STUDY AFTER STUDY has documented the fact that millions of poor children in America receive inadequate health care or, in too many cases, no health care at all. Studies also have shown that the lack of early health care reduces the chance that those children will do well in school and go on to become productive members of society. That was what prompted the creation a decade ago of the federal Early Periodic Screening, Diagnosis and Treatment Program. Its purpose was to provide, through state health agencies, checkups and care to 13 million children eligible under the Medicaid program.

From the beginning, however, the program worked poorly. According to government officials, nationally fewer than a quarter of the eligible children are checked for childhood diseases and for other health problems. In Maryland, Virginia and the District, the number of children examined varies from 9 to 20 percent of those eligible. Yet the program's limited achievements, it seems to us, only underscore the compelling need to improve and broaden the effort.

Congress can do that quickly by passing a child health assessment bill before it recesses. Such a bill would do more than change the name of the federal effort. It would extend the program's benefits to an additional million children. The appropriate House and Senate committees, after a lengthy review, have produced somewhat different measures. Either is preferable to the curent program. Both require states to serve more poor children by enrolling more doctors, hospitals and health clinics in the program. Both would channel more federal money to the states. And both contain regulations intended to improve federal administration of the program. The proposed changes would increase the current program's $200 million budget by half. In our view, that is a small price to pay for the benefits this program could bring to children in need.