Home Health Certificate

I have a patient that was seen in a nursing home in Pa. that was discharged to a family member's home in Delaware. I am trying to bill for a Home health certificate so a nursing facility in Delaware can go to the home & care for this patient. I am billing G0180 with office as place of service. This is how I bill all other home health certificates without any problems. Medicare is denying this claim for invalid information on where the services rendered. Could this be because we are in Pa & the home health agency is out of state?

I have seen

denials when I billed the day I got the form and signed it (which was 2 weeks after admission to home care) and it just so happened that the patient was readmitted to the hospital after being home a week so the date I used corresponded in their system to an inpatient day so they denied it. I rebilled with the first home care day and got paid.