Guidelines for Coding Pathology and Laboratory Services

Comprehensive Guidelines for Coding Pathology and Laboratory Services

Medical coding for pathology and laboratory services is a specialized area within medical coding that requires attention to detail and an understanding of complex diagnostic procedures. Proper coding is essential for accurate billing, compliance with regulations, and ensuring that healthcare providers receive appropriate reimbursement. This blog provides a comprehensive guide to coding pathology and laboratory services, including best practices, common pitfalls, and key considerations.

Pathology Reports
Coding Clinic has clearly stated that in an inpatient setting, coders are not able to assign codes based on the pathology report without physician confirmation of the diagnosis.

Laboratory Results
Additional diagnoses should not be arbitrarily added on the basis of an abnormal laboratory finding alone. To make a diagnosis on the basis of a single lab value or abnormal diagnostic finding is risky and carries the possibility of error. The physician must diagnose the patient.

A value reported either lower or higher than the normal range does not necessarily indicate a disorder. Many factors may influence the value of a lab study. These include the method used to obtain the sample, the collection device, the method used to transport the sample to the lab, the calibration of the machine that reads the values, and the condition of the patient.

It is the physician’s responsibility to document the patient’s diagnosis. In the inpatient setting, a diagnosis based on an abnormal laboratory result or diagnostic test should not be determined by someone other than a physician. The physician must document the diagnosis in the medical record before it can be coded. In addition, it is not adequate for a physician to use only arrows (↑ or ↓) to indicate a diagnosis, even if treatment was given for that condition. The physician must document the actual diagnosis.

In outpatient coding, coders are allowed to code from the pathology and radiology reports without the attending/treating physician confirming the diagnosis. The pathologist and radiologist are physicians and as long as they have interpreted the tissue or test then it may be coded. Coders should code to the highest degree of certainty at the time of coding. If there is a final report available at the time of coding, which is authenticated by a physician, it may be used to code from.

Outpatient coders may not code from laboratory reports unless the physician has made a notation regarding the findings with a diagnosis from the laboratory results.

Abnormal findings (laboratory, x-ray, pathologic, and other diagnostic results) are not coded and reported unless the physician indicates their clinical significance. “There can be a bone of contention here because technically, radiologists and pathologists are physicians.

• Services are either carried out by automated means or manually.
• If a specific technique is not mentioned, use an automated technique code.
• You don’t need to use Modifier 51 for multiple laboratory tests

Path & Lab modifiers:

• Modifier 90: Reference Lab; assigned when the lab specimen was sent to a reference lab; however, the billing agreement is that the provider’s office will bill for the service
• Modifier 91: Repeat Procedure; assigned when an identical pathology service is repeated (this must be the same CPT code)
• Modifier 92: Alternative Lab Platform Testing; assigned when the testing is performed utilizing an alternative lab platform

There are two types of general tests in Path and Lab: qualitative and quantitative. Quantitative tests how much of a certain thing is in the body (say, calcium or alcohol), while qualitative tests for the presence of a substance, period.

Path and Lab codes are measured by the number of tests performed, and not the results of the test.

Path & Lab terminology:

Quantitative: Quantitative measurements quantify the amount of a substance present in the system. This might include measurements such as cholesterol levels or the concentration of a drug in the bloodstream.

Qualitative: Qualitative testing determines whether a particular substance is present or not, or analyzes cellular characteristics like shape and structure, such as morphology. For instance, it can tell you if a specific drug is detected in your system.

Gross Examination: Gross examination involves visually inspecting a specimen or substance without the aid of a microscope or other tools.

Panel: A panel is a set of tests that are conducted together to assess a person’s overall health. To bill for a panel, all the tests included in it must have been done. If more than one panel is tested along with another test, only one panel can be billed, and each additional test will be billed separately. 

What is a CLIA?

CLIA stands for Clinical Laboratory Improvement Amendments. Under CLIA, healthcare providers obtain permission from the Center for Medicare and Medicaid Services to perform simple tests, such as a urine pregnancy test, in their office. These tests are known as CLIA-waived tests and are identified with the modifier QW. 

1. Understanding Pathology and Laboratory Services

Pathology Services: These services involve the examination of tissue samples, fluids, and other specimens to diagnose diseases and conditions. Key aspects include:

• Histopathology: Examination of tissue samples under a microscope to identify abnormalities.
• Cytopathology: Study of individual cells to diagnose diseases.
• Molecular Pathology: Analysis of DNA, RNA, and proteins to understand disease mechanisms.

Laboratory Services: These involve testing of blood, urine, and other bodily fluids to diagnose and monitor health conditions. Common tests include:

• Clinical Chemistry: Analyzing chemical components in blood and other fluids.
• Hematology: Studying blood and blood-forming organs.
• Microbiology: Identifying infectious agents such as bacteria, viruses, and fungi.

2. Key Coding Guidelines

A. Use of CPT Codes

1. Code Selection:
   • Histopathology: Use CPT codes from the 80000 series. For example, 88300–88399 covers various pathology services.
   • Cytopathology: CPT codes from the 88100 series are used, such as 88104 for a cytopathology exam.
   • Laboratory Tests: CPT codes from the 80000–89300 series cover various laboratory tests, including chemistry, hematology, and microbiology.
2. Detailed Descriptions:
   • Ensure the description of the pathology or laboratory service matches the CPT code selected. For example, 88305 covers a general surgical pathology examination, while 88342 is used for immunohistochemistry.

B. ICD-10 Codes

1. Diagnosis Matching:
   • Select ICD-10 codes that accurately reflect the patient’s diagnosis as indicated in the pathology or laboratory report. The diagnosis should be specific and relevant to the tests performed.
2. Documentation Requirements:
   • Ensure that documentation in the medical record supports the diagnosis and justifies the necessity of the pathology or laboratory tests.

C. Bundling and Unbundling

1. Bundling:
   • Some pathology and laboratory services are bundled. For instance, a comprehensive pathology examination may include several procedures under a single code. Refer to the CPT code descriptors and guidelines for bundling rules.
2. Unbundling:
   • Avoid unbundling services that should be reported under a single comprehensive code. Unbundling can lead to claim denials and compliance issues.

D. Special Considerations

1. Preventive Services:
   • For preventive services, such as screening tests, use appropriate codes and verify that they are covered under preventive care guidelines.
2. High Complexity Testing:
   • For high-complexity laboratory tests, such as genetic testing, ensure proper use of codes that reflect the complexity and specific nature of the tests.

3. Common Pitfalls and Best Practices

A. Inaccurate Coding:

• Verify that codes accurately reflect the procedures performed and the diagnosis. Miscoding can lead to claim denials and compliance issues.

B. Insufficient Documentation:

• Ensure that all required documentation, including detailed test results and interpretations, is complete and supports the coding used.

C. Understanding National Correct Coding Initiative (NCCI) Edits:

• Familiarize yourself with NCCI edits that may affect coding for pathology and laboratory services. These edits help ensure appropriate coding practices and prevent improper billing.

D. Staying Updated:

• Regularly review coding updates and changes to CPT and ICD-10 codes. Staying current with changes ensures accurate and compliant coding practices.

Accurate coding for pathology and laboratory services is crucial for proper reimbursement and compliance. By adhering to coding guidelines, ensuring detailed and accurate documentation, and staying informed about changes in coding practices, medical coders can contribute to efficient billing processes and support the financial health of healthcare providers.

Adopting these guidelines helps mitigate the risk of claim denials and audits, ultimately benefiting both patients and providers.