Orthopedic Coding Alert

Don't Append -51 to Spinal Bone Graft Codes

According to the February 1996 CPT Assistant, "Codes 20930-20938, although appearing under the heading of General Musculoskeletal Procedures, apply only to bone grafts used for spine surgery ... These are specifically identified as add-on procedures. The -51 modifier is not used when these codes are reported with the definitive spine surgery code."

Because modifier -51 (Multiple procedures) does not apply to these grafting codes, your payer should not cut your fee when you report 20931, 20937 or 20938 with an arthrodesis code. But if you report 20930 or 20936, don't expect to collect. Medicare assigns no relative value units to these procedure codes and considers them "bundled" services, meaning that they will always be bundled into the more extensive procedure.

Is the Graft From the Patient? Use Autograft Codes

Surgeons obtain bone grafts from either an allograft or an autograft, and the codes differ depending on the material the physician uses.

If the orthopedist obtains the graft from the patient's own body (for example, he takes bone from the patient's rib to complete a spinal fusion), you should report an autograft code (20936-20938). Select 20936 if he obtains the graft from a bone he accesses through the same incision as the fusion, says Annette Grady, CPC, CPC-H, senior healthcare consultant at Eide Bailly LLP in Bismarck, N.D., and chair of the North American Spine Society's administrative task force. Choose 20937 or 20938 if the surgeon must create a separate skin or fascial incision at a different site to harvest the graft.

Surgeons do not personally harvest allografts, which explains why reimbursement is normally $60-80 less for allograft codes than autograft. Allografts are harvested from cadavers or living donors and are frozen in a bone bank until the surgeon needs to use them. Codes 20930 and 20931 refer to the surgeon's work preparing and placing the graft.

CPT further breaks down grafting codes as morselized or structural. Structural bone grafts (20931 and 20938) consist of single pieces of bone that provide direct support for skeletal structures.

Morselized grafts (20930 and 20937) consist of small bone fragments joined together to fill bony cavities, primarily to promote new bone growth. 

Don't Stop With One Grafting Code

Surgeons who perform complicated arthrodesis procedures at multiple levels might use more than one graft type, and in some situations you can collect reimbursement for each grafting procedure.

The Rules: If the surgeon uses the same type of graft multiple times, some payers will not reimburse you for additional levels. According to the January 2004 CPT Assistant, "Each type of bone graft code for spinal surgery (20930-20938) may be reported one time for a spinal procedure, regardless of the number of vertebral levels being surgically fused (i.e., not once per spinal interspace or segment fused)."

The phrase "Each type of bone graft" leaves some coders wondering how to report a session in which the surgeon uses both autograft and allograft.

Solution: Although CPT once advised coders to report only one graft code per session, CPT eliminated this instruction in 2001, Grady says. And, the NCCI does not bundle the grafting codes into one another, and some coders have reported success billing more than one grafting code when the surgeon places grafts at multiple levels. "When billing in this manner, be sure to include an operative report clearly illustrating that the surgeon addressed two separate interspaces (e.g., C5/C6 and C6/C7)," Grady says.

Some payers may not reimburse more than one grafting code per operative session, but this does not apply to every insurer, so in the absence of specific payer guidelines, you should report each separate type of graft that your surgeon performs.

"The 2003 North American Spine Society (NASS) publication, Common Coding Scenarios for Comprehensive Spine Care, advises coders to list more than one bone graft code for spine procedures if it was done," says Denise Paige, CPC, coding manager at Beach Orthopedic Associates in Long Beach, Calif., and president of the American Academy of Professional Coders' Long Beach Chapter. "Whether or not you will be paid for more than one bone graft is another issue, but for reporting purposes it would be wise to list each type of bone graft used."