At the same time, the percentage of Americans who said they were uninsured rose from 16.4 percent in 2010 to 17.1 percent in 2011, the fourth straight year of increases, the poll found.
Gallup said the increase in uninsured Americans, from 14.8 percent in 2008, appears to be the result of higher unemployment and underemployment in 2011 than in 2008 and fewer employees getting health insurance from employers because the employers didn't offer it or employees couldn't afford it.
The percentage of Americans who said they got their health insurance from an employer declined from 45.8 percent in 2010 to 44.6 percent in 2011, the poll found.
Among employed Americans not working for the government, 57.1 percent said they got health insurance from their employer and the proportion has declined steadily since 2008.
Increasingly, Americans were uninsured or relying on insurance from a government program, Gallup said.
Gallup noted rising healthcare costs, citing a Kaiser Family Foundation survey that found the average annual premium for employer-sponsored family health insurance coverage cost $15,073 last year, up 9 percent from 2010. The survey found workers contributed an average of $4,129 and employers $10,944.
The poll is based on telephone interviews Jan. 1-Dec. 31, 2011, with a random sample of 353,492 adults, and has margin of error of 1 percentage point.