Dozens of federal programs to help Americans with disabilities find jobs are fragmented and overlapping, potentially making services for this vulnerable population inefficient and wasteful, government auditors reported. Even with at least $4 billion a year allocated by nine federal agencies to employment programs, the government does little to measure whether the efforts are putting the disabled to work, how long those workers stay employed and whether they are satisfied with their jobs, the Government Accountability Office found. The report, “Employment for People With Disabilities,” is one in a series of audits by the congressional watchdog this year that have pointed out duplication and waste in federal programs. President Obama pledged to reduce this kind of overlap in last year’s State of the Union address. But in an unwieldy bureaucracy, progress can be slow.