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

Phosphatase, alkaline; isoenzymes

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 84080 refers to a laboratory test that measures the levels of alkaline phosphatase (ALP) isoenzymes in a blood sample. Alkaline phosphatase is a type of hydrolase enzyme that plays a crucial role in the removal of phosphate groups from various molecules. This enzyme is predominantly found in several tissues throughout the body, including the liver, bile ducts, kidneys, bones, and placenta. The measurement of ALP isoenzymes is significant because elevated levels can indicate various medical conditions, such as bile duct obstruction, Paget's disease, and certain types of tumors like seminomas. Conversely, decreased levels of alkaline phosphatase may be associated with conditions such as hypophosphatasia, Wilson's disease, specific types of anemia or leukemia, and other health issues, including malnutrition and hypothyroidism. The test is performed by obtaining a blood sample through venipuncture, which is a separately reportable procedure. The analysis of the sample is conducted using quantitative enzymatic methodologies, allowing for the differentiation of various isoenzymes, which include ALPI (intestinal), ALPL (non-specific, liver/bone/kidney), and ALPP (placental). This differentiation is essential for accurate diagnosis and management of the underlying conditions associated with abnormal ALP levels.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The alkaline phosphatase isoenzyme test (CPT® Code 84080) is indicated for the evaluation of various medical conditions associated with abnormal levels of alkaline phosphatase. The following conditions may warrant this test:

  • Bile Duct Obstruction Elevated alkaline phosphatase levels may indicate an obstruction in the bile ducts, which can lead to liver dysfunction.
  • Paget's Disease This condition, characterized by abnormal bone remodeling, may result in increased levels of alkaline phosphatase.
  • Seminomas Certain tumors, such as seminomas, can cause elevated alkaline phosphatase levels, necessitating monitoring through this test.
  • Hypophosphatasia Decreased levels of alkaline phosphatase may be observed in this genetic disorder, which affects bone mineralization.
  • Wilson's Disease This genetic disorder that leads to copper accumulation in the body may also result in lower alkaline phosphatase levels.
  • Anemia/Leukemia Certain types of these blood disorders can influence alkaline phosphatase levels, making this test relevant for diagnosis.
  • Postmenopausal Women on Estrogen Therapy Women undergoing estrogen therapy for osteoporosis may exhibit decreased alkaline phosphatase levels.
  • Oral Contraceptive Use Women taking oral contraceptives may also show decreased levels of alkaline phosphatase.
  • Men Following Cardiac Surgery Cardiac surgery may lead to changes in alkaline phosphatase levels in men.
  • Malnutrition or Hypothyroidism Both conditions can result in decreased alkaline phosphatase levels, indicating the need for this test.
  • Children with Achondroplasia, Cretinism, or Severe Enteritis These pediatric conditions may also be associated with altered alkaline phosphatase levels.

2. Procedure

The procedure for measuring alkaline phosphatase isoenzymes (CPT® Code 84080) 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 step is crucial as it provides the serum or plasma needed for testing. The blood sample is then processed in a laboratory setting. The laboratory technician will utilize quantitative enzymatic methodologies to analyze the sample. This process involves heat inactivation of the sample to differentiate between the various isoenzymes of alkaline phosphatase. The isoenzymes are classified into three main types: ALPI, which is found in the intestine; ALPL, which is non-specific and present in the liver, bone, and kidney; and ALPP, which is the placental isoenzyme. By measuring the levels of these isoenzymes, healthcare providers can gain insights into the patient's health status and identify any underlying conditions that may be affecting alkaline phosphatase levels.

3. Post-Procedure

After the alkaline phosphatase isoenzyme test (CPT® Code 84080) is completed, the patient may experience minimal discomfort at the venipuncture site, which typically resolves quickly. There are no specific post-procedure care instructions required for this test, but patients are generally advised to maintain hydration and can resume normal activities immediately. The results of the test will be analyzed by a healthcare professional, who will interpret the findings in the context of the patient's overall health and any symptoms they may be experiencing. Follow-up appointments may be necessary to discuss the results and any further diagnostic or therapeutic steps that may be indicated based on the findings.

Short Descr ASSAY ALKALINE PHOSPHATASES
Medium Descr ASSAY OF PHOSPHATASE ALKALINE ISOENZYMES
Long Descr Phosphatase, alkaline; isoenzymes
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
90 Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
91 Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient.
77 Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
26 Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
95 Synchronous telemedicine service rendered via a real-time interactive audio and video telecommunications system: synchronous telemedicine service is defined as a real-time interaction between a physician or other qualified health care professional and a patient who is located at a distant site from the physician or other qualified health care professional. the totality of the communication of information exchanged between the physician or other qualified health care professional and the patient during the course of the synchronous telemedicine service must be of an amount and nature that would be sufficient to meet the key components and/or requirements of the same service when rendered via a face-to-face interaction. modifier 95 may only be appended to the services listed in appendix p. appendix p is the list of cpt codes for services that are typically performed face-to-face, but may be rendered via a real-time (synchronous) interactive audio and video telecommunications system.
GA Waiver of liability statement issued as required by payer policy, individual case
GW Service not related to the hospice patient's terminal condition
GY Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
GZ Item or service expected to be denied as not reasonable and necessary
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
Date
Action
Notes
2013-01-01 Changed Medium Descriptor changed.
Pre-1990 Added Code added.
Code
Description
Code
Description
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"