One of three American children lives in a household that receives some form of government welfare, including food stamps, Medicaid or cash payments, the Census Bureau said yesterday.

These benefits, based on a means test, are far more common among black and Hispanic children -- under 18 -- than among white children. One of four white children in 1984 lived in households receiving one or more means-tested benefits, compared to 68 percent of black children and 52 percent of Hispanic children.

In a second report, the Census Bureau said yesterday that 76.7 million of the nation's 86.8 million households in 1984 received one or more of eight major noncash benefits from the government or private employers. The total value of all these benefits, based on figures compiled by the Census Bureau and the Employee Benefit Research Institute, exceeded $300 billion.

In some cases, the noncash benefit was based on need -- for example, food stamps and Medicaid. But in four-fifths of the cases involving $250 billion of the $300 billion, no income test was required, such as on-the-job health insurance, which therefore went primarily to the nonpoor.

The Census survey of children found that only half of the black and Hispanic children are covered by private health insurance, while three-quarters of the white children are covered.

The survey indicates that female-headed families with children, and families with high unemployment, are by far the most common recipients of means-tested benefits.

For example, 68 percent of all children in female-headed households at the time of the survey were getting such benefits; among blacks and Hispanics, the figure was 85 percent. And 73 percent of children living in homes with no working adult were in female-headed households.

According to the survey, 46 percent of black children live in female headed households.

The means-tested government program that most children received was free and reduced-price school meals. Over a fifth, or about 23 percent, of nonfarm children received government help with their school meals.

The rates at which children participated in other government benefit programs varied: 14.4 percent received food stamps; 12.6 percent received Medicaid; 5.2 percent were living in subsidized housing; 13.6 percent get cash public assistance, and 5.2 percent get food benefits under the food supplement program for women, infants and children (WIC).

In its report on noncash benefits, the bureau said that 14.6 million of the 86.8 million U.S. households got one or more government benefits based on need. These benefits were valued in an earlier report at about $51.5 billion. About half those receiving benefits were below the government's official poverty line, the rest somewhat over.

The means-tested programs were food stamps (7 million households), free or reduced price school meals (5.6 million), subsidized housing (3.6 million), and Medicaid (8.3 million households). These numbers add up to more than 14.6 million because some families got more than one type of benefit.

About 70.7 million households in all income ranges got about $250 billion in noncash benefits not based on need. This included 49.6 million households with on-the-job health insurance (value $97.2 billion, according to EBRI), and 38 million households where a worker was earning credits toward a pension other than Social Security. EBRI estimated employer pension contributions at about $92 billion.

Medicare covered 21.4 million households, with benefits estimated at $60.9 billion, and nonsubsidized school lunches went to 11.1 million households ($629 million).