Colonoscopy is the most effective diagnostic procedure for finding and treating colon polyps and for the early detection of colorectal cancer, but coding this procedure correctly can be vexing. Be sure to share these 11 guidelines with your business staff:

Qualifying as a colonoscopy. A colonoscopy is a visual examination of the lining of the large intestine with a flexible fiberoptic endoscope. The key to accurately coding these procedures depends on knowing exactly what the surgeon did and the final destination of the scope. To qualify as a colonoscopy procedure, the scope must move beyond the splenic flexure of the colon.

Adhere to payer policies. Most states' Medicare carriers publish an LMRP (Local Medical Review Policy) or LCD (Local Coverage Determination) detailing their policy for colonoscopy procedures. Points to keep in mind:

• Your best bet to avoid medical necessity denials is to follow these policies.
• Don't list on your Medicare claims any diagnosis that doesn't appear on the LMRP diagnosis coding list.
• If you can't locate a covered diagnosis in the report, look to the patient's H & P for signs and symptoms for the reason the test was performed.

Avoid canned reports. When documenting colonoscopy procedures, be sure procedure reports indicate the medical necessity of the procedure. Strongly discourage the use of canned procedure reports for colonoscopies and other procedures. Medicare frowns on the use of canned op reports (called "record cloning"), and can recoup payments if it discovers you've used such reports.

When a diagnostic procedure turns therapeutic or surgical. If the performing physician begins the colonoscopy as a diagnostic procedure, and the test turns into a therapeutic or surgical procedure through the same scope, you can only bill the surgical or therapeutic procedure.

For a diagnostic colonoscopy. Use CPT code 45378 for those patients having a colonoscopy done because they're having symptoms (such as blood in stool, constipation or abdominal pain). You wouldn't use this code for a screening colonoscopy procedure for a Medicare patient, which should be billed with the appropriate G-code. Use the 45378 code for a screening colonoscopy procedure for payers other than Medicare.

Screening colonoscopy procedures on high-risk Medicare patients. Use CPT code G0105. These are covered every 24 months. The high risk category for colon cancer means patients with a personal or family history of polyps or colon cancer.

Screening colonoscopy procedures on non-high-risk Medicare patients. Use the G0121 procedure code for a cancer screening on Medicare patients not meeting the criteria for high risk. These are covered once every 10 years. If the physician detects a lesion or growth and biopsies or removes it during the course of a screening colonoscopy, use the appropriate diagnostic or therapeutic colonoscopy code based on the method the physician used to remove the lesion. Don't use the screening study G-code in this instance.

GI biopsies. The CPT Assistant states that GI biopsies involve the "use of a forceps to grasp and remove a small piece of tissue without the application of cautery. The biopsy may be from an obvious lesion that is too large to remove from a suspicious area of abnormal mucosa, or from a lesion or polyp so small that it can be completely removed during the performance of the biopsy." If a physician biopsies a lesion and then subsequently removes the same lesion during the same operative session, code the removal of the lesion only by the method used for removal.

Biopsy and removal in the same session. For either a colonoscopy or EGD procedure, if the one lesion is biopsied, and a separate lesion is removed during the same operative session, code the biopsy of the lesion and also code the removal of the separate lesion. If you unbundle the procedures, use a ?59 modifier on the biopsy procedure. For colonoscopy procedures, by definition, a "separate site" can be a separation as small as one centimeter.

Incomplete colonoscopies. Failed colonoscopies, also referred to as "incomplete," occur when the physician can't advance the colonoscope past the splenic flexure, due to such factors as incomplete preps, unusual anatomy or an obstructing lesion. Code these procedures with the ?52 modifier. Be sure the physician documents how far he advanced the scope and the reason for the incomplete study.

Multiple lesions by multiple methods. When a physician removes two (or more) separate lesions by two different methods, you may bill the code for each method used with a ?59 modifier if the codes are unbundled. Use CPT code 45380 for the removal of portions of a polyp or the entire polyp by cold biopsy forceps. If the physician attempts - but fails - to remove a polyp by one technique, but is successful at removing the polyp via another technique, bill only the CPT code for the procedure that was successful. Only use the code for each technique used for biopsies and polypectomies once, regardless of the number of lesions removed or biopsies taken, as each code is for the removal of a single or multiple lesions.

Coding intricacies
Next to cataracts, colonoscopy is the top Medicare-reimbursed surgical procedure, accounting for 15 percent of Medicare payments to surgery centers. As you can see, you and your coders need to be aware of many coding intricacies.