Coding Ahead
CasePilot
Medical Coding Assistant
Case2Code
Search and Code Lookup Tool
CareerCenter
Medical Coding Job Board
Log in Register free account

Need help choosing the right code?

Ask CasePilot about procedures, modifiers, bundling, and coding guidance.

Try CasePilot

Official Description

Leucine aminopeptidase (LAP)

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 83670 refers to the measurement of leucine aminopeptidase (LAP) levels through a blood test. LAP is an enzyme that plays a crucial role in the maintenance of cells and is primarily found in the liver and small intestine. This enzyme is involved in various metabolic processes, and its levels in the blood can provide valuable insights into liver function and overall health. Elevated levels of LAP may suggest liver damage or dysfunction, which can arise from several conditions, including hepatitis, cirrhosis, and tumors. It is important to note that elevated LAP levels can also be a normal physiological finding during the third trimester of pregnancy, indicating that context is essential when interpreting test results. The test is performed by obtaining a blood sample through venipuncture, which is a procedure that may need to be reported separately. The serum obtained from the blood sample is then analyzed using quantitative spectrophotometry, a method that measures the concentration of the enzyme in the serum, providing precise and reliable results for clinical assessment.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The leucine aminopeptidase (LAP) test is indicated for various clinical scenarios where liver function assessment is necessary. The following conditions may warrant the performance of this test:

  • Hepatitis - LAP levels may be elevated in patients with liver inflammation due to viral or autoimmune hepatitis.
  • Cirrhosis - Chronic liver damage leading to cirrhosis can result in increased LAP levels, indicating ongoing liver dysfunction.
  • Liver Tumors - The presence of tumors in the liver may cause elevated LAP levels, serving as a potential marker for malignancy.
  • Pregnancy (Third Trimester) - Elevated LAP levels can be a normal physiological finding during the third trimester of pregnancy, necessitating careful interpretation in this context.

2. Procedure

The procedure for measuring leucine aminopeptidase (LAP) levels involves several key steps to ensure accurate results. First, a qualified healthcare professional will perform venipuncture to obtain a blood sample from the patient. This involves inserting a needle into a vein, typically in the arm, to draw blood into a collection tube. It is important that this step is performed with proper aseptic technique to minimize the risk of infection. Once the blood sample is collected, it is processed to separate the serum from the cellular components. The serum is then subjected to quantitative spectrophotometry, a laboratory technique that measures the concentration of LAP in the serum. This method involves passing light through the serum sample and measuring the absorbance at specific wavelengths, which correlates with the enzyme's concentration. The results are then analyzed and reported, providing critical information regarding the patient's liver function and potential underlying conditions.

3. Post-Procedure

After the blood sample has been collected and processed, there are generally no specific post-procedure care requirements for the patient. However, it is advisable for patients to remain hydrated and to follow any additional instructions provided by their healthcare provider. The results of the LAP test will typically be reviewed in conjunction with other liver function tests and clinical findings to provide a comprehensive assessment of liver health. Patients may be advised to discuss the results with their healthcare provider to understand the implications and any necessary follow-up actions based on the findings.

Short Descr ASSAY OF LAP ENZYME
Medium Descr LEUCINE AMINOPEPTIDASE LAP
Long Descr Leucine aminopeptidase (LAP)
Status Code Statutory Exclusion (from MPFS, may be paid under other methodologies)
Global Days XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC) 9 - Not Applicable
Multiple Procedures (51) 9 - Concept does not apply.
Bilateral Surgery (50) 9 - Concept does not apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 9 - Concept does not apply.
Co-Surgeons (62) 9 - Concept does not apply.
Team Surgery (66) 9 - Concept does not apply.
Diagnostic Imaging Family 99 - Concept Does Not Apply
CLIA Waived (QW) No
APC Status Indicator Conditionally packaged laboratory tests
Type of Service (TOS) 5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS) T1H - Lab tests - other (non-Medicare fee schedule)
MUE 1
CCS Clinical Classification 233 - Laboratory - Chemistry and Hematology
Date
Action
Notes
Pre-1990 Added Code added.
Code
Description
CasePilot

Get instant expert-level medical coding assistance.

Ask about:
CPT Codes Guidelines Modifiers Crosswalks NCCI Edits Compliance Medicare Coverage
Example: "What is CPT code 99213?" or "Guidelines for E/M services"