take into account such spouse's respective share of such items as if attributable to a sole proprietorship.Includes each spouse's share of income or loss from a qualified joint business in determining net income from self-employment.