I bill for HH inital certifications, G0180, to Medicare Palmetto GBA here in CA and I have no problem getting paid. Just make sure that your DX matches the first DX on the Plan of Care, your DOS should be the start of care date, POS must be 11 for office and the final thing is that you must put the HHA provider number in Box 23 (this is where prior auth numbers usually go) of the CMS 1500. The HHA provider number is in the upper right hand corner of the Plan of Care.