Federal officials overseeing a fast-growing $10 billion children’s disability program have failed to follow up on the progress of 400,000 beneficiaries with behavioral, learning, and mental disorders, allowing families to receive monthly cash benefits for years even if their children’s condition has improved, according to a draft report from the Government Accountability Office obtained by the Globe.

The report by the investigative branch of Congress estimated that the Social Security Administration, which runs the Supplemental Security Income program, might save $9 for every $1 it spends on disability reviews by determining that some children no longer qualify. Reviews are typically required once every three years for the 1.3 million children now receiving benefits, a record high.

Investigators also cited many instances of incomplete data or highly subjective factors being used to evaluate children with mental impairments, who now account for more than half of all cases. Though the program rejects half of all claims for disability payments, it has over the past decade seen a surge of awards in three categories - attention-deficit hyperactivity disorder, speech delay, and autism spectrum disorders - particularly for young boys.

Treatment with psychotropic drugs, which alter mood and behavior, does not appear to play a pivotal role in awarding benefits, the report said, despite investigators’ findings that there is “a perception among some parents that medicating their child would result in an award of benefits.’’

In fact, children who were on such drugs were more likely to be denied than approved, sometimes because the psychiatric medications, particularly for ADHD, were viewed as improving their condition.