Radiology Coding Alert

Question: How many guidance codes may I use per encounter? For example, if the patient has ultrasound guidance for thoracentesis and then ultrasound guided paracentesis, may I report guidance twice or only once?

Texas Subscriber

Answer: If you're receiving denials, one possibility is that you're running up against medically unlikely edits (MUEs) from Medicare. If you check the list of practitioner MUEs, you'll find that many guidance codes have a limitation of one unit.

For example, 76942 (Ultrasonic guidance for needle placement [e.g., biopsy, aspiration, injection, localization device], imaging supervision and interpretation) is listed with an MUE of 1. That means if you report more than one unit of 76942 for a single beneficiary on a single service date, you'll get a denial.

Modifier GD: CMS states that you should rarely exceed the limits, but when the radiologist performs and documents a medically necessary number of services that exceed MUEs, check your payer's reporting preference. HCPCS offers modifier GD (Units of service exceeds medically unlikely edit value and represents reasonable and necessary services). But there is little information available on proper use of this modifier.

Other payers may prefer that you report the guidance codes on separate lines and choose modifier 59 (Distinct procedural service), modifier 76 (Repeat procedure by same physician), or other modifiers to indicate the separate nature of the services. You also may need to supply documentation showing medical necessity for the additional units.

CMS does not publish all MUEs, but published edits are available on the same CMS Web page as Correct Coding Initiative edits: http://www.cms.hhs.gov/NationalCorrectCodInitEd/08_MUE.asp#TopOfPage.