Folate (vitamin B9) is an essential nutrient that plays a critical role in DNA synthesis, red blood cell formation, and neurological function. Deficiency can lead to severe conditions such as megaloblastic anemia, neural tube defects in pregnancy, and elevated homocysteine levels, increasing cardiovascular risks.
Given its clinical significance, accurate laboratory testing and proper medical billing for folate tests are crucial. This guide explores the CPT code for folate testing, insurance considerations, billing best practices, and the latest advancements in folate diagnostics.

CPT Code for Folate
2. Understanding Folate and Its Importance
Folate, a water-soluble B vitamin, exists naturally in foods like leafy greens, legumes, and liver. Its synthetic form, folic acid, is used in supplements and fortified foods.
Key Functions of Folate:
-
Supports DNA and RNA synthesis
-
Essential for red blood cell production
-
Reduces homocysteine levels, lowering cardiovascular risk
-
Critical for fetal development during pregnancy
Deficiency can result from poor diet, malabsorption disorders (e.g., celiac disease), alcoholism, or certain medications (e.g., methotrexate).
3. Clinical Indications for Folate Testing
Doctors order folate tests when patients exhibit:
-
Megaloblastic anemia symptoms (fatigue, weakness, pallor)
-
Neurological symptoms (numbness, cognitive decline)
-
High homocysteine levels
-
Pregnancy or preconception care
-
Malabsorption disorders
4. Types of Folate Tests
A. Serum Folate Test (CPT 82746)
Measures circulating folate levels in blood plasma. Best for detecting short-term deficiency.
B. Red Blood Cell (RBC) Folate Test (CPT 82747)
Assesses long-term folate status by measuring folate stored in red blood cells. More accurate for chronic deficiency.
Table: Comparison of Serum vs. RBC Folate Testing
| Parameter | Serum Folate (CPT 82746) | RBC Folate (CPT 82747) |
|---|---|---|
| What It Measures | Circulating folate in plasma | Folate stored in RBCs |
| Best For | Short-term deficiency | Long-term deficiency |
| Stability | Fluctuates with diet | More stable over time |
| CPT Code | 82746 | 82747 |
5. CPT Codes for Folate Testing
The two primary CPT codes for folate testing are:
A. CPT 82746: Folic Acid (Folate), Serum
-
Used for serum folate testing
-
Typically reimbursed by Medicare and private insurers
B. CPT 82747: Folic Acid (Folate), RBC
-
Used for RBC folate testing
-
Often required for pregnancy and chronic deficiency cases
When to Use Each Code:
-
82746: Suspected acute deficiency, post-folic acid supplementation monitoring.
-
82747: Chronic deficiency evaluation, pregnancy, malabsorption disorders.
6. Insurance Coverage and Reimbursement
Most insurers cover folate testing if medically necessary. Documentation should include:
-
Symptoms (e.g., anemia, neurological issues)
-
Risk factors (malabsorption, pregnancy)
-
Diagnosis codes (e.g., D52.9 for folate deficiency anemia)
Medicare Coverage:
-
Covered under CLIA-approved labs
-
Requires ICD-10 codes supporting medical necessity
7. How to Properly Bill Folate Tests
To avoid claim denials:
-
Use the correct CPT code (82746 or 82747).
-
Link to a relevant ICD-10 code (e.g., D52.9, O25, E53.8).
-
Document medical necessity in patient records.
-
Verify payer-specific guidelines (some require prior authorization).
8. Common Billing Errors and Fixes
| Error | Solution |
|---|---|
| Using the wrong CPT code | Confirm if serum or RBC test was performed |
| Missing ICD-10 linkage | Always attach a supporting diagnosis |
| Lack of medical necessity documentation | Include symptoms and risk factors |
9. Folate vs. Vitamin B12 Testing
-
Folate (B9) deficiency → Treat with folic acid.
-
B12 deficiency → Requires B12 injections (if malabsorption exists).
-
Misdiagnosis risk: Low folate can mask B12 deficiency, worsening neurological damage.
10. Folate Testing in Pregnancy
-
RBC folate (CPT 82747) is preferred for assessing neural tube defect risk.
-
CDC recommends 400–800 mcg/day folic acid for pregnant women.
11. Future Trends in Folate Testing
-
Genetic testing for MTHFR mutations affecting folate metabolism.
-
At-home folate test kits (emerging but not yet standard).
12. Conclusion
Folate testing is vital for diagnosing deficiencies, managing anemia, and ensuring healthy pregnancies. Proper use of CPT 82746 (serum) and 82747 (RBC), along with accurate ICD-10 coding, ensures reimbursement. Stay updated on evolving testing methods and payer policies to optimize billing efficiency.
13. FAQs
Q1: What is the difference between CPT 82746 and 82747?
-
82746 = Serum folate (short-term levels).
-
82747 = RBC folate (long-term storage).
Q2: Does Medicare cover folate testing?
-
Yes, if medically necessary and properly documented.
Q3: Can folate and B12 tests be billed together?
-
Yes, but medical necessity must justify both tests.
Q4: What ICD-10 codes support folate testing?
-
D52.9 (Folate deficiency anemia), O25 (Pregnancy-related malnutrition).
14. Additional Resources
-
CDC Folate Guidelines: www.cdc.gov
-
AMA CPT Code Updates: www.ama-assn.org
-
Medicare Coverage Database: www.cms.gov
