February 9, 2017
Encounter data is detailed data generated by health care providers, such as doctors and hospitals, that documents both the clinical conditions they diagnose as well as the services and items delivered to beneficiaries to treat these conditions. The Centers for Medicare & Medicaid Services (CMS) began collecting encounter data from Medicare Advantage plans in 2012.
In 2016, CMS began to base 10 percent of the Medicare Advantage enrollee risk score calculation on diagnoses submitted through encounter data.
For 2018, CMS is proposing to maintain the proportion of the risk score based on encounter data at 25 percent.
Two recent studies from Milliman and Avalere found that risk scores calculated based on encounter data were 4 percent to 16 percent lower on average in comparison to the current data system.