Pathology/Lab Coding Alert

Question: What is the correct ICD-9 code for pneumonia if the physician does not specify the infecting organism? We had a physician write "pneumonia" on a hospital patient's chart without specifying the type. I spoke with him, and he said that the patient had Gram-negative bacterial pneumonia. Should I report 482.83?

Texas Subscriber

Answer: If you are coding for the hospital, you must code based on the physician's final written diagnosis, which can usually be found on the discharge summary. If you need to contact the physician for clarification, get the diagnosis in writing.

Before you use 482.83 (Gram-negative pneumonia NOS), you must have documentation for the diagnosis in the medical record. If the physician told you the patient had Gram-negative bacterial pneumonia, you should ask for a written diagnosis, along with supporting diagnostic test results. These might include tests such as Gram stain on a bronchial-washing specimen (87205, Smear, primary source with interpretation; Gram or Giemsa stain for bacteria, fungi, or cell types), a culture of the bronchial specimen (87070, Culture, bacterial; any other source except urine, blood or stool, with isolation and presumptive identification of isolates), and perhaps additional tests for definitive culture identification (87077, Culture, bacterial; aerobic isolate, additional methods required for definitive identification, each isolate). Even if results from these tests are in the patient's chart, you can't code 482.83 unless the treating physician wrote a Gram-negative pneumonia diagnosis on the patient's chart.

The U.S. Office of Inspector General (OIG) scrutinizes pneumonia coding in facilities, so lack of documentation could raise red flags for hospital inpatients. Unlike physician reimbursement, hospitals are paid a specified amount through the diagnostic-related groups (DRGs) based on the diagnosis code used. The OIG's "pneumonia-upcoding project" identifies instances when coders assign viral/bacterial pneumonia diagnosis codes when the condition is not present or is not substantiated by the medical record, resulting in the higher-paying DRG 79 rather than DRG 89. Originally, the project focused on pneumonia that was coded 482.89 (Pneumonia due to other specified bacteria), but the OIG has widened its investigation to include 482.83 also.

Without specific lab tests and physician interpretation identifying the pneumonia-causative organism beyond "bacterial," pneumonia cases should be reported as 482.9 (Bacterial pneumonia unspecified) not 482.83 or 482.89. This less-specific diagnosis code is part of the lower-paying DRG 89.