1. Center for Medicare and Medicaid Innovation. Request for Information: Evolution of ACO Initiatives at CMS. 2014. (Accessed March 14, 2014, at http://innovation.cms.gov/Files/x/Pioneer-RFI.pdf .)
2. Centers for Medicare and Medicaid Services. Pioneer Accountable Care Organizations succeed in improving care, lowering costs., 2013. (Accessed March 14, 2014, at http://www.cms.gov/Newsroom/MediaReleaseDatabase/Press-Releases/2013-Press-Releases-Items/2013-07-16.html .)
3. Medicare Payment Advisory Commission. Report to the Congress: Medicare Payment Policy. 1999; p72. (Accessed March 14, 2014, at http://www.medpac.gov/documents/Mar99%20Entire%20report.pdf .)
4. Centers for Medicare and Medicaid Services. Medicare Hospital Value-based Purchasing Program. (Accessed March 14, 2014, at http://www.cms.gov/Medicare/Quality-Initiatives-Patient-Assessment-Instruments/hospital-value-based-purchasing/index.html?redirect=/hospital-value-based-purchasing .)