The recession has fueled the greatest influx of Americans onto Medicaid since the earliest days of the public insurance program for the poor, according to new findings that show caseloads have surged in every state.

More than 3 million people joined Medicaid in the year that ended in June, the data released Thursday show. That pushed enrollment to a record 46.8 million, exacerbating the financial strains on already burdened states and complicating the federal politics of health care.

The analysis by the Kaiser Family Foundation, a health policy and research organization, found that in three-fifths of the jurisdictions, including Maryland and the District, people rushed into the safety net for health coverage at more than twice the rate as the year before.

Medicaid directors said in interviews that despite early clues elsewhere that the economy may be starting to improve, the demand for government health coverage has not tapered off since last summer. "Nope. It hasn't slowed down yet," said John Folkemer, deputy secretary for health-care financing for Maryland, where the caseload rose by 20 percent from June 2008 to June 2009, the steepest increase in the country.

Like the rising demand for food stamps and welfare benefits, the increase in people turning to Medicaid reflects the millions of Americans who have lost jobs and economic self-reliance and are asking the government for basic help, in many instances for the first time.

Because the program is large and expensive, the spurt in Medicaid caseloads has produced far more damaging effects on state budgets than the other two programs. In the past year or two, many states have responded by reducing the medical services available to Medicaid patients or payments to doctors, hospitals and other providers of health care.