Understanding coding errors helps physicians avoid pitfalls

Payers will differ with regard to standards of correct coding. However, the principles outlined here generally will be followed by most payers.

Among the major categories of coding errors:

Assume an ophthalmologist performs repair of a retinal detachment including scleral buckling, vitrectomy, and peeling of an epiretinal membrane. Correct coding would be the comprehensive code CPT 67113, repair of complex retinal detachment, with vitrectomy and membrane peeling, may include . . . scleral buckling and/or removal of lens.

An example of downcoding to use an additional code would be reporting of CPT 67108, repair of retinal detachment, scleral buckling; plus CPT 67041, vitrectomy, mechanical, pars plana approach, with removal of preretinal cellular membrane (e.g., macular pucker).

The combination of CPT 67108 with 67041 is bundled in Medicare's NCCI, but not necessarily by private payers. Reporting of both services to a payer that accepts the combination would likely result in a higher total payment than would the payment for CPT 67113 alone.

The concept of medical necessity can be nebulous. This is Medicare's definition of medical necessity, which serves as a model for many payers:

"Medical necessity is defined as the need for an item(s) or service(s) to be reasonable and necessary for the diagnosis or treatment of disease, injury or defect. The need for the item or service must be clearly documented in the patient's medical record. Medically necessary services or items are: appropriate for the symptoms and diagnosis or treatment of the patient's condition, illness, disease or injury; and provided for the diagnosis or the direct care of the patient's condition, illness, disease or injury; and in accordance with current standards of good medical practice; and not primarily for the convenience of the patient."

Absent code linking is a stumbling block regarding medical necessity. An appropriate diagnosis is required to justify a particular procedure code.

Consider the reporting of a diagnosis of anterior membrane corneal dystrophy (ICD-9 diagnosis 371.52) in a patient undergoing CPT 65756, endothelial keratoplasty. The patient may be undergoing the procedure because of pseudophakic bullous keratopathy, but the coder may note the incidental diagnosis of anterior membrane corneal dystrophy in the patient's record and apply ICD-9 code 371.52 to the claim.

This is essentially an administrative error, but will nonetheless likely result in a documented coding error.

Services that exceed the patient's medical need are also generally not medically necessary. For example, submission of CPT 92083, visual field examination, unilateral or bilateral, with interpretation and report; extended examination, every 3 to 4 months in a patient whose glaucoma is stable would exceed almost all guidelines for medical necessity. The reporter would have committed an overcoding error.

Providers that are aware of these categories are far more likely to steer clear of trouble. A program of frequent reviews of the coding patterns of all providers in your practice is strongly advised.

L. Neal Freeman, MD, MBA, is president and founder of CPR Analysts, Melbourne, FL ( http://www.cpranalysts.com/). He advises physicians nationally on coding, reimbursement, and practice management. Dr. Freeman is a practicing ophthalmic plastic surgeon and a certified specialist in physician coding. Readers may contact Dr. Freeman at nfreeman@cpranalysts.com
or 321/253-2166. CPT codes, descriptions, and other data only are copyright 2010 American Medical Association (AMA). All Rights Reserved (or such other date of publication of CPT). CPT is a trademark of the AMA. Although all efforts have been made to provide accurate information, readers should check with their specific payers for their policies and rules.