Based on information supplied by a spokesman for the National Forum Foundation, an article Thursday incorrectly reported the number of U.S. families entitled to child-support payments. According to the author of the group's study on child support, in 1983, 8.4 million female-headed families were entitled to support payments. Of them, 1 million received $200 or more each month throughout the year, 1.9 million received as much as $200 a month and the rest received no payments.

States are not doing their part to carry out a new program designed to improve the collection of child-support money, a Washington research foundation said yesterday.

Juanita Duggan, who edited the report by the nonpartisan National Forum Foundation, said there is not a state in "this country that is helping all the single parents it should. No state is even coming close."

The study said that last year more than 7 million women were entitled to child-support payments from absent fathers, but that only about 1 million received any of the money.

In the District, only about 3,000 of 48,000 families entitled to support received it last year, according to the report. In Virginia, about 14,700 families out of 202,300 entitled to support received it, and in Maryland 42,900 families out of 176,900 received it.

Congress passed legislation last year giving states new authority to crack down on parents who avoid their support obligations, including withholding tax refunds. It required each state to create a commission on child support and report its findings by this October.

Duggan said Congress' job essentially is done and "now it is up to the states. They are in the best position to help citizens who are entitled to child support, ordered in state courts under state laws."

Using Agriculture Department figures, the report suggested that states set goals of collecting $5 a day from absent parents for each child.

A spokesman for the Health and Human Services Department said she had not seen the report but added that the system should improve because of the legislation passed last year.

Wayne Dixon, the study's author, said that by forcing absent parents to share the responsibility for their children, "the taxpayer will benefit because fewer individuals will be dependent on Aid to Families With Dependent Children, Medicaid, food stamps, public housing assistance" and other welfare programs.

"In l984, illegitimacy, desertion and divorce caused more than 2.4 million mothers to seek help from state child support programs," Dixon said.

Compared to the 50 states, the study said, the District in 1982 had the highest percentage of births by single women: 53.3 percent. Maryland was third with 27 percent and Virginia was 19th with 19.7 percent.