Pediatric Coding Alert

Question: A 15-year-old diabetic patient came in complaining of weakness, tremors and confusion. We performed a stat glucose, which revealed hypoglycemia with a value of 40. We gave the patient glucose gel and retested him 15 minutes later. He was still hypoglycemic with a value of 55. We provided more glucose tablets and retested him 15 minutes later. His glucose was then normal, and he reported relief of his symptoms, so we sent him home. When we billed the three blood glucose tests, (82947, Glucose; quantitative, blood), only one was paid. How should we bill to get paid for all three tests? Michigan Subscriber Answer: When providers perform repetitive laboratory tests on the same day, append modifier -91 (Repeat clinical diagnostic laboratory test) to the test code. This lets the payer know that the tests you are billing are not duplicates.

The instructional notes in CPT caution that you should not use this modifier to bill for tests that must be repeated because of testing problems with specimens or equipment. Also, you should not use it for codes that by definition require serial measurements. For instance, the code for glucose tolerance tests includes a number of measurements the physician must perform over a three-hour period. Modifier -91 is not intended to allow you to unbundle those tests and bill each one separately. CPT created this modifier for situations such as you describe, and it should solve your problem. To recover reimbursement for the other two tests you mention, resubmit the claim with documentation supporting the use of modifier -91. Answers to Test Yourself and the Reader Question were provided by Shirley Fullerton, CMBS, CPC, CPC-H, academic director for the Medical Association of Billers in Las Vegas and a coder for MedQuist, a national Internet coding and transcription company based in New Jersey; and Richard Tuck, MD, FAAP, practicing pediatrician with Primecare Pediatrics of Zanesville, Ohio.