Health Maintenance Organizations (HMOs): 1990 to 2006

Added By Infochimps

The Statistical Abstract files are distributed by the US Census Department as Microsoft Excel files. These files have data mixed with notes and references, multiple tables per sheet, and, worst of all, the table headers are not easily matched to their rows and columns.

A few files had extraneous characters in the title. These were corrected to be consistent. A few files have a sheet of crufty gibberish in the first slot. The sheet order was shuffled but no data were changed.

The tables that were changed (this is table 144):

0166 0257 0362 0429 0445 0446 0459 0461 0462 0464 0465 0466 0467
0469 0479 0480 0481 0482 0483 0484 0485 0486 0487 0559 0628 0629
1144 1227 1231

This dataset consists of a table of 22 rows and 21 columns.

As of January 1, except as noted (9.1 represents 9,100,000). An Health Maintenance Organization is a prepaid health plan delivering comprehensive care to members through designated providers, having a fixed periodic payment for health care services, and requiring members to be in a plan for a specified period of time (usually 1 year). A group Health Maintenance Organization delivers health services through a physician group that is controlled by the Health Maintenance Organization unit or contracts with one or more independent group practices to provide health services. An individual practice association (IPA) Health Maintenance Organization contracts directly with physicians in independent practice, and/or contracts with one or more associations of physicians in independent practice, and/or contracts with one or more multispecialty group practices. Data are based on a census of HMO’s.


  1. 1990-1995 exclude enrollees participating in open-ended plans; beginning 1999, includes open-ended enrollment.
  2. Starting with 2004 data, Puerto Rico and Guam included in the total.
  3. 2006 data includes “HMO Medicaid only plans” for the first time.
  4. 2005 and 2006 totals include plans that did not provide enough information to be classified as a model type.
  5. 2006 data includes data for “Network, Staff and Group” types categorize under the “Group” model type.


Public Domain (Government Work)

This dataset was prepared by the government and is therefore in the public domain. There are no restrictions upon its use.