Save Social Security Act of 2017 This bill amends the Internal Revenue Code and title II (Old Age, Survivors and Disability Insurance) of the Social Security Act to: (1) apply Social Security payroll taxes to annual income above $300,000; (2) include earnings above $300,000 in the benefit formula; and (3) increase to $100,000 the income threshold above which Social Security benefits are included in gross income. (Under current law, Social Security payroll taxes apply to the first $127,200 of income in 2017 and benefits are included in the gross income of individuals with certain income that exceeds thresholds of $0, $25,000, or $32,000, depending on the individual's filing status.)