You can learn a lot about the quality and accuracy of your accounting practices from a single audit of your coding and billing records. Here are 10 common but easily preventable mistakes I uncovered in a recent audit of a multi-specialty freestanding ASC. The common denominator in each case? The facility failed to match the operative reports to the correct codes and/or modifiers. The results? The use of inappropriate procedural codes, undercoding and overcoding.

The facility treated a managed care patient for bilateral capsulotomy with removal of tissue expanders with insertion of mammary implants. These procedures were inappropriately coded as 19342 ("delayed insertion of breast prosthesis"). Instead of 19342, this case should have been coded 11970 x 2 ("replacement of tissue expander with permanent prosthesis"). The rationale can be found in the operative report, which states, "left side: the expander was removed [and] mammary implant inserted. Right side: the expander was removed [and] implant inserted." The coding and billing of 11970 twice correctly classifies the procedures.

The coder inappropriately assigned code 27397 ("hamstring tendon transplant"). However, a check of the 2002 edition of the American Academy of Orthopaedic Surgeon's Complete Global Service Data for Orthopaedic Surgery reveals that code 29888, not 27397, is the one to use for the "harvesting and insertion of fascial, tendon or bone graft." The facility was not entitled to the reimbursement for code 27397.

In addition, the coder made the mistake of inappropriately using arthroscopic meniscal repair code 29882 rather than 29881 for arthroscopic meniscectomy. The operative report states, "There was a tear in the posterior horn of the lateral meniscus. This was resected back." In other words, the claim was billed for the wrong procedure. The report actually describes a lateral meniscectomy.

A Tailor's bunionectomy procedure involves a lateral longitudinal arthrotomy, in which the fifth metatarsophalangeal (MP) joint is exposed. The lateral prominence or exostosis of the metatarsal head is resected, and the capsule is tightly imbricated. One major key to identifying the correct code as a Tailor's bunionectomy is the operative report's references to the fifth MP joint. The report states, "... the fifth metatarsophalangeal joint, where an approximate 4.5-cm linear incision was then made [and] fifth metatarsal ... exostosis was resected in toto ... An Austin-type osteotomy was then performed."

The facility undercoded the claim by only reporting CPT 26356 once. The official description for code 26356 classifies "each tendon." Thus, the facility merely had to add two 26356 code assignments to be paid for the suture repair of three flexor tendons, rather than one.

Additionally, the ASC did not submit a code for reimbursement of the operative report documentation indicating "the radial digital artery was repaired also." The use of CPT code 35207 ("repair blood vessel, direct, hand, finger") would have brought further reimbursement.

Finally, the coder erroneously assigned neuroplasty code 64702, rather than CPT 64831 ("suture of digital nerve, hand or foot; one nerve"). Again, the reason lies in the operative report: "At this point, the operating microscope was brought in and using 9-0 nylon, the radial digital nerve was repaired."

Be sure to follow up
Coding and billing audits help ensure compliance with established guidelines for validating modifiers, ICD-9-CM, CPT and HCPCS Level II code assignments. But you'll need to perform follow-up audits to assess whether your coders are staying current with changes.