ICD-9 vs. CPT Coding

ICD-9 vs. CPT Coding

In the world of medical billing, coding of the medical billing forms actually requires the use of two coding systems, one that identifies the patient’s disease or physical state (the International Classification of Diseases, 9th Revision, Clinical Modification, or ICD-9-CM, codes) and another that describes the procedures, services or supplies you provide to your patients (the Current Procedural Terminology, or CPT codes).

To differentiate between these coding systems, think of it this way: CPT codes describe what services you perform, and ICD-9 codes describe why you do it.

Each service you render to a patient becomes a line on an insurance claim form. Your level of reimbursement is linked to a claim’s CPT codes, you need to record a symptom, diagnosis or complaint (an ICD-9 code) to establish the “medical necessity” of each service. That is the all important documentation you keep hearing about with your medical billing claims. Showing medical necessity basically means that you justify your choice of CPT code by linking it to an appropriate diagnosis by using an ICD-9 code. Up to four ICD-9 codes can be linked to each CPT code on a HCFA-1500 form.

If you choose to outsource your medical billing, this is one less thing for you and your staff to deal with. Your medical billing partner will take care of linking your CPT and ICD-9 codes and making sure they are properly coded for procedure performed. Your medical billing partner knows to code to the highest number of digits to describe each individual patient’s condition. Many payers, including Medicare, will deny or delay payments if you fail to do this, and as simple as it sounds, a huge amount of revenue is lost every year for simply incorrect or inaccurate CPT and ICD-9 codes.

View all Articles by: Melissa Clark, CCS-P