The finding was one of several ‘challenges’ uncovered in the official review of federal coronavirus aid, reports BBC.
Inspectors said that the rush to deliver the money has contributed to this errors.
Congress has pumped some $2.6tn into the American economy in an effort to shield it from virus slowdown since March.
The Government Accountability Office (GAO) report found that the Treasury Department, did not check death records.
However, some of the tax officials working on the programme said they raised concerns about the risk of erroneous mailings.
The report also warned that the Paycheck Protection Program for small businesses - a low-cost loan fund that accounts for 26% of US pandemic spending - was at "significant risk" of fraud, faulting the Small Business Administration for not cooperating with requests for information about the loans and its plans for oversight.
The inspectors also said that "Because of the number of loans approved, the speed with which they were processed, and the limited safeguards, there is a significant risk that some fraudulent or inflated applications were approved."