Save Social Security Act of 2019 This bill modifies the requirements for Social Security payroll taxes and benefits to apply Social Security payroll taxes to annual income above $300,000, include earnings above $300,000 in the benefit formula, and increase to $100,000 the income threshold above which a portion of a taxpayer's Social Security benefits is included in gross income. (Under current law, Social Security payroll taxes apply to the first $132,900 of income in 2019 and a portion of benefits is 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.)