The CPT codes you need for bone marrow procedures are 38222 (biopsy), 38220 (aspiration), and 38221 (aspiration for smear only). When both a biopsy and aspiration are performed at the same session — which they are roughly 90% of the time — you report 38222 as the primary code and 38220 with modifier 59 to indicate a distinct procedural service. Getting this right is the difference between clean reimbursement and a stack of denials.
These codes were restructured by the AMA in 2018, and the changes still trip up coders and billing departments. The old code 38220 used to cover both aspiration and biopsy together. Now the codes are unbundled, which gives more specificity but also creates more opportunities for errors. Let’s break down exactly how each code works, when to use them, and how to avoid the most common billing mistakes.
Bone Marrow Biopsy and Aspiration CPT Code Breakdown
| CPT Code | Description | Procedure | 2024 National Average Reimbursement (Medicare) |
|---|---|---|---|
| 38220 | Bone marrow aspiration (diagnostic) | Needle inserted to withdraw liquid marrow for cytology, flow cytometry, or cultures | ~$126 |
| 38221 | Bone marrow aspiration for smear only | Simple aspiration yielding material only sufficient for a smear — no additional studies | ~$80 |
| 38222 | Bone marrow biopsy (trephine) | Core needle biopsy obtaining a solid cylinder of bone and marrow tissue | ~$198 |
When Both Aspiration and Biopsy Are Done Together
In most clinical scenarios — staging lymphoma, evaluating unexplained cytopenias, diagnosing leukemia — the hematologist performs both an aspiration and a trephine biopsy at the same sitting. This is standard practice because aspiration gives you cell morphology and flow cytometry data, while the core biopsy reveals marrow architecture, cellularity, and fibrosis.
For billing purposes, report 38222 + 38220-59. The modifier 59 tells the payer these are distinct procedures, not duplicate billing. Some payers accept modifier XS (separate structure) as a replacement for 59 under the newer X{EPSU} modifier system. Check your payer’s specific policy.
Do not report 38221 with 38220. Code 38221 is a subset of 38220. If you obtain enough aspirate for flow cytometry, cytogenetics, or molecular studies — not just a smear — use 38220. Code 38221 exists for the uncommon situation where aspiration yields only enough material for a simple morphologic smear.
Common Billing Mistakes and Denial Triggers
- Forgetting modifier 59 on 38220 when billed with 38222. Without it, CCI edits will bundle the aspiration into the biopsy and you’ll only get paid for one procedure.
- Billing 38221 + 38220 together. These are mutually exclusive. The aspirate either met criteria for full diagnostic studies (38220) or it didn’t (38221). It can’t be both.
- Reporting bilateral procedures without documentation. If bone marrow is sampled from both iliac crests (uncommon but done in some staging protocols), append modifier 50 to indicate bilateral. Document the medical necessity thoroughly.
- Missing the pathology codes. The biopsy/aspiration CPT codes cover the procedure only. Pathologic interpretation is reported separately under 88305 (surgical pathology) for the core biopsy and 85097 for the bone marrow smear interpretation.
- Using the wrong ICD-10 codes. A diagnosis of “abnormal CBC” (R79.89) or “cytopenia” (D70-D72 series) supports medical necessity. Vague codes like R68.89 (“other general symptoms”) can trigger medical necessity denials.
Key ICD-10 Codes Commonly Paired with Bone Marrow Procedures
| ICD-10 Code | Description |
|---|---|
| D46.9 | Myelodysplastic syndrome, unspecified |
| C91.00 | Acute lymphoblastic leukemia, not in remission |
| C90.00 | Multiple myeloma, not in remission |
| D61.9 | Aplastic anemia, unspecified |
| D75.9 | Disease of blood and blood-forming organs, unspecified |
| D69.6 | Thrombocytopenia, unspecified |
| R79.89 | Other specified abnormal findings of blood chemistry |
Facility vs. Professional Billing
If the procedure is performed in a hospital outpatient setting, the facility reports the procedure under the Outpatient Prospective Payment System (OPPS) using the same CPT codes, and the physician bills separately for the professional component. In an office-based setting, the physician captures both the technical and professional components in a single global claim.
Reimbursement is generally higher in the office setting because the overhead is bundled into the payment. For 38222, the office-based global payment can be approximately 30-40% higher than the professional-only fee in a facility setting.
What About Repeat Bone Marrow Procedures?
Patients with hematologic malignancies often undergo serial bone marrow biopsies — at diagnosis, mid-treatment, post-induction, and for surveillance. Each procedure is coded independently. There’s no limit on how many times you can bill these codes, but each occurrence needs its own documented medical necessity. A note saying “routine follow-up” isn’t sufficient; specify what clinical question the repeat biopsy is answering.
Frequently Asked Questions
Can 38220 and 38222 be billed together?
Yes — this is the most common scenario. Report 38222 as the primary procedure and append modifier 59 (or XS) to 38220. Both codes must be supported by documentation showing that an aspiration and a core biopsy were separately performed and that specimens were sent for distinct analyses.
What replaced the old bone marrow biopsy CPT code 38221?
Code 38221 still exists, but its definition was narrowed in the 2018 revision. It now specifically covers aspiration for smear only. The previous code 38220 was split so that 38222 became the dedicated trephine biopsy code. If you’re still using pre-2018 coding habits, your claims are almost certainly being processed incorrectly.
Does bone marrow biopsy require prior authorization?
Most commercial payers do not require prior authorization for diagnostic bone marrow procedures when supported by appropriate ICD-10 codes indicating cytopenias, suspected malignancy, or disease monitoring. However, some Medicare Advantage plans and a handful of commercial plans do require prior auth. Always verify with the specific payer.
Who can bill for a bone marrow biopsy — only hematologists?
Any qualified physician or advanced practice provider (NP/PA) operating within their scope of practice and credentialed to perform the procedure can bill these codes. Hematologists, oncologists, pathologists, hospitalists, and even some trained internists perform bone marrow procedures. Payer credentialing — not specialty — determines billing eligibility.
How do I code a dry tap?
If aspiration yields no marrow material (a “dry tap”), you can still bill 38220 if the aspiration was attempted and documented. Append modifier 52 (reduced services) if no diagnostic material was obtained. The trephine biopsy (38222) should still be billed normally since a dry tap actually increases the diagnostic importance of the core biopsy — it often suggests marrow fibrosis or a packed marrow.
Key Takeaways
- 38222 + 38220-59 is the standard coding combination for same-session biopsy and aspiration.
- Never bill 38220 and 38221 together — they’re mutually exclusive.
- Always document medical necessity with specific ICD-10 codes; vague diagnoses invite denials.
- Pathology interpretation is billed separately (88305, 85097) — don’t leave money on the table.
- For dry taps, use modifier 52 on 38220 and still bill 38222 in full.
