Subject	Medically unlikely edits and the use of the ABN
Source	AAOMS Newsletter
Publication	Coding Corner Sept/Oct. 2009
Effective Date	Sep 1, 2009
Publish Date	Sep 1, 2009

Medically unlikely edits and the use of the ABN

On January 1, 2007, the Centers for Medicare and Medicaid Services (CMS) began a phased implementation of billing edits called MUEs (Medically Unlikely Edits) designed to stop inappropriate payments by detecting and denying unlikely claims. These edits are based on anatomic considerations, CPT code descriptors/CPT coding instructions, CMS policies, nature of procedure/service, nature of analyte, nature of equipment or clinical judgment. While the majority apply to CPT codes, some edits apply to HCPCS Level II codes.

While the CCI (Correct Coding Initiative) edits compare codes on different lines of the claim form, the MUEs look at the units of service (UOS) reported per code. The MUEs place maximums on the number of UOS per code that can be reported by a provider for the same beneficiary on the same date of service. Any line of the claim form where the UOS is exceeded will be denied. Watch for remark code N362: "the number of days or units of service exceeds our acceptable maximum" to signal that a claim may have triggered a MUE.

The utilization of MUEs has made it increasingly important to include the correct modifiers on claims so that services that are separately billable are not inappropriately bundled. The correct method of billing the same service twice is on two separate lines of the claim form with an appropriate modifier on the second listing of the code. Remember that documentation must support the use of the modifier.

CMS has recently reminded providers that the use of the Advance Beneficiary Notice of Noncoverage (ABN) form in no way permits balance billing of a patient for units of service denied due to a MUE. According to the December 8, 2006 CMS CR5402 (http://www.cms.hhs.gov/MLNMattersArticles/downloads/MM5402.pdf): "Excess charges due to units of service greater than the MUE may not be billed to the beneficiary (this is a "provider liability") and this provision can neither be waived nor subject to an Advanced Beneficiary Notice (ABN)."

For more information visit the Practice Management pages at aaoms.org and the CMS web site at http://www.cms.hhs.gov/NationalCorrectCodInitEd/08_MUE.asp#TopofPage.