77080

DEXA bone density study, axial skeleton (e.g., hip, spine, proximal femur, whole body)

Dual-energy X-ray absorptiometry (DEXA or DXA) of the axial skeleton is a non-invasive, low-radiation imaging procedure used to measure bone mineral density (BMD) at critical sites such as the lumbar spine, proximal femur (hip), and sometimes the whole body. It is considered the gold standard for the diagnosis of osteoporosis and osteopenia, and for assessing an individual's risk of fragility fractures. The procedure utilizes two distinct X-ray energies to differentiate between bone and soft tissue, allowing for precise quantification of BMD (expressed in g/cm²) and comparison to age- and sex-matched reference populations through T-scores and Z-scores. The acquired images and calculated BMD values are then interpreted by a qualified physician to guide clinical management, including treatment initiation or modification.

Clinical Indications

  • Diagnosis of osteoporosis or osteopenia
  • Monitoring the effectiveness of osteoporosis treatment
  • Assessment of fracture risk in individuals with established risk factors (e.g., postmenopausal women, men over 50 with risk factors, long-term corticosteroid therapy)
  • Evaluation of bone loss secondary to endocrine disorders (e.g., hyperparathyroidism), chronic diseases (e.g., chronic kidney disease), or malabsorption syndromes
  • History of a low-trauma or fragility fracture
  • Radiographic evidence of vertebral fracture or osteopenia detected on other imaging studies

Procedure Steps

  1. Patient identification and explanation of the procedure, including removal of metallic objects.
  2. Patient positioned supine on the DEXA scanner table.
  3. Specific anatomical positioning for each site: for lumbar spine, patient's legs may be elevated; for hip, the leg is internally rotated to optimize femoral neck projection.
  4. Acquisition of dual-energy X-ray images of the targeted axial skeleton sites.
  5. Automated software analysis of the acquired data to calculate BMD for regions of interest (e.g., L1-L4, total hip, femoral neck).
  6. Generation of images, BMD reports, T-scores (comparison to young adult reference), and Z-scores (comparison to age-matched reference).
  7. Interpretation of the study findings by a radiologist or other qualified physician and preparation of a diagnostic report.

Coding Guidelines

  • Code 77080 typically includes scanning of common axial skeleton sites such as the lumbar spine and hip(s). It is generally billed once per encounter for comprehensive axial skeleton assessment.
  • Medical necessity must be clearly documented in the patient's medical record, including relevant clinical indications, risk factors, and prior bone density results if applicable.
  • Frequency of DEXA scans is typically limited by payer policies (e.g., once every two years), but may be justified more frequently (e.g., annually) for patients on specific pharmacologic treatments or with medical conditions causing rapid bone loss.
  • For the professional component of the service, append modifier 26. For the technical component only, append modifier TC.
  • Do not bill 77080 in conjunction with CPT code 77081 (bone density study, appendicular skeleton) unless distinct clinical indications for each site are met and separate reports are generated.
  • CPT code 77089 (Vertebral Fracture Assessment - VFA) may be reported in addition to 77080 when performed concurrently, provided medical necessity for VFA is documented and it represents a separately identifiable service.

Associated ICD-10 Codes