99396
99396 is a CPT code, not an ICD9 code. The ICD9 code you use will depend on the condition or reason for the visit.
99396
CPT Code 99396 -Periodic comprehensive preventive medicine reevaluation and management of an individual including an age and gender appropriate history, examination, counseling/anticipatory guidance/risk factor reduction interventions, and the ordering of laboratory/diagnostic procedures, established patient; 40-64 years.
99490 is the highest CPT code. 99999 does not exist. It is not a valid CPT. Sorry.
As of Jan 2012, code 73542 is an invalid CPT code.
AS far as I could tell from the CPT code book that is not a valid code
magnesium level
What is proc code 58970
CPT Code 99223- Initial hospital care, per day, for the evaluation and management of a patient.
Total carbamazepine level
one of two types of cpt codes. stand alone codes give a full description