CPT® Code 84305 is used to report laboratory testing for Somatomedin-C, also known as Insulin-like Growth Factor 1 (IGF-1). IGF-1 is a hormone primarily produced in the liver and is stimulated by growth hormone (GH). Measuring IGF-1 levels helps evaluate growth hormone activity and is commonly used in the diagnosis and management of growth hormone deficiencies, growth disorders, and conditions related to abnormal growth hormone production such as acromegaly or gigantism.
IGF-1 testing is often used instead of random growth hormone testing because IGF-1 levels remain more stable throughout the day.
Key Facts About CPT® 84305
Service type: Laboratory hormone test
Provider type: Physicians and qualified healthcare professionals who order laboratory testing
Medical services included: Yes, quantitative measurement of Somatomedin-C (IGF-1)
Specimen type: Serum
Test method: Quantitative immunoassay or equivalent laboratory method
Common clinical indications:
- Evaluation of growth hormone deficiency
- Assessment of short stature or growth delay in children
- Diagnosis of acromegaly or gigantism
- Monitoring growth hormone therapy
- Evaluation of pituitary gland disorders
When to Use CPT® 84305
CPT 84305 is appropriate when:
- IGF-1 testing is ordered to evaluate growth hormone function
- The test is medically necessary based on clinical symptoms or suspected endocrine disorder
- Results are used to diagnose or monitor growth hormone-related conditions
- The test is performed on a properly collected serum specimen
Examples:
- Evaluating a child with growth delay or short stature
- Testing for suspected acromegaly in an adult patient
- Monitoring response to growth hormone therapy
- Assessing pituitary function in patients with endocrine disorders
Documentation Requirements
To support CPT 84305 billing, documentation should include:
- Patient identifiers and date of service
- Provider order for Somatomedin-C (IGF-1) testing
- Clinical indication or medical necessity
- Specimen type and collection date
- Laboratory test results and reference ranges
- Ordering provider credentials and signature
- Laboratory performing the test
Complete documentation supports accurate billing, compliance, and clinical decision-making.
Reimbursement and Coding Considerations
- CPT 84305 is reimbursed when medically necessary and properly documented
- Coverage depends on diagnosis, endocrine-related symptoms, and payer policies
- IGF-1 testing is commonly used alongside growth hormone testing and pituitary evaluation
- Proper diagnosis coding should support endocrine or growth-related conditions
- Verify payer-specific guidelines for hormone testing reimbursement
Accurate coding and documentation help ensure appropriate reimbursement and reduce claim denials.
How OptiMantra Supports Somatomedin-C (IGF-1) Testing
OptiMantra’s integrated EMR and practice management system streamlines ordering, documentation, and billing for CPT 84305:
With OptiMantra, providers can:
- Order IGF-1 testing directly from the patient chart
- Document endocrine-related symptoms and clinical indications
- Track hormone levels and trends over time
- Link lab findings to diagnoses, treatment plans, and follow-up care
- Support compliant, audit-ready billing codes for laboratory services
By centralizing endocrine lab workflows, OptiMantra helps practices improve efficiency, ensure compliance, and optimize reimbursement.
Try OptiMantra for free here!
Disclaimer: CPT® codes are maintained by the American Medical Association. This guide is for informational purposes only and does not replace official coding guidelines or payer policies.
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