This document is about the annual report on private sector employer-sponsored group health plans that filed a Form 5500 in 2015. It provides detailed information and statistics on the number of plans, participants, assets, liabilities, income, and expenses for self-insured, fully-insured, and mixed-insured health plans. The report also examines plan characteristics such as funding arrangements, collective bargaining status, and industry. The data is extracted from the 2015 Form 5500 filings and provides a comprehensive overview of the private sector group health plan landscape.