Bone marrow aspirate concentrate (BMAC) is one way clinics obtain cells for a stem cell injection. Bone marrow is taken from your body and processed the same day to concentrate the cells. Rather than being a separate treatment, BMAC is one of several cell sources, alongside fat (adipose) tissue and donated umbilical cord products.
In the US, a BMAC injection typically costs $5,000 to $13,000. No BMAC product is FDA approved for joint treatment, and clinical trial evidence for orthopedic use remains mixed.
For more context, see our broader guide to mesenchymal stem cells, the cell type BMAC is valued for containing.
What BMAC is
BMAC is a concentrated solution of cells and proteins extracted from your own bone marrow, according to Cleveland Clinic. The spinning process used to prepare it removes red blood cells and other unwanted material, leaving a sample roughly six times more concentrated in mesenchymal stem cells, platelets, and growth factors than the raw marrow draw.
It is easy to confuse BMAC with “stem cell therapy” as a whole. BMAC describes a cell source and preparation method. A clinic that injects BMAC into a knee is doing the same broad category of procedure as one that injects fat-derived or cord-derived cells. The difference is where the cells came from and how much processing they went through. It is also a different procedure entirely from a bone marrow transplant, which uses a different cell type for a different purpose.
How the procedure works
A BMAC procedure happens in three steps over roughly two hours as an outpatient visit, per Cleveland Clinic’s patient guide:
- Harvest. A provider numbs the area, then inserts a hollow needle through the lower back into the pelvic bone to draw bone marrow.
- Processing. The sample spins in a centrifuge for about 30 minutes to concentrate the cells, platelets, and growth factors and strip out material the clinic doesn’t want to inject.
- Injection. The concentrate is injected into the target joint or tissue, usually under ultrasound or fluoroscopy guidance.
Because the cells are yours and are only lightly processed before going back into your body on the same day, BMAC is often marketed as a “same-day” or “in-office” stem cell procedure, distinct from lab-cultured or donor-cell products. Our stem cell injections guide covers soreness and what clinics ask you to avoid afterward.
What BMAC costs
A BMAC injection typically runs $5,000 to $13,000 per treatment in the US, based on figures reported by US orthopedic and regenerative-medicine clinics. The exact number depends on how many joints are treated, the clinic’s location, and whether imaging guidance and follow-up visits are bundled into the price.
That range sits above the standalone PRP injection cost (often $500 to $2,000 per joint) and can run higher than a general stem cell injection cost of $3,000 to $8,000, since a BMAC procedure adds a same-day marrow harvest and centrifuge processing on top of the injection itself. See our PRP vs. stem cell therapy guide for how BMAC’s cost and evidence compare to a standalone PRP shot in more depth.
No product used in a BMAC procedure is FDA approved for joint or arthritis treatment, so there is no standard, regulated price. Every clinic sets its own. As with any self-pay treatment in this space, get an itemized quote before you commit and ask specifically whether the price covers one injection or a recommended course of more than one.
Does insurance cover it?
No major insurer, Medicare, or Medicaid plan covers BMAC for orthopedic use. All classify it as experimental or investigational, the same status they apply to other joint stem cell injections. Some clinics accept HSA or FSA funds toward the cost. Our Medicare coverage guide and insurance coverage guide cover why regenerative treatments fall outside standard coverage.
Aetna’s written policy on bone marrow aspirate is quoted in our guide to whether Aetna covers stem cell therapy, and our guide to how much Regenexx costs explains how Regenexx quotes its same-day bone marrow procedure.
What the evidence shows
The evidence on BMAC for joint pain, mostly studied in knee osteoarthritis, is a mixed and unsettled picture rather than a clear yes or no.
Two of the more rigorous published trials illustrate the split. A 2022 double-blind randomized trial in the journal Knee Surgery, Sports Traumatology, Arthroscopy injected BMAC into one knee and a hyaluronic acid shot into the other knee of the same patients, then followed them for two years. Pain scores held up better in the BMAC-treated knee at 12 and 24 months, while the hyaluronic acid knee’s improvement faded by 24 months. Even so, the study authors concluded that BMAC “did not demonstrate a clinically significant superiority” over hyaluronic acid in the short term.
A placebo-controlled trial in the American Journal of Sports Medicine went further. Researchers injected BMAC into one knee and a saline placebo into the other knee of the same 25 patients, all of whom had pain in both knees. At one week, three months, and six months, both the BMAC knee and the saline knee showed similar pain reduction, with no clear advantage for BMAC.
A broader Cochrane review of stem cell injections, including bone-marrow-derived products, for knee osteoarthritis rated the overall evidence low-certainty. A 2025 narrative review in the journal Medicina points to a likely reason for the mixed results: BMAC preparation methods, cell counts, and injection protocols vary widely from clinic to clinic and study to study, which makes it hard to compare results or know which version of “BMAC” a given trial actually tested. Most published follow-up runs 12 to 24 months; data beyond five years is scarce.
Safety profile
BMAC carries a comparatively low immune-related risk because the cells are your own, drawn and re-injected the same day. Reported side effects are mostly short-term: pain and swelling at the marrow-draw site and the injection site, occasional inflammatory flare-ups, and, less commonly, bleeding, infection, or nerve or blood vessel injury from the needle placement. A systematic review of randomized trials found overall complication rates were similar between BMAC and comparison injections, with no serious adverse events specifically tied to BMAC reported across the included studies.
One theoretical concern raised in the research literature: repeated bone marrow aspirations over time could reduce the marrow’s own stem cell reserves. This has not been well studied in real patients receiving repeated BMAC treatments, so treat it as an open question rather than a settled risk.
FDA and legal status
No BMAC product is FDA approved to treat arthritis, joint pain, or any orthopedic condition. Some of the devices clinics use to harvest and process bone marrow have been cleared by the FDA as harvesting equipment. That clearance covers the device itself. It is not a claim that the resulting injection treats your condition.
Regulators generally allow same-day, minimally processed procedures like BMAC to proceed without full premarket review under a narrow exemption (21 CFR Part 1271) for products that are “minimally manipulated” and put to “homologous use,” meaning the cells are used for essentially the same function they perform naturally in the body. Bone marrow’s natural role is making blood and immune cells. Rebuilding cartilage is a different function, so injecting BMAC into a joint for arthritis sits in a regulatory gray zone rather than a clearly exempt one. The FDA has warned that some products marketed under this “same-day procedure” framing do not meet the exemption’s requirements. Our FDA status guide walks through this exemption and how to check a specific clinic’s claim.
The bottom line on BMAC
BMAC is a bone-marrow-derived, same-day method of sourcing cells for a stem cell injection. No BMAC product carries FDA approval as a therapy. It typically costs $5,000 to $13,000 out of pocket, and it sits in a regulatory gray zone rather than a clearly exempt one. The trial evidence for orthopedic use is genuinely mixed: one trial found BMAC held its pain-relief edge over a hyaluronic acid injection at 24 months, another found no advantage over a saline placebo at six months. Ask any clinic offering BMAC for the exact preparation method, the published evidence for your specific condition, and a full itemized quote before you commit. For a joint-specific estimate, try the cost estimator.
Frequently asked questions
What is BMAC (bone marrow aspirate concentrate)?
BMAC is a concentrated solution of cells, platelets, and growth factors drawn from your own bone marrow and spun down to about six times the concentration of the original sample. It is one specific way to source cells for a stem cell injection, alongside fat (adipose) and donated umbilical cord tissue.
How much does a BMAC injection cost?
A BMAC injection typically costs $5,000 to $13,000 in the US per treatment, depending on how many joints are treated and whether the clinic bundles imaging and follow-up into the price. It usually runs higher than a standalone PRP injection but can fall in a similar range to other stem cell injections, since the harvest and lab processing add cost.
Does insurance or Medicare cover BMAC?
No. Insurers, Medicare, and Medicaid classify BMAC for orthopedic use as experimental or investigational, so it is not covered. You pay out of pocket, though some clinics accept HSA or FSA funds. See our Medicare coverage guide for the full picture.
Is BMAC FDA approved?
No BMAC product is FDA approved for joint, back, or arthritis use. The harvesting and processing devices some clinics use have been cleared by the FDA for handling tissue, but device clearance is not the same as approving BMAC as a treatment. The FDA generally treats minimally processed, same-day BMAC as exempt from premarket review only when it meets a strict 'minimal manipulation' and 'homologous use' test, and injecting bone marrow cells into a joint to treat arthritis often falls outside that test. Our FDA status guide explains the exemption in more detail.
Does BMAC work better than PRP or other stem cell injections?
The evidence is mixed and does not show a clear winner. Some trials found BMAC outperformed hyaluronic acid injections for knee osteoarthritis pain, while a placebo-controlled trial found no significant difference between BMAC and a saline injection. No large trial has proven BMAC beats PRP or fat-derived cells for joint pain.
What are the risks of a BMAC injection?
Reported risks include pain and swelling at the marrow-draw and injection sites, inflammatory reactions, bleeding, infection, and nerve or blood vessel injury, most of them temporary. Because BMAC uses your own cells, rejection risk is low. Repeated bone marrow draws over time are a theoretical concern for depleting your marrow's stem cell reserves, though this is not well studied in patients.
Medical disclaimer. Medical Frontier is an independent educational resource. This page is for general information only and is not medical advice, diagnosis, or treatment, and does not create a doctor–patient relationship. Most regenerative therapies discussed here are not FDA-approved for the uses described and may be offered under limited exemptions or in clinical trials only. Always consult a licensed physician before making any treatment decision.