There are plenty of reasons why Medicare often fails to stop questionable payments up front. To protect law-abiding doctors and hospitals—the vast majority—Medicare is required to pay nearly everybody within 30 days. Medicare says it is reluctant to suspend payments to providers who may have made honest mistakes, out of concern that beneficiaries might go without needed treatment. Law-enforcement agencies and Medicare contractors, overwhelmed by the sheer volume of Medicare fraud cases, can't investigate and prosecute them all. Sometimes, prosecutors and investigators ask Medicare to keep paying so as not to tip off targets of an investigation.
But a central problem is that Medicare hasn't fully exploited its most valuable resource: its claims database, a computerized record of every claim submitted and every dollar paid out.