Now that you know what ICD-9-CM is used for, what it looks like, and how it’s organized, it’s time to look at some more practical examples of this important code at work.
The coding process actually begins with the medical report. The medical report provides the coder with an immense amount of information, including the patient’s demographic info, their medical history, the patient’s present symptoms, the doctor’s diagnosis, the procedures performed by the doctor to ascertain or confirm the diagnosis, and the prescriptions or treatments, if any, recommended by the doctor. The medical report is the full documentation of the patient’s visit.
All of medical coding is derived from this important document. For the sake of simplicity, we’re going to focus only on the symptoms and diagnosis portion of the report, but we’ll return to this in our courses on procedure coding.
The Coding Process
After reading over the medical report, a coder will take notes and abstract the information in the report. Most physicians or providers will list the patient’s symptoms and then give their diagnosis in a straightforward, direct manner. Let’s look at a quick, simplified example of a medical report.
Patient is 28-year-old Caucasian male. Self-reported height and weight 1.85m and 85 kg. Smoker. History of asthma and breathing problems as a child, though none recently.
Patient presents with hacking cough, difficulty breathing, production of mucus, fever. Suspected diagnosis of acute bronchitis. Pulmonary function test performed with spirometer. Diagnosis confirmed.
Prescribed bed rest and low dose of anti-inflammatory drugs (prednisone) to patient.
There’s a lot information here! There’s the patient’s height, some of his medical history, his symptoms, the procedure the doctor performed, the prescription and more. Since, however, we’re looking at diagnosis codes, we have to winnow down what we’re looking for.
In the case of a positive diagnosis, we don’t code any symptoms. That means the only diagnostic code we’re using is the one for acute bronchitis (466.0). That means you won’t code for fever, hacking cough, or mucus production. You only code for symptoms when a healthcare provider is unable to make a clear, definitive diagnosis.
You might look at the report and also see “history of asthma and breathing problems,” but since those conditions did not directly affect the patient’s visit this time, we don’t always have to code them.
Now’s a good time to step back and take another look at some of the guidelines and rules of using ICD-9-CM.
In the previous course, we talked a little about the format of the code set and its guidelines for use. To recall, the guidelines, or conventions, include:
- Brackets [ ]
- Parentheses ( )
- “See Also”
- “Code First”
- “Use Additional Code”
- “In Diseases Elsewhere Classified”
You can think of these guidelines and additional bits of information as instructions for the code. They are typically listed below the code and tell the coder whether the code they are looking at is the right one.
Let’s return to our bronchitis example. If we look in the ICD-9-CM manual, we’d see the code we’re looking for, 466.0. Below that, we’d also see an “Excludes” note. Under that note, you’d find the phrase “acute bronchitis with chronic obstructive pulmonary disease (491.22).”
Likewise, you’d also find an Includes note below the acute bronchitis code, which would include the following information:
- Bronchitis, acute or subacute
- With tracheitis
- Croupous bronchitis
- Tracheobronchitis, acute
These notes perform two functions. One, if you were trying code acute bronchitis with chronic obstructive pulmonary disease, and flipped to just acute bronchitis, you’d know to look elsewhere. This might seem like a minor distinction, but this can make a huge difference on an insurance claim. So, the “Excludes” note gives you a warning about what not to use.
Similarly, the “Includes” note confirms the coder’s success. By looking at the “Includes” note, a coder can double-check that the code they’re looking at is the correct one. If, however, the term you’re looking for isn’t in the “Includes” section, you may have to double back and look for a different code.
Let’s look at another example, this time looking at manifestations and conditions.
Here’s the (again simplified) medical report.
Patient is a 62-year-old African American female. Self-reported height and weight 1.65m and 75kg. has had diabetes mellitus type ii for 6 years. On a program of Metformin with insulin injections.
Patient presents with nausea, foaming/frothy urine, headache, and fatigue. Suspected diagnosis of some diabetic nephropathy (kidney disease). Tested for heightened protein in urine via microalbuminuria test. Test results positive. Performed retinopathy, which confirmed diagnosis of Kimmelstiel-Wilson syndrome (kidney disease).
Discontinued program of Metformin and prescribed program of perindopril. Dialysis distinct possibility in future.
Before we go any further, we should reiterate that this and all of the other medical report examples listed in these courses simplified for the ease of understanding. Many lab reports, for example, take days to complete, and medical reports for conditions as severe as kidney disease are often longer and significantly more complicated.
In other words, don’t expect medical reports to be this cut-and-dry.
With that warning out of the way, let’s look at this example. We’re looking for the doctor’s diagnosis, which is listed as Kimmelstiel-Wilson syndrome, a chronic kidney disease.
We’ll start in the alphabetic index. If we turn to the ‘K’ section and find Kimmelstiel-Wilson syndrome, that sends us to code 581.81, for “Nephrotic syndrome in diseases classified elsewhere.” That “diseases classified elsewhere” should be an immediate tip-off: that’s the phrase that’s used to describe a manifestation code, meaning it’s a manifestation of another condition.
Below code 581.81, we’d find the note “Code First.” Below that note, we’d see a number of underlying diseases, including amyloidosis, diabetes mellitus, malaria, and a few other conditions.
If you’ll recall from the last course, the “Code First” convention instructs coders to code the underlying condition before the manifestation of the disease. In this example, the Kimmelstiel-Wilson syndrome is how the patient’s diabetes manifests. In other words, the type II diabetes mellitus is the condition, and the Kimmelstiel-Wilson syndrome is the manifestation.
So now we’d look at diabetes mellitus. When we turn to the code (250), we see a number of subcategories that correspond to several types of manifestations. We’d look through and find 250.4, for “diabetes mellitus with renal complications.” Since we’re coding a diagnosis that deals with kidney disease, this is the correct code to use. We’d also code down to the subclassification (remember that we have to code to the highest level of available specificity!). Let’s take a look at the code tree below. We’ve once again bolded the correct category, subcategory, and subclassification.
250 Diabetes Mellitus
- 250.0 Diabetes mellitus without complications
- 250.4 Diabetes mellitus with renal manifestations
- 250.40 – type II or unspecified type, not stated as uncontrolled
- 250.41 – type I [juvenile type], not stated as uncontrolled
- 250.42 – type II or unspecified type, uncontrolled
- 250.43 – type I [juvenile type], uncontrolled
Because the patient is on a medical regimen (from the medical report: “patient… on a program of Metformin”), we would say their diabetes is “not stated as uncontrolled.”
So, we’d code this underlying condition first, and then we’d code for the manifestation: 581.81, “nephritic syndrome in diseases classified elsewhere.” Essentially, what this says is that the patient has a kidney disease that is the direct result of their type II diabetes mellitus.
In certain cases, you may find something missing from a medical report. This could be a procedure, or it could be an incomplete diagnosis. (Recall that, in cases where a doctor can’t come to a positive diagnosis, a coder may code the patient’s symptoms). If a the listed diagnosis does not match up with the procedure or procedures performed, it’s up to the coder to contact the provider to clarify the report. This can be especially difficult in medical reports on large, complicated procedures. There may also be multiple diagnoses listed in a medical report. A coder has to list every diagnosis (or set of symptoms) that’s directly related to a procedure performed by the provider.
Remember, ICD codes are used to demonstrate medical necessity in insurance claims. They justify the processes performed by the doctor. If you read a report and a certain procedure is not justified by a doctor’s diagnosis, you must contact the doctor to get clarification.
The final step of the coding process is the submission of codes. In the past, this was done via paper forms, but today almost all medical codes are submitted via a software system like Epic. We’ll cover this a bit more in Course 2-14. For now, just know that when the coder has fully coded the medical report, they submit these codes to the medical biller (or medical billing agency). The medical biller then uses these codes to make the claim.
Now you know what ICD-9-CM is, and how to use it. In the following two courses, we’ll talk about ICD-10-CM, which is due to replace ICD-9-CM in October of 2015. These code sets shares a lot of similarities, but have a few critical differences.