Nonprofits Support Act This bill modifies the requirements for determining the unrelated business taxable income of tax-exempt organizations. The bill repeals provisions that (1) require organizations with more than one unrelated trade or business to compute unrelated business taxable income separately for each trade or business; and (2) increase unrelated business taxable income by the amount of expenses paid or incurred by an organization for certain fringe benefits for which a tax deduction is not allowed, including benefits relating to transportation, parking, or an on-premises athletic facility.