Commonsense Reporting Act of 2019 This bill addresses the eligibility verification process for the premium assistance tax credit and cost-sharing subsidy under the Patient Protection and Affordable Care Act (PPACA). It requires the Department of the Treasury to develop and implement a reporting system that allows employers to voluntarily report information about their health plans for the current plan year prior to the beginning of open enrollment. The bill also allows electronic transmission of employee and enrollee statements and permits Treasury to accept full names and dates of birth in lieu of dependents' and spouses' Social Security numbers. The Government Accountability Office must evaluate (1) for the period beginning on January 1, 2015, and ending on December 31, 2018, the notification of employers by PPACA exchanges of the eligibility of employees for advance payments of the premium assistance tax credit or cost-sharing subsidies; and (2) for calendar year 2020, the functionality of the prospective reporting system established by this bill, including the accuracy of information collected.