The notion that hospital readmission rates are a “quality” measure reached the status of conventional wisdom by the late 2000s. In their 2007 and 2008 reports to Congress, the Medicare Payment Advisory Commission (MedPAC) recommended that Congress authorize a program that would punish hospitals for “excess readmissions” of Medicare fee-for-service (FFS) enrollees. In 2010, Congress accepted MedPAC’s recommendation and, in Section 3025 of the Affordable Care Act (ACA) (p. 328), ordered the Centers for Medicare and Medicaid Services (CMS) to start the Hospital Readmissions Reduction Program (HRRP). Section 3025 instructed CMS to target heart failure (HF) and other diseases MedPAC listed in their 2007 report.  State Medicaid programs and the insurance industry followed suit.
Today, twelve years after MedPAC recommended the HRRP and seven years after CMS implemented it, it is still not clear how hospitals are supposed to reduce the readmissions targeted by the HRRP, which are all unplanned readmissions that follow discharges within 30 days of patients diagnosed with HF and five other conditions. It is not even clear that hospitals have reduced return visits to hospitals within 30 days of discharge. The ten highly respected organizations that participated in CMS’s first “accountable care organization” (ACO) demonstration, the Physician Group Practice (PGP) Demonstration (which ran from 2005 to 2010), were unable to reduce readmissions (see Table 9.3 p. 147 of the final evaluation) The research consistently shows, however, that at some point in the 2000s many hospitals began to cut 30-day readmissions of Medicare FFS patients. But research also suggests that this decline in readmissions was achieved in part by diverting patients to emergency rooms and observation units, and that the rising rate of ER visits and observation stays may be putting sicker patients at risk  Responses like this to incentives imposed by regulators, employers, etc. are often called “unintended consequences” and “gaming.”