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Official Description

Parathormone (parathyroid hormone)

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 83970 refers to the measurement of parathormone, also known as parathyroid hormone (PTH), which is a critical hormone produced by the chief cells in the parathyroid glands. This test is essential for assessing the levels of PTH in the blood or tissue, providing valuable insights into various metabolic processes in the body. Parathyroid hormone plays a significant role in regulating blood calcium levels, influencing the absorption and excretion of phosphate by the kidneys, and facilitating the synthesis of vitamin D. Abnormal levels of PTH can indicate underlying health issues; for instance, elevated levels may suggest hyperparathyroidism, which can be caused by parathyroid gland tumors or chronic renal failure. Conversely, decreased levels of PTH may indicate hypoparathyroidism, which can result from inadvertent removal of the parathyroid glands during thyroid surgery, autoimmune disorders, or genetic inborn errors of metabolism. The procedure for obtaining a blood sample involves a separately reportable venipuncture, while parathyroid gland tissue can be obtained through a separately reportable fine needle aspirate. The analysis of serum, plasma, or tissue samples is conducted using quantitative electrochemiluminescent immunoassay techniques, and plasma is specifically tested for parathyroid hormone using an immunoradiometric assay.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The parathormone (parathyroid hormone) test, represented by CPT® Code 83970, is indicated for various clinical scenarios where assessment of parathyroid hormone levels is necessary. The following conditions may warrant this test:

  • Hyperparathyroidism Elevated levels of parathormone may indicate hyperparathyroidism, which can be caused by parathyroid gland tumors or chronic renal failure.
  • Hypoparathyroidism Decreased levels of parathormone may suggest hypoparathyroidism, which can result from inadvertent removal of the parathyroid glands during thyroid surgery, autoimmune disorders, or genetic inborn errors of metabolism.
  • Calcium Imbalance The test may be performed in cases of abnormal blood calcium levels to help determine the underlying cause.
  • Bone Disorders It may also be indicated in the evaluation of certain bone disorders where parathyroid hormone levels could influence treatment decisions.

2. Procedure

The procedure for measuring parathormone levels involves several key steps, which are outlined as follows:

  • Step 1: Sample Collection A blood sample is obtained through a procedure known as venipuncture, which is separately reportable. This involves inserting a needle into a vein to collect the necessary blood for analysis.
  • Step 2: Tissue Sample Collection If a tissue sample is required, a fine needle aspirate is performed to obtain parathyroid gland tissue. This procedure is also separately reportable and involves using a thin needle to extract a small amount of tissue for testing.
  • Step 3: Laboratory Analysis The collected serum, plasma, or tissue samples are then subjected to testing using quantitative electrochemiluminescent immunoassay techniques. This method allows for precise measurement of parathormone levels in the samples.
  • Step 4: Specific Testing for CAP Additionally, plasma is tested for cyclase activating parathyroid hormone (CAP) using an immunoradiometric assay, which is a specific method for quantifying this hormone in the plasma.

3. Post-Procedure

After the procedure, patients may experience minimal discomfort at the venipuncture or aspirate site, which is typically transient. There are no specific post-procedure care instructions mentioned for the parathormone test; however, it is advisable for patients to monitor the site for any unusual symptoms such as excessive bleeding or signs of infection. The results of the parathormone test will be interpreted by the healthcare provider in conjunction with other clinical findings and laboratory results to determine the appropriate course of action or treatment if necessary.

Short Descr ASSAY OF PARATHORMONE
Medium Descr ASSAY OF PARATHORMONE
Long Descr Parathormone (parathyroid hormone)
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 2
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.
Q4 Service for ordering/referring physician qualifies as a service exemption
GA Waiver of liability statement issued as required by payer policy, individual case
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.
GW Service not related to the hospice patient's terminal condition
GZ Item or service expected to be denied as not reasonable and necessary
X5 Diagnostic services requested by another clinician: for reporting services by a clinician who furnishes care to the patient only as requested by another clinician or subsequent and related services requested by another clinician; this modifier is reported for patient relationships that may not be adequately captured by the above alternative categories; reporting clinician service examples include but are not limited to, the radiologist's interpretation of an imaging study requested by another clinician
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.
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.
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
AY Item or service furnished to an esrd patient that is not for the treatment of esrd
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
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.
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.
93 Synchronous telemedicine service rendered via telephone or other real-time interactive audio-only 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 away 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 is sufficient to meet the key components and/or requirements of the same service when rendered via a face-to-face interaction.
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.
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
CR Catastrophe/disaster related
GC This service has been performed in part by a resident under the direction of a teaching physician
GT Via interactive audio and video telecommunication systems
KX Requirements specified in the medical policy have been met
PD Diagnostic or related non diagnostic item or service provided in a wholly owned or operated entity to a patient who is admitted as an inpatient within 3 days
PN Non-excepted service provided at an off-campus, outpatient, provider-based department of a hospital
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
Q6 Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
QJ Services/items provided to a prisoner or patient in state or local custody, however the state or local government, as applicable, meets the requirements in 42 cfr 411.4 (b)
XE Separate encounter, a service that is distinct because it occurred during a separate encounter
XP Separate practitioner, a service that is distinct because it was performed by a different practitioner
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
Date
Action
Notes
2013-01-01 Changed Medium Descriptor changed.
Pre-1990 Added Code added.
Code
Description
Code
Description
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