Primary Care Spending Transparency Act: This bill, the Primary Care Spending Transparency Act, would require a health care service plan or health insurer that reports rate information, as specified, to annually report the percentage of expenses the health care service plan or health insurer allocated to primary care, among other things. The bill would require the Department of Managed Health Care and the Department of Insurance to annually compile and post a report with that information on their Internet Web sites, beginning January 1, 2020, and would require the departments to include their reports as discussion items at specified public meetings. The bill would also require a managed health care plan to annually report specified information to the State Department of Health Care Services, which would be required to annually compile and post a report with that information on its Internet Web site, beginning January 1, 2020. The bill would require the Department of Managed Health Care and the Department of Insurance to convene the Primary Care Payment Reform Collaborative no later than January 1, 2020, to propose revisions to the types of primary care data collected from health care service plans and health insurers, as well as to advise and assist in developing specified best practices. The bill would prescribe the membership of the Primary Care Payment Reform Collaborative.