The ICD-9-CM manual is one of the three main coding manuals, and one of the two that you’ll use the most in your medical coding job (along with the CPT manual). It makes sense, then, that the CPC exam would feature approximately ten questions on this code set.
If you’ve taken all the courses up to this point, you should be readily familiar with ICD-9-CM. We’ll do a quick review regardless.
ICD-9-CM is our diagnostic code set. We use it to describe the injuries, illnesses, and conditions in patients, as reported on the medical reports. In terms of the reimbursement process, ICD-9-CM codes are used to demonstrate medical necessity for medical procedures (which are described using either CPT or HCPCS).
The ICD-9-CM manual is divided into three volumes. The first volume is the tabular index, which groups the codes numerical by similarity. This volume is loosely divided into “chapters,” each of which covers a certain field. The first chapter, for instance, contains codes for infectious and parasitic diseases.
The second volume is the alphabetical index of codes. You can use this volume to look up diagnosis codes by their medical name, or, in certain cases, by their more colloquial term. This is your first point of navigation.
ICD-9-CM codes are three to five characters long and are, with a few exceptions, entirely numeric. The first three numbers of a code is called the category. The category describes the patient’s condition, illness, or injury. In cases where the code is more specific than the general condition, the category is followed by a decimal point and another digit, called the subcategory. The subcategory is sometimes followed by yet another digit, called the subclassification. The subclassification further expands on the information provided by the subcategory.
We can find the correct ICD-9-CM code in either the tabular or the alphabetic index, but we always confirm our codes in the tabular index.
The third and final volume of ICD-9-CM contains procedural codes used by hospitals and other inpatient facilities. We won’t be covering them here.
Let’s move on to the exam and what to expect.
On the CPC exam, you should expect to see ICD-9-CM codes in test case questions: questions that provide a sample medical report, and then ask you to figure out the correct codes for the diagnosis and procedure provided.
You’ll code these questions as you would a normal medical report. You abstract the information, note what needs to be coded, go to the alphabetical index, and then confirm in the tabular.
Once you get to the tabular, you’ll need to pay attention to the notes included with many of the ICD-9-CM codes. These notes include See, See Also, Includes, Excludes, and Code First. If, for example, you’re coding a retinal problem related to diabetes, there will probably be a Code First note under the retinal diagnosis that tells you to code the underlying condition (diabetes) before the present diagnosis.
See and See Also codes are included to direct coders to better or more appropriate diagnosis codes. Includes and Excludes are relatively self-explanatory: they tell the coder if the diagnosis they’re looking for does, in fact, ‘live’ in that code.
These notes are part of the reason why we never code from the alphabetical index. If you skip confirming your codes in the tabular index, you might miss an important note that informs you of a better, more accurate diagnosis codes. Remember, as medical coders, we always want to code to the highest degree of specificity. Your job on the CPC exam will be to select the best possible answer out of the four, so it’s imperative you use the most accurate codes possible.
You should also review the coding guidelines and conventions for ICD-9-CM. These are found in the front of the ICD-9-CM manual, and will inform you of the proper ways of using the code. The notes (See, See Also, Includes, etc) are part of the guidelines and conventions, so you already know a bit about them. Just be sure to read each code carefully and check the notes.
One final note about ICD-9-CM and ICD-10-CM. The American healthcare industry, almost across the board, will upgrade to the newer ICD-10-CM set of diagnostic codes on October 1 of 2015. Up until that point, you’ll still be tested on ICD-9-CM. You may even be tested on ICD-9-CM after the changeover date—the AAPC hasn’t made that clear. As of this writing, however, only ICD-9-CM will be on the exam, and so you should confine your preparation to that code set.