All about Grafts for Orthopedics: Allografts vs Autografts


Friday Follow: Medical Billing and Coding CPT Drill Down
All About Grafts for Orthodpedics: Allografts VS Autografts

By Holly Cassano, CPC

It seems every October when the annual CPT/ICD-9 updates are published, orthopedics is always on the roster. Graft procedures are a component of orthopedics, and these procedures seem to cause much confusion to both providers and billers/coders when it comes to the various types and proper billing and coding of these procedures.

Spinal fusion or arthrodesis procedures are one of the primary procedures where bone grafts are utilized. Typically, bones are fused in order to promote healing into a single bone by utilizing additional bone obtained through a graft procedure. There are a variety of graft types and sometimes they are combined during a procedure, depending on the nature of the presenting problem the surgeon is repairing.

Grafts can be utilized for a number of procedures to promote healing, provide structural support, correct deformities, repair fractures, and traumatic injuries, cranial/facial reconstruction, and cancer. For spinal surgery, the use of bone grafts assist in the healing and remodeling of the spine after surgery.

How It’s Done
For autograft or allograft insertion, an incision is made in the skin over the bone defect, and the bone graft/or replacement material is molded to fit the area and is held in place with pins, plates, or screws.

Autograft Specifics
An incision is made over the ilium, fibula, or other site from which the local autograft will be harvested, down to the fascia and muscle, which are retracted, utilizing a knife/chisel/cutter/saw to retrieve the material which will be prepped for implantation in the spine. Closure is via sutures.

Grafts and More Grafts

  • Autograft: The standard technique used in fusion, involves taking extra bone from one part of the body (harvest) and moving (graft) it to another part of the body.
  • Cadaver or Allograft Bone: Many surgeons use bone that is harvested from a donor or cadaver. This type of graft is typically acquired through a bone bank.
  • Synthetic Bone: These grafts are made from calcium materials and are often called a ceramic and mimic autograft bone. They are made without use of cadaver bone.
  • Bone Marrow: Bone marrow is located in the centers of long bones, such as the bones in your arms, thighs, and legs. This is where stem cells are found, and if used, they have the capability to form new bone.
  • Biologics or Proteins: Morphogenic protein (BMP) has been used to promote solid spine fusions and is a common graft option, as it has key bone-forming abilities.

Know Graft Type for Billing and Coding
Billing and coding for bone grafts is dependent upon knowing the difference between the two. Knowing if the graft is structural or morselized, and/or an allografts or autografts is key in choosing the the accurate CPT code for billing.

Fact: Only one bone graft code from this section can be billed per case.

Tip: If both allografts and autografts are used, bill an autograft code from the graft section, not an allograft, as it is already being billed with code L8699 for purchased implants.

More Tips

  • A structural graft is a bigger piece of bone.
  • A morselized graft involves cancellous bone or small bone fragments.

CPT Codes for Autografts

  • CPT 20936 – Localized Autograft (same incision) for spine surgery only (includes harvesting the graft); local (e.g., ribs, spinous process, or laminar fragments) (List separately in addition to code for primary procedure)
  • CPT 20937 – Localized autograft (separate incision) for spine surgery only (includes harvesting the graft); morselized (List separately in addition to code for primary procedure) Billed/coded with 38220-59.

CPT Codes for Allografts

  • CPT 20930 – Morselized allograft that is purchased
  • CPT 20931 – Structural allograft that is purchased

Tip: Bill code L8699 with the implant and/or other valid code for purchased implant used in allografts

Risks and Benefits of Bone Grafts
Risks are always associated with any type of surgery, and orthopedic procedures that utilize bone grafts are no exception. The following list illustrates some of the associated risks and benefits for allografts and autografts:


  • Allograft bone may be provided by a living donor, but is generally obtained from cadaver donors.
  • Allografts eliminate patient from undergoing a second procedure to harvest bone or tendon required for an autograft
  • Allografts reduce the risk of infection and increases relief of pain and minimizes functional loss from the harvested site.

Allografts also have drawbacks:

  • Grafted bone requires a longer assimilation time into host body
  • Disease transfer risk
  • Higher rejection risk


  • Have a low risk for rejection
  • Longer OR time to allow for bone
  • Increased costs for longer OR time
  • Increased pain and/or risk of infection from harvest site
  • Increased risk of complications

Final Thoughts
Bone grafts are intricate and necessary procedures for orthopedic billing and coding. It is essential that these professionals have a solid grasp on these procedures and maintain their skills via seminars/webinars/online tools/books in order to receive accurate payment with ever-increasing cuts to physician reimbursement.

For more information on bone grafts from the American Academy of Orthopedic Surgeons, please click here.

Happy Coding!