This lists it as a transport if the N number is 900LG. Go to Landings.com and search FARs at the bottom of the page
N-number : N900LG
Aircraft Serial Number : 1036
Aircraft Manufacturer : CANADAIR LTD
Model : CL-600 CHALLENGER
Engine Manufacturer : HONEYWELL
Model : ALF 502 SER
Aircraft Year : 1981
Owner Name : DRM MED ASSIST LLC
Owner Address : 2521 METROCENTRE BLVD
WEST PALM BEACH, FL, 334073106
Type of Owner : Corporation
Registration Date : 17-Jul-2009
Airworthiness Certificate Type : Standard
Approved Operations : Transport
http://www6.landings.com/cgi-bin/nph-search_nnr?pass=193800885&&nnumber=900LG
is it operating under part 91 or part 135?