The share ratio
Of every dollar members contributed, how many cents reached their medical bills? It is a simple number and the simplicity is the point — it is the one measure a member, a board, a journalist, and a regulator would all reach for first.
Auxilium computes it monthly and on a trailing three-month window, and benchmarks it against the ACA medical loss ratio: 80.0% for individual and small group, 85.0% for large group. Health care sharing ministries are statutorily exempt from that standard. Measuring against it anyway is the entire point — a ministry that clears a bar it is not held to has said something no marketing page can.
If you choose to, you can publish it. One opt-in endpoint exposes the trailing twelve-month ratio and the benchmark comparison, with no member data in it at all.