By law, every scheme must hold at least 25% of annual contributions in reserves. If a scheme collects R10 billion in a year, it must have at least R2.5 billion in the bank to pay future claims. This is what makes medical schemes financially safer than for-profit insurers: they can't be drained by shareholders and they have a regulated buffer for bad years.
SA example: Discovery Health Medical Scheme deferred its 2026 contribution increase from January to April because its 31.6% solvency level gave it the buffer to absorb three months of unfunded increases.