Health Plans, Reports, Files and Data

Health Plans, Reports, Files and Data


This page contains several files presenting aggregate Medicare Advantage (MA) enrollment, and Original Medicare eligible counts. Throughout this web section the term enrollee will refer to an enrollee in a Medicare Advantage plan (offered by an MA Organization) of some type: Risk, Cost, Pace, PFFS etc; similarly eligible will refer to an individual entitled or eligible for some aspect of Original Medicare (independent of whether that individual also belongs to an MA plan).

The data in this section is historic pre-2006 data. For pre-2006 data the term eligible refers to any person currently or ever enrolled or entitled to either part A or part B Medicare or both. Typically the ever eligible count is about 2.5%-3% higher than the currently eligible count.

The term enrollee refers to an enrollee in a Medicare Advantage or Managed Care plan. Since payment for risk plans is prospective, enrollment is as of the 1st of the month. For example, the enrollment for an organization for say Mar 2003 reflects all individuals enrolled in that plan with an enrollment effective date on or before Mar 1 2003. CMS pays organizations prospectively on the 1st of the month for the estimated cost by the plan for its enrollees during that month (Hence the term risk plan). The enrollment for the 1st of the month is typically available the 3rd week of the preceding month. Data users should bear in mind that regulations allow, under limited circumstances, retroactive enrollment for up to 36 months. Typically the monthly enrollment you see will change by only 1-2% over future months. The enrollment fields reflect the fact that Pace plans were not all officially Managed care plans until December 2003. It was the policy of CMS, prior to 2006, not to publish plan data---all enrollment figures reflects aggregate enrollment at the organization level.

As more data becomes available we will publish it and also update this overview section.

High Level Overview of the Different Reports

In the left hand pane are links to several pages each which, except for the institutional report, contains reports on enrollment and eligible counts. The reports are periodic and historical, that is, they are published at regular intervals and are archived on the page. The reports differ in the period of publication (quarterly, monthly) and how far back the archives go. The reports differ in how they are aggregated. A brief description is presented in the table below. This information is duplicated with further details on each link.

The aggregated column in the table below describes what fields the enrollment and eligibles are aggregated by. The best used for column is a rough description of what the report is best used for. Each report may have other uses depending on specific user projects and interest. The comments field contains information about the data.

Data users should bear in mind that the privacy requirements mandated in HIPAA have been interpreted to prohibit publishing aggregate data of 10 or less. Therefore some cells in the enrollment column may be blank. For all reports (except the state county market penetration report) a blank cell indicates that there is enrollment between 1 and 10. On many reports these missing enrollees are aggregated by state. This allows average re-distribution of the below 11 data into the blank cells. For many purposes this re-distribution is useful and sufficient. The state county market penetration report is the only enrollment report containing all counties for which the office of the actuary at CMS has determined a payment. Consequently, blank cells in the state county report may indicate either zero enrollment (if there is no access in that county) or an enrollment between 1 and 10. Data users should bear in mind that the percent of data lost to the below 11 records varies from file to file. Hence certain files are better for certain purposes.

The institutional report contains a list of all providers that are certified as institutions. This means that residents of the certified part of these institutions have institutional status for demographic payment purposes. The institutional status still has relevance for payment in 2006 and 2007. This report contains no enrollment.

Short FileNameLong NamePeriodAggregated byBest used forComments
SCState County
Market Penetration
QuarterlyState CountyState county
enrollment &
GSA, GeoGeographic
Area report
MonthlyState County PlanState county
plan enrollment
Enrollment is
Service Area
MonthlyMonthlyMonthlyPlanPlan enrollment
& plan attributes
such as for profit etc
Plan enrollment
also exists on geo
and 13 month report
MonthlyPlan TypeHigh level overview of
plan enrollment
This report is derived from
the monthly report
13-Month13-MonthMonthlyPlanTrends in plan
The report
contains 13
months of
Trend stTrend stateQuarterlyState CountyPenetration
trends by state
This report is derived from
the sc report
ByRoTypeByRoTypeMonthlyRegional Office & Plant typeEnrollment and number of plans by either Plan Type or
Geographic area
Number & percentage of
plans by either
plan type or
geographic region
InstInstitutionalQuarterlyNot ApplicableList of providers certified as institutions
for purposes of the
institutional status of demographic payment
Institutional status is still relevant for 2006 and 2007

Page Last Modified:
09/06/2023 04:57 PM