Granted, I did not spend a lot of time doing legal research but here is a link that shows that tramadol is a non-scheduled prescription only drug under Federal law. The various states may have differing laws, rules and regulations.

http://www.erowid.org/pharms/tramadol/tramadol_law.shtml

Edited to add the FDA link showing it is RX and not OTC. It is NOT a scheduled (controlled) drug but it IS a regulated, i.e. RX needed to buy it legally. No federal penalty for possession. State laws may vary.

http://www.accessdata.fda.gov/scripts/cder/ob/docs/temptndet.cfm?Appl_No=020281&TABLE1=Rx