This Issue Brief reviews
surveys that provide estimates of the uninsured
population in the United States. It includes a discussion
of why the estimates from the various surveys differ.
It is important to understand the
differences in the estimates of the uninsured population.
The projected cost of implementing policy proposals
depends on the estimates of the number of people affected
by the proposals; for instance, the allocation of funding
for the State Children's Health Insurance Program
(S-CHIP) depends heavily on the available estimates. In
addition, the estimated effectiveness of policy proposals
to reduce the uninsured population will be accurate only
if the correct count is known and the precise make-up of
the uninsured population is understood.
Currently, seven surveys can be
used to make nationally representative estimates of the
number of people without health insurance coverage. Some
of the surveys collect health insurance information in
the context of obtaining general information on health
care, while other surveys are focused on other topics
such as labor force participation and public assistance
The most widely used survey that
collects information on health insurance coverage is the
Current Population Survey (CPS), conducted by the Census
Bureau. The most recent estimates from the CPS suggests
that 44.3 million Americans were uninsured in 1998.
Besides the CPS, a number of other
surveys collect information on the uninsured population.
They include the Survey of Income and Program
Participation (SIPP), Behavioral Risk Factor Surveillance
System (BRFSS), Community Tracking Study (CTS), Medical
Expenditure Panel Survey (MEPS), National Health
Interview Survey (NHIS), and the National Survey of
America's Families (NSAF). Estimates of the uninsured
from these surveys range from 19 million to 44 million
and vary depending on the time frame the survey covers.
A number of states have started to
question the validity of the uninsured estimates from the
CPS, and other surveys, because of the small sample size
in many states. As a result, some states have begun to
conduct their own surveys to determine the number of
uninsured residents. States that regularly conduct their
own surveys include Florida, Massachusetts, Minnesota,
New Mexico, Oregon, Vermont, and Wisconsin.
Unfortunately, the various state surveys are not easily
Research needs to continue to
increase understanding of the differences among the
surveys and to improve on methodologies to count the
uninsured, as the future of public programs, such as
S-CHIP and other state and local initiatives to expand
health insurance coverage, depends on the accuracy of
these estimates. Whatever survey is used, the results
show that a substantial number of Americans do not have
any health insurance coverage, and the number has been