A recent analysis used Medicare fee-for-service data to compare

... the rate of growth in Emergency Department (ED) payments per beneficiary for patient-centered medical homes (PCMHs) versus non–PCMH practices. According to the study, the rate of growth in ED payments per beneficiary for PCMHs was $54 less for 2009 and $48 less for 2010, relative to non–PCMH practices.

Source: "Emergency department and inpatient hospital use by medicare beneficiaries in patient-centered medical homes," Annals of Emergency Medicine, abstract only, March 11, 2015 http://www.annemergmed.com/article/S0196-0644(15)00003-7/abstract