5.3 Pathology & Laboratory Services
Key Takeaways
- Organ or disease-oriented panels require every listed test in the panel to be performed; otherwise, individual codes must be used.
- Presumptive drug testing identifies the presence or absence of a drug class, while definitive testing identifies the specific drug and concentration.
- Surgical pathology codes (88300-88309) are assigned based on the source of the tissue specimen and the complexity of the examination.
- Quantitative testing measures the exact amount of a substance, whereas qualitative testing merely indicates its presence.
Pathology & Laboratory Services
The Pathology and Laboratory section (80047-89398) provides codes for testing performed on blood, tissue, and other bodily fluids. Coding in this section requires an understanding of the methodology used, the specific substance being tested, and whether the test is qualitative or quantitative.
1. Organ or Disease-Oriented Panels
Panel codes (80047-80081) bundle a specific set of laboratory tests frequently ordered together to evaluate a specific organ system or disease state.
The "All or Nothing" Rule
The most important rule for panel coding is that every single test listed in the panel description must be performed to report the panel code.
- If a Basic Metabolic Panel (80053) requires 8 specific tests, and the lab only performs 7 of them, you cannot report the panel code with a modifier 52 (Reduced Services). Instead, you must report the 7 individual CPT codes for the specific tests performed.
- If the lab performs all 8 tests for the Basic Metabolic Panel plus one additional test (e.g., a magnesium level), you report the panel code (80053) AND the individual code for the magnesium test.
2. Drug Testing
Drug testing codes are divided into two main categories: Presumptive and Definitive.
Presumptive Drug Testing
Presumptive testing is generally an initial screening. It is qualitative, meaning it determines whether a drug or drug class is present or absent in the patient's system.
- These tests are typically performed using relatively simple methods (like a dipstick, cup, or card) or basic immunoassay analyzers.
- Codes are selected based on the testing method used (e.g., direct observation, instrument-assisted), not on the number of drug classes tested. A single code covers the screening of multiple drug classes.
Definitive Drug Testing
Definitive testing is highly specific. It confirms the exact identity of the drug(s) and/or metabolites present and is often quantitative, providing the exact concentration of the drug.
- These tests use sophisticated methods like gas chromatography/mass spectrometry (GC/MS).
- Definitive drug testing codes (often found in the HCPCS Level II manual as G-codes for Medicare, or specific CPT codes) are categorized based on the number of specific drug classes evaluated (e.g., 1-7 classes, 8-14 classes).
Therapeutic Drug Monitoring
Do not confuse drug screening with therapeutic drug monitoring (TDM). TDM (80150-80299) is performed for patients taking prescribed medications (like Dilantin or lithium) that have a narrow therapeutic window. The tests monitor the drug concentration in the blood to ensure it remains at a safe and effective level.
3. Surgical Pathology
Surgical pathology involves the examination of tissue removed from the body to determine a diagnosis (e.g., evaluating a tumor to see if it is benign or malignant).
The codes (88300-88309) are divided into six levels, reflecting the increasing complexity and physician work required to examine the specimen.
The Levels of Surgical Pathology
| Code | Level | Description |
|---|---|---|
| 88300 | Level I | Gross examination only (identifying the specimen without a microscope). |
| 88302 | Level II | Gross and microscopic examination of tissue that is typically normal (e.g., a normal appendix removed incidentally, or a fallopian tube for sterilization). |
| 88304 | Level III | Gross and microscopic examination of tissue with low probability of disease (e.g., a gallbladder, a lipoma). |
| 88305 | Level IV | Gross and microscopic examination of tissue with a higher probability of disease (e.g., a colon polyp, a skin biopsy). This is the most common level. |
| 88307 | Level V | Gross and microscopic examination of complex specimens requiring extensive sampling (e.g., a partial kidney, a lumpectomy for breast cancer). |
| 88309 | Level VI | Gross and microscopic examination of the most complex specimens requiring exhaustive sampling (e.g., a total colon for cancer, a radical mastectomy). |
Coding Rules for Surgical Pathology
- Specimen defined: A specimen is defined as tissue(s) that is submitted for individual and separate attention, requiring individual examination and pathologic diagnosis.
- Multiple specimens: If two separate colon polyps are submitted in two separate containers (labeled Polyp A and Polyp B), you code 88305 twice. If three skin biopsies are submitted in the same container, you generally code 88305 only once, as they are not individually identified.
4. Qualitative vs. Quantitative Testing
Throughout the Pathology and Laboratory section, you will see a distinction between qualitative and quantitative testing.
- Qualitative: Answers the question, "Is it there?" The result is positive or negative.
- Quantitative: Answers the question, "How much is there?" The result is a specific number (e.g., 125 mg/dL).
When a physician orders a test, it is crucial to match the code to the exact nature of the test performed.
A physician orders a Comprehensive Metabolic Panel, which includes 14 specific tests. The laboratory performs only 12 of those tests. How should the laboratory services be coded?
Which type of drug test provides the exact concentration of a specific drug in a patient's system?