Almost 5 percent of Americans struggle living just one step above poverty, according to a new report by the Census Bureau.

The ranks of the near-poor, as they are called, are more likely to be women than men, and lack even a high school degree, the report said. The highest rate, 6.3 percent, was among African Americans.

The census report examining what has happened to the near-poor since the mid-1960s shone a spotlight on those whose incomes rise above poverty thresholds, but only by 25 percent or less. In 2012 dollars, a family of four would be considered near-poor if their income fell between $23,283 and $29,104.

For many, that was not enough to get by without some public assistance. Nearly a third of the near-poor received benefits under the Supplemental Nutrition Assistance Program, or what used to be known as food stamps, while 85 percent had someone in the house receiving a free or reduced-price school lunch.

The rate of families hovering just above poverty has not changed much in almost half a century, the census said. About 14.7 million Americans lived in near poverty in 2012, or 4.7 percent of the population. That was a decrease from 6.3 percent in 1966. In contrast, the share of the population living below the poverty threshold has fluctuated between 11 percent and 15 percent in the same period.

The rate appears to have been so stubbornly stable because almost every year, just as some people transition out of near-poverty, a more or less equal number join it, the report said.

Austin Nichols, a research associate at the Urban Institute who specializes in income and social insurance programs, said government intervention played a big role in keeping more families out of poverty or near-poverty in a decade that saw two significant recessions.

“Usually, a third of those who are unemployed get unemployment insurance, but during the (last) recession it was two-thirds,” he said. “That mitigates some of the huge losses in income people experienced. Unemployment insurance doesn’t make you whole again, but it might keep you out of poverty and near-poverty.”

The relative stability of both rates suggest how difficult it is to tackle poverty over the long run, particularly as structural changes in the economy have decimated many blue collar jobs that once were the backbone of the middle class. Poverty and near-poverty have declined significantly among the elderly. and numerous programs exist to help poor children. But the decline has been scant in the working age population since 1966.

“It’s about young parents, a lot of them from non-traditional American families like recent immigrants and single mothers,” Nichols said. “Government policies seem to work to keep the poverty rate stable, but they’re not making huge improvements.”

The census report showed women had a higher rate of living in near poverty, 5.1 percent, than men did at 4.4 percent. In 1966, there was little difference in the two rates, each being a little above 6 percent.

The biggest decline over the last half century has been among African Americans. In 1966, 11 percent lived just above poverty, compared to 6.3 percent now.

The Washington area has a smaller share of the near-poor than the national average. In the District, 4.2 percent are considered near-poor, compared to 3.7 percent in Virginia and 2.9 percent in Maryland.