The main purpose of the Service Members Tax Relief Act is to provide tax relief for active and reserve members of the Uniformed Services of the United States by exempting certain types of income from federal income tax. This legislation aims to recognize and support the financial well-being of military personnel by alleviating some of their tax burdens. Key provisions of the Act include a specific exemption from gross income for compensation received by active or reserve service members for their military service during the taxable year.