8? 8=Tribal 638 Provider-based Facility
31=SNF
http://www.cms.hhs.gov/PlaceofServiceCodes/Downloads/080409codes.pdf
I believe it's your CPT code. Per Medicare....In the nursing facility setting, the consulting physician or qualified NPP shall use the appropriate Initial Inpatient Consultation codes (99251 – 99255) for the initial consultation service.
http://www.cms.hhs.gov/manuals/downloads/clm104c12.pdf
Page 54
CPT also states to report 99251-99255 for Nursing Facilities