OIG Report on Claims with G Modifiers

On May 3, 2013 the OIG issued: Medicare Payments for Part B Claims with G Modifiers, assessing how Medicare contractors are processing G modifiers.  The OIG analyzed all Part B claims with GA, GZ, GX, or GY modifiers from 2011 and found that there were “vulnerabilities in how Medicare pays for these claims” resulting in improper payments of claims submitted with G modifiers.   
While we commonly associate G modifiers with services that are going to be denied by Medicare, the use of a G modifier does not always result in an automatic denial.  In fact CMS only currently requires contractors to automatically deny claims with GZ modifiers.  To date, CMS has issued no instruction to contractors regarding how they must process claims with a GA modifier, and CMS allows contractors to deny claims with a GY modifier at their discretion.  The report revealed that claims with G modifiers that should not have been paid were slipping through the cracks because contractors were not properly considering G modifiers and appropriately denying claims. 
While stating that the report did not contain any recommendations, the OIG did state the following:
  • CMS needs to ensure contractors are automatically denying claims with GZ modifiers
  • CMS needs to instruct contractors to automatically deny claims with GY modifiers
  • CMS should decide whether to implement the GX modifier for Part B claims since providers are using it
  • CMS should ensure contractors do not pay for claims with inappropriate combinations of G modifiers 

Again, this report underscores the importance of using appropriate denial modifiers and tracking claims with G modifiers to make sure that Medicare is not improperly paying your agency for a service that should have been denied.  In the event your agency does receive reimbursement for non-covered services, be sure to have a process in place to identify overpayments and to refund them promptly following your MAC's refund guidelines.  Federal law requires that any overpayments be refunded within 60 days of when they are identified.