Anesthesia Coding Alert

Question: How should I bill 99144? I have been getting denied for "Invalid unit/basis meas. Code" or "Illogical Quantity." How can I fix this?

Oklahoma Subscriber

Answer: The standards for time measurement provided in the CPT®’s introduction apply to all situations unless the book lists code-specific instructions in the guidelines, parenthetical instructions, or code descriptors to contrary. CPT® does not include any code-specific guidelines for the moderate (conscious) sedation codes, the general guidelines are to be applied in this instance. A unit of time is attained when the midpoint has been passed.

Code 99144 (Moderate sedation services [other than those services described by codes 00100-01999] provided by the same physician or other qualified health care professional performing the diagnostic or therapeutic service that the sedation supports, requiring the presence of an independent trained observer to assist in the monitoring of the patient’s level of consciousness and physiological status; age 5 years or older, first 30 minutes intra-service time) represents a 30-minute block of time. Therefore, the provider must provide moderate sedation to the patient for 16 minutes or more to reach the midpoint of the service as described by the code. If the time threshold isn’t met, you shouldn’t report the conscious sedation service.

Support: CPT® Assistant (October 2011) confirms that these time guidelines apply to the moderate sedation codes. Payer guidelines may differ from (and trump) CPT® guidelines for their own claims, but at least one Medicare Administrative Contractor (MAC) has instructed its providers to follow the midpoint rule. Part B MAC NGS posted "Time Requirement to Report Moderate Sedation" as a Feb. 21, 2012, news article on its site. The notice also states, "When no written policy exists Medicare does follow CPT® guidelines."

Keep in mind: Many cardiology codes are listed in CPT® Appendix G indicating that moderate sedation is included in the code. For those codes, you should not report moderate sedation codes separately.