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Official Description

Estradiol; free, direct measurement (eg, equilibrium dialysis)

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 82681 refers to a laboratory test that measures the concentration of free estradiol in the blood through a direct measurement method, such as equilibrium dialysis. Estradiol is a key hormone in the estrogen family, predominantly produced by the ovaries in non-pregnant women, and is crucial for various physiological functions. This test is particularly significant for evaluating ovarian function, diagnosing conditions such as precocious puberty, amenorrhea, and gynecomastia in males. Additionally, it plays a vital role in monitoring follicle development during in-vitro fertilization procedures and assessing hormone replacement therapy effectiveness in post-menopausal women. Estradiol levels fluctuate throughout the menstrual cycle, with normal ranges for menstruating women being between 15-350 picograms per milliliter (pg/mL), while postmenopausal women typically exhibit levels below 10 pg/mL. The measurement of free estradiol is essential as it reflects the bioactive fraction of the hormone, providing a more accurate assessment of its physiological effects. The testing process involves a meticulous procedure where serum samples undergo a 22-hour dialysis, followed by liquid-liquid extraction and derivatization, ultimately utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS) for precise measurement.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The measurement of free estradiol is indicated for various clinical scenarios, particularly in evaluating hormonal levels and reproductive health. The following conditions warrant this laboratory test:

  • Ovarian Function Evaluation This test is performed to assess the functionality of the ovaries, which is crucial for understanding reproductive health.
  • Precocious Puberty Diagnosis Free estradiol levels are measured to help diagnose precocious puberty in children, a condition characterized by the early onset of secondary sexual characteristics.
  • Amenorrhea Assessment The test aids in diagnosing the underlying causes of amenorrhea, which is the absence of menstruation in women of reproductive age.
  • Gynecomastia in Men In males, estradiol levels are evaluated to determine the cause of gynecomastia, which is the enlargement of breast tissue.
  • Monitoring Follicle Development For women undergoing in-vitro fertilization, this test is essential for monitoring the development of ovarian follicles.
  • Hormone Replacement Therapy Monitoring In post-menopausal women, free estradiol levels are measured to assess the effectiveness of hormone replacement therapy.

2. Procedure

The procedure for measuring free estradiol involves several critical steps to ensure accurate results. The process begins with the collection of serum samples from the patient. Following collection, the serum samples undergo a dialysis process lasting 22 hours, known as equilibrium dialysis. This step is crucial as it separates the free estradiol from the bound fraction, allowing for a more accurate measurement of the bioactive hormone. After dialysis, the samples are subjected to liquid-liquid extraction using an organic solvent, typically ether, to isolate the estradiol from other serum components. Subsequently, the extracted estradiol undergoes derivatization with dansyl chloride, a chemical reaction that enhances the detection of the hormone. Finally, the concentration of free estradiol is quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a highly sensitive and specific analytical technique that provides precise measurements of hormone levels in the serum.

3. Post-Procedure

After the procedure, there are generally no specific post-procedure care requirements for patients, as the test is minimally invasive and involves only blood sample collection. Patients may resume normal activities immediately following the blood draw. However, it is essential for healthcare providers to communicate the expected timeline for receiving results, which may vary depending on the laboratory's processing time. Additionally, clinicians should discuss the interpretation of results with patients, particularly in the context of their specific health conditions and treatment plans.

Short Descr ASSAY DIR MEAS FR ESTRADIOL
Medium Descr ASSAY OF DIRECT MEASUREMENT FREE ESTRADIOL
Long Descr Estradiol; free, direct measurement (eg, equilibrium dialysis)
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) none
MUE 1
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.
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
Date
Action
Notes
2021-01-01 Added Code added.
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