The figure was up by 4,000 on the same period in 2024 and 16% higher than the 432,000 recorded in Q1 to Q3 2019, before the pandemic.
Broadstone said NHS waiting lists were broadly unchanged over the same period, standing at 7.40 million in Q3 2025.
Separate NHS England data also showed 1.81 million patients were waiting for diagnostic tests at the end of January 2026, with 25% waiting six weeks or more. Waiting times for diagnostic tests such as X rays and MRIs rose by 12% over the year, according to the analysis.
Total private health admissions, including self pay, reached 710,000 across the first three quarters of 2025 - which Broadstone said suggests the market could approach one million treatments a year if current demand continues.
Brett Hill, head of health & protection at Broadstone, said: "The growth of PMI-funded treatment shows how integral the private health market is becoming to the nation’s health.
"While we have seen waiting lists decrease slightly over the last couple of years, significant pressures persist, including the ongoing threat of industrial action, and businesses understand that they can no longer rely on the NHS to ensure the good health of their employees.
"As a result, PMI-funded admissions – the majority of which are funded by employer-paid schemes – have risen significantly above pre-pandemic levels. Industry data reinforces this trend with the latest ABI data showing that a record £4 billion was paid out in health claims in 2024, highlighting the scale and cost of this demand.
"It looks likely that we will soon be seeing over 1 million private treatments every year as businesses expand their health insurance coverage and this inevitably feeds through into an increasing volume of claims."
