CMS says you'll get paid for observation.
D014487:Centers for Medicare and Medicaid Services, U.S.; D002637:Chest Pain / Q000175:diagnosis* / Q000191:economics; D006801:Humans; D006278:Medicare; D019370:Observation; D018710:Pain Clinics / Q000191:economics*; D011445:Prospective Payment System; D014481:United States