Volunteer Income Tax Assistance (VITA) Act This bill directs the Internal Revenue Service (IRS) to establish a Community Volunteer Income Tax Assistance Matching Grant Program (VITA grant program) for the development, expansion, or continuation of volunteer tax preparation programs to assist low-income taxpayers and members of underserved populations. The program must be administered in the same manner as the Community Volunteer Income Tax Assistance matching grants demonstration program established under the Consolidated Appropriations Act, 2008. The bill establishes the National Center to Promote Quality, Excellence, and Evaluation in Volunteer Income Tax Assistance to: promote the adoption of a universally accessible volunteer training platform for the preparation of federal income tax returns, provide technical assistance to tax return preparation program managers, identify and disseminate best practices related to tax site management, support outreach and marketing efforts, and evaluate programs and activities funded under this bill. The IRS must: (1) designate, through a competitive process, a lead national organization to carry out the purposes of the center; and (2) provide an annual grant to the organization. The lead national organization may provide subgrants to organizations to facilitate specialized technical assistance in reaching one or more underserved populations. The bill amends the Domestic Volunteer Service Act of 1973 and the National and Community Service Act of 1990 to authorize several national service programs to provide tax preparation assistance for low-income and older individuals and families.