A substantial proportion of people who call the Social Security "800" hotline and are told that a local Social Security office will call them back never receive the followup telephone call, the General Accounting Office reported yesterday.

Critics have claimed that Social Security began the toll-free telephone line in an attempt to save money on personnel and, in effect, has reduced the amount of services available at local offices. The 800 system handles 60 million to 70 million calls annually, the GAO estimated, with about 3 million callers told they will get callbacks.

"It is difficult to to avoid the conclusion that the Social Security '800' system is not a working number, or at least that it is not working very well," said Rep. Andrew Jacobs Jr. (D-Ind.), chairman of the House Ways and Means Social Security subcommittee.

A Social Security spokesman said, "We have not seen the report but, under our procedures, even if people do not make contact through the callback from the local offices, their cases are not dropped. If we don't reach them through a callback, we send them a letter telling them to call the local office and giving them the number."

The GAO findings, based on data from earlier this year, showed that of callers who were instructed to expect a return call at a specific time, 89 percent reported getting the call and being pleased with the help they received.

But people who were not given a specific time to expect a callback were not so well served, the GAO reported.

About 24 percent of those who expected to be called back to arrange for an application for benefits said they never received a call, the GAO reported.

Of those receiving benefits who wanted to be called back to discuss problems, 42 percent said they never received a call. In all cases, the followup did not occur until at least two to three weeks had passed from the date the person initially called 1-800-234-5772.