SCP - State County Plan File, 1993 - 2005


The SCP, the state county plan market penetration file, has been published quarterly through December 2005 and presents aggregate totals of Medicare Advantage enrollees and original Medicare eligibles by state, county and Medicare Advantage organization. At the bottom of this page you will find information on links to CMS data pages with useful files containing Rx enrollment by state, county and Organization.

For the years 2002 - 2005, the SCP, the state county plan market penetration file, was published as a CSV file, SCP-MMYY.CSV, a comma separated file without headers. Prior to 2001 the SCP was published as a fixed width text file. The fields and the field order are the same for all files. The zipped download files below contain a text file, SCPFieldPositions.Txt, which present the field positions for the fixed width files. Note that the archives only contain the December files for each year prior to and including 1997. However the archives since 1998 contain reports by quarter.

Information on Rx enrollment for 2006, aggregated by state, county and plan is presented at the bottom of this page. 

Field Order of the SCP

The SCP contains the following fields in the order indicated. The definitions of these fields are presented beneath..

  • county
  • state
  • H###
  • organization name
  • organization type
  • Social Security state county code
  • eligibles (Original medicare eligibles)
  • enrollee
  • penetration
  • Sum of the A & B Age rates

Definitions of the fields

  • County: The eligibles and enrollees are aggregated by county and state
  • State: The eligibles and enrollees are aggregated by county and state.
  • H###: Every Medicare Advantage Organization (MAO) has potentitally three levels of organization associated with it: (a) The person in the street is familiar with the plan packages such as the standard plan, the silver plan, an employer plan etc. (b) These plans are offered under a contract between the MAO and the CMS. The MAO agrees to provide services for enrollees in its service area in exchange for which the CMS makes payments to the MAO. Each contract has a contract number which typically begins with H and is followed by a 4 digit number. Under the new MAA program contract numbers can begin with other letters. The contract number is usually not seen or known by the public. (c) Any given Organization may offer 1 or several contracts. For example a national organization may offer 2 contracts in two given states. In such a case the organization, the contract number and the plan all have distinct meaning. The SCP file gives the H### or contract number as well as the Organization name. No information or breakdown is given by plan packages.
  • Organization name: See the explanation to the H## field above. The contract # (H###) and organization name are given in the SCP file. Note: Medicare Advantage Organizations typically have two names --- the legal name and the marketing name.
  • Organization type: Every plan is classified as being of a certain type. For example risk plans get paid prospectively at the beginning of the month based on projections of what they expect to spend--hence they are at risk. Cost plans however get paid prospectively at the end of the month. For an explanation and list of the plan types and further documentation see the types section on this page.
  • Social security state county code: This is a five character code uniquely identifying the state and county. Note that in general the social security state county code is distinct from the fips state county code which is more generally used.
  • Eligibles: The number of original Medicare eligibles---individuals who are either currently or formely, entitled or enrolled in either part A or part B original Medicare. We call these the ever enrolled eligibles. The count of the ever enrolled eligibles is typically 2.5%-3% higher than the currently enrolled eligibles. The ever enrolled eligibles also include those individuals who are enrolled in original Medicare with a future effective date. By law, individuals within 4-5 months of their 65th birthday may enroll in original Medicare with an effective date on their birthday. Typically this amounts to 1.5% of the eligible population.
  • Enrollees: The number of Medicare Advantage enrollees---individuals who are currently enrolled in a Medicare advantage plan of some type. The types are listed below and include Risk, Cost, Hcpp, Demo (Demonstrations), Private Fee For Service, PPO, PSO, Pace and PPO Demo. Note that Pace plans did not come under the Medicare Advantage program till December 2003.
  • Penetration: Penetration is a derived field. It equals the ratio of enrollees over eligibles multiplied by 100. For example if a fictitious county had 1000 enrollees and 10,000 eligibles then its penetration would 1000/10000 *100= 10 (The 10 corresponds to 10%.
  • Part AB rate: This is a derived field equal to the sum of the part A and part B rates. The demographic rates are computed annually by the Office of the Actuary for the typical Aged individuals enrolled in either Part A or Part B original Medicare. Under the demographic payment system these rates would be multiplied by age-gender-status factors to obtain the Part A and Part B payment rates for each individual.


The current plan types include

  • RISK plans (Also known as Coordinate Care Plans, CCP, and Health Maintenance Organizations (HMO);
  • COST plans
  • HCPP plans
  • PACE plans (Program for the All Inclusive Care of the Elderly)
  • PFFS plans (Private Fee for Service Plans)
  • PPO (Preferred Provider Organizations---these are paid like Risk plans
  • PSO (Provider Sponsored Organization--there are also paid like Risk plans)
  • DEMO (Demonstration projects)
  • DEMP (PPO Demos, that is demonstration projects using the PPO model)
  • DEMC (Cost Demos, that is demonstration projects using a cost payment scheme)

An explanation of the characteristics of the various plan types may be found in chapter 1 of the Managed Care Manual. The Managed Care Manual may be found in the Regulations and Guidance bucket of the main CMS web page. Under this bucket one should click manuals and then click internet only manuals. The Medicare Advantage manual is publication 100-16.

Important comments on the data

In reviewing the aggregate totals in the SCP file the following five important considerations affecting the interpretation of the data should be considered:

  • Under 11 records
  • Out of (service) Area (OOA) enrollment
  • Non US Counties
  • Month of Record
  • Periods in Blank Records

We now explain each of these topics in detail.

Under 11  records: The privacy laws of the HIPPA act have been interpreted to prohibit publishing aggregate data of 10 or less. Consequently some enrollment fields in the SCP are blank because of enrollment between 1 and 10.

To remedy the loss of data from the under-11 records, each state has a fictitious county field, under-11 which aggregates all deleted enrollees. Data users may redistribute the average number of enrollees deleted among the blank cells. For example, if some state had an enrollment count of 50 for the under-11 county and had 25 blank cells then a user could assume that each blank cell had 2 enrollees. This average while not 100% accurate is useful and can help with trend analysis.

The SC, state county market penetration file, is the only data file listing all counties for which the office of the actuary at CMS computes rates. Consequently, if a Medicare Advantage organization has no enrollment in a particular county then that plan-county-state combination will not be listed in the SCP file. Conversely, every record in the SCP file corresponds to an enrollment of at least one for that Medicare Advantage organization in that county; if the aggregate enrollment is between 1 and 10 inclusive then the enrollment field will be replaced by a blank for the privacy law reason presented above.

Non-US Counties: There is also a fictitious county Unusual SCounty in the fictitious state, 99. This county aggregates all eligibles with a state county code outside the US but not in the protectorates (for example people in Asia). It also aggregates all people with state code 99. This record is put in for purposes of completeness and auditing. Most users will probably wish to delete this record.

However, eligibles with a state county code in the US but not in the list of State County codes used by the Office of the Actuary and not in the list of the State County codes recognized by the United States Postal service, these records, have been omitted with the assumption that they are miscoded. Typically there are 10-15000 (out of 40-45 million) eligibles with US residence in a county that are not recognizable. The number of eligibles in the Unusual SCounty field is typically 3-400,000.

The SCP file has listed Guam since Dec 2003. Since Mar 2004 it has listed Guam (GU), American Samoa (AS), and the Northern Mariana Islands (NI). Prior to these dates the counts for these protectorates were included in the Unusual SCounty record.

OOA (Out of Area): The SCP file lists enrollees and eligibles by their legal state and county of residence; this is the county used for payment purposes. This affects 1/2 - 1 1/2 % of the enrollees. For example a person who moved from Baltimore to Los Angeles and enrolled in say the XYZ Insurance company of California would be paid at the Baltimore rate until the change of address was recorded in the Social Security system.

Consequently, XYZ enrollment records will include both the California counties in the authorized service area of XYZ as well as the counties throughout the rest of the United States where XYZ has enrolless.

Enrollment in each of these out of service area records is however, very often, under 10, leading to surpression of the numbers. Furthermore, the SCP file does not in any way indicate which counties belong to the authorized service area of a Medicare Advantage organization and which counties are outside its service area. To study the enrollment of each Medicare Advantage plan in its authorized service area one should use the Geo, Geographic Service area report located on the Geo page of this websection. Note however that the SCP report goes back to 1993 while the Geo report only goes back to 2001.

Month of record: Users of the data should be aware that for example the Dec 1998 SCP file may present Medicare Advantage enrollee counts for Jan 1999 but original medicare eligibles for Dec 1998. The name of the file may reflect this one-month mismatch. For example, the Dec 1998 SCP file has filename scp-0199.txt, instead of scp-1298.txt This one-month mis-match between MA enrollees and original Medicare eligibles, happened in some of the older files, especially between 1998 and 2001.

A major reason for the mismatch is because during one period of time the legislation in effect could delay the effective date of enrollment for up to 45 days. For example, a person enrolling in a plan on Dec. 20th, would have an effective date of Feb 1st of the following year. To offset this mismatch between effective date and physical enrollment date the creators of the file during this time period used Medicare Advantage enrollment figures one month delayed from the month of the original Medicare eligibles. Therefore the December file would use original Medicare eligibles from December but Medicare Advantage enrollees from January.

Since 2002 the month of enrollment and eligibles have been the same as the month of the report. However users of older reports should bear in mind that the as of date of enrollment may be one month later.

Because of all the above, researchers using the SCP data should footnote their reports, as appropriate, and indicate that a) under-11 records have been deleted, b) MA enrollment includes out of service area enrollees and c) the as of month for enrollees may be up to one month more than the filename month.

Periods in Blank Records: The csv and text files were created with SAS. SAS inserts a period in a blank numeric field. This period may intefer with the capacity of some programs, such as excel, to subtotal columns. A simple remedy to this problem is to replace cells with only a period with a blank (Care must be taken not to remove the periods from the penetration and from the AB rates amount which also contain periods.)

2006 Data

Since we have a new legislative program the 2006 data files will never be in the same format as the old pre-2006 files. For example, the word plan now has two distinct meanings: It can refer to Prescrption Drug Plans (PDP) or to Medicare Advantage Plans with a Prescription Drug component (MA-PD).  There is CMS data on the web which gives Rx enrollment (but not MA-only Enrollment) by A) State, B) State County, C) State County Org and by D) Organization.  On the Related Links Inside CMS section on these data pages, located below, I have added links to these data pages. Upon clicking the links you will see files which resemble but are not identical to the pre-2006 files. The files will contain Rx (but not MA-only) enrollment by either a) State, b) State County, c) State County Organization, or d) Organization.

I have used the same notation to indicate file names; however this is notational only: For example SC-0406 is a file which contains enrollment by State and County and thus resembles the pre-2006 sc-mmyy files. However SC-0406 differs in significant respects from the pre-2006 files in that a) it reports Rx enrollment but not MA-only enrollment, b) FIPS codes are used vs. social security state county codes, c) Organization names are used vs. H####.

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