Part of the confusion from new physicians is that you are going to be using two or three different sets of codes for billing purposes. The first is the CPT® or Current Procedural Terminology code. This is what we have described above and is what doctors mean when they use the generic term “coding.” It is a number that has been assigned to a specific medical service. All medical services, including surgeries, procedures, office visits, injections, and lab tests have been assigned a CPT code. This numeric code helps keep track of billing. It is much easier for everyone to say “We had two hundred 99213 visits in August” than it is to say “We had four hundred office visits where we provided low-complexity care for patients with 1-3 elements in the history of present illness or 6-11 items in the exam during August..”
The CPT codes associated with the routine medical services of Evaluation and Management (i.e., clinic visits), are also called E&M codes.
ICD codes are different from CPT/E&M codes. ICD-9 means International Classification of Diseases, version 9. They are simply a number assigned to a particular disease. For example, hypertension is 401.9. ICD-9 codes do not have to be specific. For example, 786.2 is cough. The ICD-9 code says nothing about the amount of work you did and is not the same as a CPT code. ICD-9 codes do have a relationship with the billing process and are usually included on charge sheets in some capacity. We will explain this later in more detail.
In some offices, the office staff will help choose the ICD-9 code if you simply write down the diagnosis. Also, many electronic medical records will show the ICD-9 code whenever it shows a particular diagnosis. However, you will still need to know which ICD-9 code to choose. There will often be need for clarification from the billing staff on whether you meant dizziness or syncope or if you can give a more specific diagnosis. Some insurance companies will not pay for a lab test for diagnosis x, but they will for diagnosis y. For now, just know that you will need to understand ICD-9 codes. Like E&M codes, they make life more convenient and streamlined for billing. Whether you like them or not, they are a fact of life. ICD-9 codes are here to stay.
Medical Coding and Billing For Residents 