Dermatology Coding Alert

Question: Recently I read an article that instructed coders to use the "Rule of Nines" when coding burn treatments. Would you explain this rule?


Wyoming Subscriber

Answer: The Rule of Nines is a way of dividing body surface area (BSA) so physicians can determine what percentage of the body was burned.

If a dermatologist is treating a burned patient after he has been treated in a hospital, the hospital has most likely already used the Rule of Nines to determine what percentage of the body surface was burned. But there are some cases in which a dermatologist would have to determine a burn's size to arrive at a correct ICD-9 code.
 
Medicare bases 948.x (Burns classified according to extent of body surface involved) on the Rule of Nines to estimate the amount of body surface burned.

To code the appropriate fourth and fifth digits, you must know:

• Fourth digit: Percent of total body surface area affected by the burn

• Fifth digit: Percent of body surface with third-degree burns.

CPT breaks down the Rule of Nines like this:

• The head and neck, the right arm, and the left arm each equal 9 percent.

• The back trunk, front trunk, left leg, and right leg each equal 18 percent (the front and back trunk and each leg can be divided into upper and lower segments, each equaling 9 percent).

• The genitalia equal 1 percent.

Example: A patient presents with first-degree burns covering both legs and third-degree burns covering the right arm. Forty-five percent of the total body surface was burned (18 + 18 + 9), and 9 percent has third-degree burns. The correct ICD-9 code is 948.40.

Both Medicare and private payers accept the Rule of Nines, which is the best method for managing and treating burns in any setting. Many CPT manuals have a visual chart illustrating the Rule of Nines; look for it near the "Burns, Local Treatment" subheading (codes 16000-16036).

Answers to You Be the Coder and Reader Questions were reviewed by Linda Martien, CPC, CPC-H, National Healthcare Review in Woodland Hills, Calif.; and Jeffrey Weinberg, MD, director of the Clinical Research Center, Department of Dermatology at St. Luke's-Roosevelt Hospital Center in New York City.