The national survey by the Washington-based Center for Studying Health System Change shows the proportion of physicians providing such charity care has fallen to 68 percent from 76 percent during 1996-97.
That decline occurred even as the number of uninsured Americans grew to 45.5 million during 2004, signaling growing stress on the healthcare safety net.
"The decline in physician charity care -- long a critical part of the safety net -- is alarming given the increase in the number of uninsured Americans," said Paul Ginsburg, president of HSC, a non-partisan policy research organization.
The percentage of physicians providing any free or reduced-cost care decreased to 68.2 percent during 2004-05 from 71.5 percent in 2000-01, continuing a trend that dates to at least 1996-97, when 76.3 percent of physicians provided charity care.
However, despite a proportional decrease in physicians providing charity care, the center reports the number of physicians offering charity care has remained relatively stable because the overall number of U.S. practicing physicians has increased.