Vol. 11 •Issue 24 • Page 8
ICD-9-CM Coding for Diagnostic Tests
The Centers for Medicare and Medicaid Ser-vices (CMS) has issued guidelines on ICD-9-CM diagnosis codes for diagnostic tests, and many of the examples included in their instructions are focused on services provided by radiologists. Transmittal AB-01-144 (September 26) includes information on reporting diagnoses for diagnostic tests for inpatients and outpatients in facilities and physician offices.
There is a reason CMS issued the transmittal links back to the Health Insurance Portability and Accountability Act (HIPAA). In HIPAA, Congress designated the ICD-9-CM coding system and the Official ICD-9-CM Guidelines for Coding and Reporting, which the American Hospital Association (AHA) publishes, as one of the code sets that must uniformly be used by the health care entities covered by HIPAA. The American Medical Association’s (AMA) Coding Clinic for ICD-9-CM confirms the long-standing ICD-9-CM guidelines, and CMS has officially adopted them as well.
Although many professional coders already know this, CMS makes it clear that physicians must report diagnoses based on test results and assign ICD-9-CM codes to the “highest degree of specificity.” The transmittal also includes information on the following:
•Determining the appropriate primary ICD-9-CM diagnosis code for diagnostic tests ordered due to: 1) signs and/or symptoms and the reason for the test, and 2) in the absence of signs and/or symptoms (e.g., screening tests)
Signs and/or Symptoms
If a diagnosis has been confirmed based on test results, the interpreting physician should code that diagnosis. If the signs and/or symptoms that prompted the test order are not fully explained or related to the confirmed diagnosis, they may be reported as additional diagnoses.
For example, a patient is referred to a radiologist for an abdominal CT scan with a diagnosis of abdominal pain. The scan reveals an abscess. The radiologist should report a diagnosis of “intra-abdominal abscess.”
If the test had not provided a diagnosis or the result was normal, the interpreting physician should code the sign(s) or symptom(s) that prompted the treating physician to order the study. For example, a patient is referred to a radiologist for a spine X-ray due to complaints of “back pain.” The radiologist performs the X-ray, and the results are normal. A diagnosis of “back pain” should be reported because it was the reason for the test.
If the results are normal or non-diagnostic, and the referring physician records a diagnosis preceded by words that indicate uncertainty (e.g., probable, suspected, questionable, rule out or working), then the interpreting physician should not code the referring diagnosis. Rather, the sign(s) or symptom(s) that prompted the study would be reported. Do not report diagnoses labeled as uncertain as they are unconfirmed.
For example, a patient is referred for a chest X-ray with a diagnosis of “rule out pneumonia.” The radiologist performs a chest X-ray, and the results are normal. Report the sign(s) or symptom(s) that prompted the test (e.g., cough).
Reason for the Test
The physician who orders the test must be the one treating the beneficiary and must provide diagnostic information with the order. The Medicare Carriers Manual (MCM) states that an order may be a written document signed by the treating practitioner that is hand-delivered, mailed or faxed. It also may be a telephone call or an e-mail from the treating practitioner or his/her office. In the case of a phone call, both parties must document the telephone call in the medical records.
CMS states that lack of diagnostic information at the time of a test should be “rare.” If the referring physician is unavailable to provide the diagnosis, it is appropriate to ask the patient for it or obtain it from the medical record. However, make an attempt to confirm that information with the referring physician.
Incidental findings should never be listed as primary diagnoses but may be reported as secondary diagnoses. Co-existing conditions also may be reported as additional diagnoses.
For example, a patient is referred to a radiologist for a chest X-ray because of wheezing. The X-ray is normal except for scoliosis and degenerative joint disease of the thoracic spine. The interpreting physician reports wheezing as the primary diagnosis because it was the reason for the visit. The other findings may be reported as additional diagnoses.
When a diagnostic test is ordered in the absence of signs and/or symptoms, the interpreting physician should report the reason for the test (e.g., screening) as the primary ICD-9-CM diagnosis code. The test re-sults, if reported, may be recorded as additional diagnoses.
Focus on “Specificity”
The phrase “code to the highest degree of specificity” is a key one in ICD-9-CM coding. It means to assign the most precise code, such as the one that most fully explains the narrative description of the sign or symptom that prompted the order or the diagnosis that resulted from the test.
For example, a chest X-ray reveals a primary lung cancer in the left lower lobe. The interpreting physician should report the ICD-9-CM code as 162.5 for malignancy of the left “lower lobe, bronchus or lung,” not the code for a malignancy of “other parts of bronchus or lung” (162.8) or the code for “bronchus and lung unspecified” (162.9).
Another key coding rule is to report the correct number of digits. The rule of thumb is to assign the three-digit codes only if there are no four-digit codes, and assign four-digit codes when no fifth-digit codes exist in a category.
In summary, this transmittal is a good resource for anyone who must bill for diagnostic tests. n
Jeff Majchrzak is vice president of radiology services for Medical Learning Inc. (MedLearn®), St. Paul, MN.