You need to attach modifier -GW when you bill a hospice patient for non-hospice related diagnosis.
If you see a hospice patient for hospice-related diagnosis, you need to attach a modifier -GV and send this bill to hospice instead of Medicare.
Modifier 07 is used by non-physician providers (hospitals, HHA, PT, hospices, etc) to bill Medicare Fiscal Intermediaries for treating hospice patients with non-hospice related diagnoses.