Protecting Our Children's Future Act of 201 9 This bill makes several changes to the federal budget process. The changes to the budget process include converting the existing annual budget and appropriations process to a biennial process; changing the calendar period for the federal fiscal year (currently October 1 through September 30) to January 1 through December 31; requiring mandatory spending programs to be subject to the appropriations process with exceptions for Social Security, Medicare, programs administered by the Department of Veterans Affairs, and TRICARE; requiring the baseline budget of each department or agency to be assumed to be zero and each proposed expenditure to be justified as if it were a new expenditure; requiring Congress to consider appropriations bills using procedures similar to the existing budget reconciliation process, which includes expedited procedures that prevent a filibuster and restrict amendments in the Senate; and withholding pay for Members of Congress if the House and Senate have not jointly agreed to a congressional budget resolution by June 30 of the first year of a Congress.