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From its inception, Medicare has included two separate but
coordinated programs: Hospital Insurance (Part A) and
Supplementary Medical Insurance (Part B). Part C (Medicare
Advantage, previously known as Medicare+Choice) was
established by the Balanced Budget Act of 1997 as an
expanded set of options for the delivery of health care under
Medicare. Although all Medicare beneficiaries can receive
their benefits through the original fee-for-service program,
most beneficiaries enrolled in both Part A and Part B have
the option to participate in a Medicare Advantage plan
instead.
Organizations that seek to contract as Medicare Advantage
plans must meet specific organizational, financial, and other
requirements. Although most Medicare Advantage enrollees
are in coordinated care plans, such as health maintenance
organizations and preferred provider organizations,
Medicare Advantage plans also include private fee-forservice
plans, provider-sponsored organizations, special
needs plans, and medical savings account plans (MSA plans,
which provide benefits after a single high deductible is met).
Medicare Advantage plans are generally paid on a capitation
basis—that is, plans are paid a predetermined amount per
member per month, which is adjusted according to the
health status of the plans' members—and are required to
provide at least those services covered by Parts A and B,
except hospice services. Plans may (and in certain situations
must) provide extra benefits (such as vision or hearing
coverage) or reduce cost sharing or premiums.
The Medicare Prescription Drug, Improvement, and
Modernization Act (also called the Medicare Modernization
Act, or MMA) was passed on December 8, 2003. The MMA (P.
L. 108–173) established a voluntary prescription drug
benefit for Medicare beneficiaries and created a new
Medicare Part D. People eligible for Medicare could begin to
enroll in Part D beginning in January 2006. For more
information, see: http://www.medicare.gov/publications/
pubs/pdf/10050.pdf and http://www.cms.gov/Research­
Statistics-Data-and-Systems/Statistics-Trends-and-Reports/
MedicareMedicaidStatSupp/2013.html. (Also see Appendix
II, Fee-for-service health insurance; Health insurance
coverage; Health maintenance organization [HMO];
Managed care; and Appendix I, Medicare Administrative
Data.)
Metropolitan statistical area (MSA)—The Office of
Management and Budget (OMB) defines MSAs according to
published standards that are applied to U.S. Census Bureau
data. The standards are revised periodically, generally prior
to the decennial census, and are applied to the census data
to delineate the statistical areas. Revisions to the areas are
implemented between censuses by using updated
population estimates. The most recent standards were
released in June 2010 (available from: http://
www.whitehouse.gov/sites/default/files/omb/assets/
fedreg_2010/06282010_metro_standards-Complete.pdf).
In February 2013, OMB released a new delineation of
the nation's metropolitan and micropolitan statistical
areas based on the 2010 standards (available from:
http://www.whitehouse.gov/sites/default/files/omb/
bulletins/2013/b13-01.pdf). New MSA delineations are
incorporated into individual data systems at different times.
In the 2000 and 2010 standards, an MSA is a county, or
group of contiguous counties, that contains at least one
urbanized area with a population of 50,000 or more.
In addition to the county or counties that contain all or
part of the urbanized area, an MSA may contain other
counties if there are strong social and economic ties with
the central county or counties, as measured by commuting.
Counties that are not within an MSA are considered to be
nonmetropolitan. For more information, see:
http://www.census.gov/population/metro/ and
http://www.whitehouse.gov/omb/bulletins_fy05_b05-02.
Most data by MSA currently in Health, United States are
based on the June 2003 OMB definitions (2000 OMB
standards applied to 2000 census data). (Also see Appendix
II, Urbanization.)
National Health Interview Survey (NHIS)—For respondents
to NHIS, designation of place of residence as
metropolitan or nonmetropolitan is based on the
following MSA definitions: for 2006 and beyond, on the
June 2003 OMB definitions (2000 OMB standards applied
to 2000 census data); for 1995–2005, on the June 1993
OMB definitions (1990 OMB standards applied to 1990
census data); and for 1985–1994, on the June 1983 OMB
definitions (1980 OMB standards applied to 1980 census
data). For estimates based on 2006 NHIS data combined
with earlier years of NHIS, metropolitan status of
residence for all years involved is based on the June 2003
definitions. Introduction of each set of standards may
create a discontinuity in trends.
National Immunization Survey (NIS)—Designation of
place of residence as metropolitan or nonmetropolitan
for respondents to NIS is based on 2000 census data and
the MSAs delineated in 2003, as well as the following
versions and revisions of MSA definitions: for 2011 and
2012, on the December 2009 definitions; for 2010, on the
November 2008 definitions, for New England, the
county-based areas were used; for 2009, on the
November 2007 definitions, for New England, the
county-based areas were used; for 2008, on the
December 2006 definitions, for New England, the
county-based areas were used; for quarter 4 of 2007, on
the December 2006 definitions; for quarters 1–3 of 2007,
on the December 2005 definitions, for New England, the
county-based areas were used in 2007; for 2006, on the
November 2004 definitions, for New England, the
county-based areas were used; for 2005, on the
December 2003 definitions, for New England, the
county-based areas were used; for quarters 3 and 4 of
2004, on the December 2003 definitions; and for quarters
1 and 2 of 2004 and quarter 4 of 2003, on the June 2003
definitions. For 2003–2004 for New England, the
county-based areas were used. For more information,
see: http://www.census.gov/population/metro/.
430 Appendix II. Definitions and Methods Health, United States, 2014