Coding for Residents
Updated: Jan 30, 2019
I know. You didn't go to medical school so you could learn a diabolical accounting system, and no alphanumerical code could capture the worth of what you do all day. Unfortunately, unless and until the healthcare reimbursement system changes, this is what we have to work with. So you might as well roll up your sleeves and decide to make the system work for you.
This is what I wish I had learned about coding and billing as a resident, and I will start at the very beginning. If this is too basic for you, revel in your own glory and wait for future installments.
First, some terminology:
Every diagnosis or description is given an International Classification of Disease (ICD) code. You use ICD codes both to document patient care and to justify all the services and treatments you provide. We are currently in ICD-10.
CPT (Current Procedural Terminology) codes describe every aspect of patient care, including office visits, procedures and tests. Most of the CPT codes used in primary care are in the "Evaluation and Management" (E/M) category. There is an additional set of codes, called HCPCS (pronounced "hickpicks") that supplement the CPT codes.
Every CPT code is assigned an RVU (Relative Value Unit) which has three components: the physician's work, the practice expense and the malpractice cost. Often physician productivity is measured by only the component of the RVU assigned to physician's work, the "work RVU" or wRVU.
Next, how these three codes work together:
Every CPT code for every patient encounter must have an associated ICD10 code; if the diagnosis is unclear, the ICD10 code might be a descriptor such as "fever" or pertinent history such as "family history of Factor V Leiden". This is how you justify the work you did, the tests you ordered etc. Insurance companies then reimburse you (or your employer) based on the number of RVUs each encounter represents using a "conversion factor", which is a specific dollar amount per RVU.
Now, some finer points:
Certain procedures are assumed to have multiple components. These components are all included, or "bundled" under that CPT code. This means you cannot bill for each separate component for the same patient on the same day. For example: in primary care, a routine health maintenance visit is assumed to include a comprehensive physical exam and counseling on healthy habits (among other things). You cannot bill for these two items separately on the same visit.
Sometimes, it is appropriate to "unbundle" charges. If you address an acute condition during a health maintenance exam, for example, you can bill for both a preventive visit AND an acute visit and attach a CPT modifier (-25) to the routine visit code to show that the service was separate. You can only unbundle if the additional service was appropriate, medically necessary and you have appropriate documentation. More on this here.
Medicare sets their conversion rate every year, and most - but not all - insurance companies use that rate or something close to it. RVU x conversion factor should = how much you collect, but the reality is more complicated. Insurance companies can dispute charges, refuse to pay certain charges as a matter of policy, or pay only partially. Most insurance companies follow Medicare's lead but not all - and even those who do make exceptions. And to add to the confusion, all of this can and will change - we just don't know how.
Your most important job as a resident is to learn the practice of medicine. While you are at it, you can learn the business of medicine in the same way - by asking your attendings for advice and critique as you learn to code - so that when you graduate you are ready to hit the ground running.
Next: Work Harder, Not Smarter: Coding Acute Visits