http://www.academyhealth.org/blog/2017-01/private-vs-public-prices

You probably knew that the prices private health insurers pay hospitals are higher than those of Medicare and Medicaid. But you may not have known that the gap between private and public payers used to be a lot smaller and has grown tremendously in recent years.

Using Medical Expenditure Panel Survey (MEPS) data, by payer (private health insurance, Medicare, and Medicaid) and over time (1996-2012), the chart shows average hospital payment rates (in constant dollars), adjusted for age, sex, race/ethnicity, geography, income, health conditions, charges, length-of-stay, and whether or not a surgical procedure was performed. To produce figures for the chart, the authors used this model to predict hospital payment per stay for each MEPS observation, as if they were covered by private insurance, Medicare, or Medicaid, in turn.

As is clear from the chart, adjusted, average private pay rates have always been above public rates, but were closest in 1996-2000. Back then, private rates were no more than 10% above Medicare rates. Perhaps this was the effect of managed care, which kept growth in private rates down. Those rates began to grow during the managed care backlash, until 2005. From 2005-2009, adjusted, average private hospital rates—while considerably above Medicare and Medicaid rates—held steady. Then, in 2009, they took off again. In 2012, adjusted, average private rates were about 75% higher than Medicare rates.*

Medicaid payments were about 90% of Medicare’s in most study years.