With all of the focus on M4A recently, in its many permutations, we’re hearing a growing concern among hospital executives and physician leaders that their economics could be in serious peril. (For more on this, see the below anecdote from “on the road”.) That concern is justified, as you can see from the graphic below.

On the left, we show data on payment-to-cost ratio for hospitals since the start of the 2000s. As you can see, hospitals rely heavily on a cross-subsidy model—Medicare and Medicaid reimbursement covers only 86 to 88 percent of the total cost of inpatient care delivery. Hospitals make up this difference, and generate a positive margin, by negotiating rates for commercially-insured patients that cover almost 145 percent of costs. As health systems have consolidated and built negotiating leverage, that percentage has steadily risen over the past several years, more than offsetting losses on publicly-insured patients.

The problem? Those lucrative commercial patients only account for a third of admissions, as shown at the bottom right. And across the past decade and a half, commercial admissions have dropped by more than 20 percent. In other words, hospitals have been consolidating and raising commercial rates on a declining book of business in order to compensate for underpayment on a growing volume of government-paid cases.

Now imagine that the commercial business disappeared entirely, and you can see what would happen—hospital finances would crater. Under M4A, Medicare rates would have to go up substantially to make up for the lost margin on commercial cases. Even if M4A turned out to be “Medicare Advantage for More”, trading commercial admissions (say, for the 55-65 population) for MA admissions (which are generally paid at Medicare FFS rates), this would create a difficult situation for hospitals.

In our view, this economic reality is not getting discussed enough in the current debate over M4A.