Medicare paid one provider $4,701 for a drug administration that should’ve brought $3,462. The provider used the wrong billing code, producing a $1,239 overpayment. A federal watchdog caught it.
Taxpayers should expect the payment system to catch mistakes like that before the money leaves; hospitals should expect clear instructions about submitting accurate bills, while both expectations seem reasonable for a program entrusted with paying for Americans’ medical care.
An October watchdog report identified 160,918 outpatient-drug claim lines whose procedures and drug codes didn’t match federal reference files. Medicare paid $27.6 million for those entries, covering services from April 2024 through March 2025. The review didn’t determine total overpayments or underpayments.
Nobody should turn that $27.6 million into a theft headline. Taxpayers deserve an accurate accounting of government mistakes, including the limits of what investigators established. Inflating the findings would make a legitimate oversight problem easier to dismiss.
Investigators checked 30 selected entries and found incorrect procedure codes in 24. Providers cited clerical mistakes and billing-system problems. The sample wasn’t statistically representative. Some coding errors didn’t affect payment because the facilities used different reimbursement systems.
Our analysis of 160,918 claim lines for outpatient drugs billed with procedure codes that did not match the procedure codes associated with the drug codes in the crosswalk files showed:
- Six procedure codes were associated with 62 percent of these outpatient drugs.
- Two provider types (critical access hospitals and short-term acute-care hospitals) billed for 99 percent of these outpatient drugs.
- One short-term acute-care hospital billed for 7 percent of these outpatient drugs.
We identified two potential vulnerabilities related to CMS’s and MACs’ oversight of providers’ billing of drugs:
- They did not have system edits to ensure providers used the correct procedure code when billing for outpatient drugs.
- Their provider education activities did not address billing for drugs using procedure codes that match those associated with the drug codes in CMS crosswalk files.
An accusation of widespread criminal conduct would outrun this evidence. A demand for stronger payment controls fits.
CMS and its contractors lacked automated checks matching the two codes. Provider education also lacked sufficient detail on how to match them. CMS supplied technical comments on the draft; the final brief made no specific recommendations.
We issued a draft of this data brief to CMS. CMS furnished technical comments, which we addressed as appropriate.
We conducted this performance audit in accordance with generally accepted government auditing standards. Those standards require that we plan and perform the audit to obtain sufficient, appropriate evidence to provide a reasonable basis for our findings and conclusions based on our audit objectives.
We believe that the evidence obtained provides a reasonable basis for our findings and conclusions based on our audit objectives.
I’d like to see the agency answer a few practical questions. Which mismatches can it flag automatically? Which require a review of medical records? How will it prevent a new safeguard from delaying legitimate payments? Who will report whether the changes work?
Accurate billing matters to providers and taxpayers. Overpayments require correction, while underpayments can leave a provider short. Either outcome creates work that getting the bill right could prevent.
A sensible response should test any proposed fix, clearly explain the rules, and measure the results. Adding paperwork without improving accuracy would give everyone more work while leaving the underlying problem unresolved.
Patients shouldn’t have to understand federal billing codes to expect competent administration. Nor should taxpayers need an inspector general’s report to learn whether the payment system checks information it already has.
Medicare demands accuracy from the people submitting its bills. It should demand equally useful safeguards from the people processing them.