Bone Marrow Aspiration Procedures and CPT Coding Guide

Bone marrow aspiration is a bedside procedure in which a hollow needle draws liquid marrow from the back of the hip bone so it can be examined under the microscope and with specialized lab tests. For billing, a diagnostic aspiration alone is reported with CPT 38220, a core biopsy alone with 38221, and both done through the same session with 38222. This guide walks through how the procedure is done, why it is ordered, and how to code it cleanly.

Marrow examination sits at the center of hematology and oncology practice. Whether you are a patient preparing for the test or a coder reviewing a procedure note, knowing what actually happens in the room makes the paperwork far easier to get right.

What Bone Marrow Aspiration Is and Why It Is Done

Marrow is the soft tissue inside larger bones where blood cells are made. If you want the background on how it works, see our overview of the composition and function of bone marrow. An aspirate is the liquid portion, which shows individual cells in detail, while a trephine biopsy is a small solid core that shows the marrow’s architecture and overall cellularity.

The procedure is most often used to diagnose or monitor hematological conditions such as leukemias, lymphomas, myeloma, and some anemias. By analyzing the bone marrow sample, physicians can judge how well blood cells are being produced and spot abnormalities in their size, shape, or number.

Common Indications

• Unexplained cytopenias: low red cells, white cells, or platelets without an obvious cause.
• Suspected bone marrow disorders such as aplastic anemia or myelodysplastic syndromes.
• Diagnosis, staging, and response assessment in leukemia, lymphoma, and myeloma.
• Persistent abnormal blood counts or cells on a blood smear that cannot be explained.
• Fever of unknown origin, when infection or infiltration of the marrow is suspected.
• Assessment of iron stores when blood tests are inconclusive.

Symptoms that raise concern for bone marrow issues include ongoing fatigue, frequent infections, easy bruising, bleeding gums, and unintended weight loss. On examination, pallor, an enlarged liver or spleen, or tiny pinpoint bleeds called petechiae may point toward a marrow examination.

How the Bone Marrow Aspiration Procedure Is Performed

The bone marrow aspiration procedure usually takes 15 to 30 minutes from start to finish, and the needle part is only a few minutes. In my practice, most patients are surprised by how quickly it is over.

1. Consent and preparation. The clinician explains the reasons, risks, and alternatives, and checks blood thinners and platelet count.
2. Positioning. The patient lies on their side or front. The usual site is the posterior iliac crest, the bony ridge at the back of the hip.
3. Local anesthesia. The skin and the surface of the bone are numbed. Some centers also offer light sedation.
4. Aspiration. A hollow needle enters the marrow cavity, and a syringe draws a small amount of liquid marrow. This produces a brief, deep pulling sensation.
5. Biopsy, if ordered. A slightly larger trephine needle removes a thin core of bone and marrow, often through the same skin puncture.
6. Dressing and recovery. Pressure is applied, a bandage placed, and the patient rests briefly before going home.

For a step-by-step look from the patient’s side, our article on how a bone marrow biopsy is performed covers what to expect.

Risks and Safety

The procedure is generally safe. The main risks are bleeding, bruising, infection, and soreness at the puncture site, which usually settles within a few days. Careful aseptic technique and correcting severe clotting problems beforehand keep complications uncommon.

Bone Marrow Aspiration CPT Codes at a Glance

Accurate coding depends on documenting exactly what was obtained. For a deeper dive on the procedural side, see our dedicated guide to bone marrow aspiration CPT coding. The core codes are summarized below.

Practical Coding Tips

• Do not report 38220 and 38221 together for the same site and session. When both are done, 38222 is the correct single code.
• Bilateral procedures are reported according to payer policy, usually with a bilateral or laterality modifier. Check the specific payer’s rules before submitting.
• Diagnostic versus harvest: 38220 to 38222 describe diagnostic sampling. Collection of marrow for transplant uses the separate harvest codes.
• Imaging guidance, when used, may be separately reportable depending on the payer and documentation.
• Link diagnosis codes that explain medical necessity, such as the cytopenia, suspected malignancy, or staging indication.

The procedure note should state the site, side, number of passes, whether an aspirate, a core, or both were obtained, and any imaging used. Vague notes are the most common reason for coding queries and denials.

What Happens to the Sample in the Lab

Once collected, the marrow is split across several tests. Each answers a different question, and together they guide diagnosis and treatment.

• Morphology: stained smears are examined under the microscope to count and classify cells.
• Flow cytometry: identifies cell surface markers to classify leukemias and lymphomas.
• Cytogenetics and FISH: detect chromosomal changes that affect diagnosis and prognosis.
• Molecular testing: next-generation sequencing and PCR identify gene mutations that can guide targeted therapy.
• Iron stain: shows iron stores and abnormal ring sideroblasts.

Each of these lab services carries its own separate codes, billed by the laboratory or pathology service rather than the proceduralist.

From Results to Treatment

After diagnosis, management depends on the condition found. Blood cancers may call for chemotherapy, targeted drugs, immunotherapy, or a stem cell transplant. Nutritional anemias may need only supplementation and follow-up blood counts.

Repeat aspirations are common in leukemia and myeloma to check response or measure minimal residual disease, the small number of cancer cells that can remain after treatment. Each repeat procedure is coded on its own date of service.

Key Takeaways

• Bone marrow aspiration samples liquid marrow, usually from the posterior iliac crest, under local anesthesia.
• Use 38220 for aspiration alone, 38221 for biopsy alone, and 38222 when both are performed together.
• Harvest for transplant uses different codes from diagnostic sampling.
• Clear documentation of site, side, and specimens obtained prevents most coding problems.
• The procedure is generally safe; bleeding, infection, and short-lived soreness are the main risks.

Frequently Asked Questions

Does a bone marrow aspiration hurt?

The numbing injection stings briefly, and most people feel pressure rather than sharp pain. The moment of aspiration causes a short, deep pulling ache that lasts a few seconds. Soreness at the site for a few days is common and usually eased by simple pain relievers.

What is the difference between CPT 38220 and 38222?

CPT 38220 covers a diagnostic aspiration only. CPT 38222 covers a diagnostic biopsy and aspiration performed in the same session. If both samples were taken, report 38222 rather than combining 38220 with 38221.

How long do bone marrow results take?

Initial smear findings may be available within a day or two. Flow cytometry often follows within a few days, while cytogenetic and molecular results can take one to several weeks.

Can I drive home after the procedure?

If only local anesthesia was used, many people can drive home. If you received sedation, you will need someone to take you home. Your care team will give instructions based on how you feel afterward.

Is bone marrow aspiration the same as a bone marrow biopsy?

They are related but different. Aspiration draws liquid marrow to study individual cells, while biopsy removes a solid core to show the marrow’s structure. They are often done together, which is why a combined CPT code exists.