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Tips for Effective Anesthesia Coding for ASCs

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Although the anesthesia section in the CPT manual is the smallest, it can be one of the most difficult areas to accurately code. Not only does the physician have to keep a "tic sheet" of the time, he/she has to document each procedure performed over and above the anesthesia itself. In an outpatient setting, the procedures aren't as severe and/or complicated as those requiring days of hospital stay, but the coding can be just as difficult (if not more so) because of guidelines and modifiers.



For example, Colonoscopy, upper gastrointestinal endoscopy or esophagogastroduodenoscopy (EGD) can pose a problem for anesthesia billing, mainly because most payers consider the conscious sedation anesthesia to be the responsibility of the performing gastroenterologist or endoscopist. Those payers believe the endoscopist can supervise a qualified person to monitor the patient and administer pain meds during the procedure, and that reimbursement is included in the global fee.


In this scenario, and all anesthesia billing, it is very important to verify anesthesia coverage for each patient as Medicare may be more specific as far as reimbursement, and a commercial company may not. A good reference for Medicare is the local coverage determination (LCD) provided by CMS[1]. Commercial companies will vary and therefore accessing the company website or speaking to their representatives is your best option.


Also, use your Anesthesia Coding Crosswalk. If at any time you are uncertain as to what ASA code to use, such as when an EGD and colonoscopy are performed at the same session, verify the surgery code and then reference your crosswalk. Although you can bill either 00740 (EGD) or 00810 (Colonoscopy), a good rule of thumb in this situation is to code the procedure for which a diagnosis is given to support medical necessity.


This brings me to the next suggestion for billing a procedure correctly: Confirm and use the diagnosis code that best supports medical necessity. Your LCD is a good source in this step also because many outpatient procedures require monitored anesthesia care (MAC). When MAC is used, the QS modifier is added to the ASA code and, depending on your geographical area, you would have to use the correct ICD-9 code to support the QS modifier. The anesthesiologist needs to be sure to document MAC, and the medical record needs to support the need for this type of anesthesia. At this point, I must stress: If the diagnosis is not documented in the patient's encounters, you cannot use it!


Do not be afraid to use V codes to support diagnosis. In some anesthesia cases, a V code could be the only accurate primary diagnosis code.


Pre-Op pain medications can pose another obstacle in billing the outpatient surgery anesthesia. For example, CPT 62319, lumbar epidural, can be performed as either post operative pain management or the actual anesthesia. You would need to append modifier 59 to tell the insurance "this is separate from the anesthesia". Documentation from the surgeon stating he/she requested the lumbar epidural for post-op pain is required (Most insurance companies will deny and ask for the documentation for review).


The fourth problem addressed in ASC anesthesia billing would be: use correct modifiers.


Because most knee, shoulder, elbow, etc. diagnostic arthroscopy procedures are done now in ASCs, the request for these pain management procedures is common. If the injection is given before (or even during) the procedure itself, always add the 59 modifier.

Also, the correct pain diagnosis, such as 338.18 Other post operative pain NOS, has to be used as the primary diagnosis for that particular procedure, along with the correct code to support 338.18 (in the case of a knee arthroscopy, this would be the reason for the surgery). A generic code would be 719.46 Pain in joint, lower leg; but remember, the more specific the code, the less likely it is to be questioned.


Finally, Qualifying Circumstance (QC) codes can be used, but unfortunately are usually not billed. There are four QC codes at this time:


99100  Anesthesia for patient of extreme age, younger than 1 year and older than 70

99116  Anesthesia complicated by utilization of total body hypothermia

99135  Anesthesia complicated by utilization of controlled hypotension

99140  Anesthesia complicated by emergency conditions (specify)


(All of these codes are to be listed separately in addition to the ASA code for the primary anesthesia procedure)


Also note that these codes are not recognized by Medicare or Medicaid, but most commercial companies will process them and pay.


In an ASC setting, the only QC codes that would be appropriate for billing would be the 99100 and the 99135. These codes can be billed together under the correct circumstance, such as a 72-yr-old with "severe hypertension," which qualifies him for a modifier P3 Patient with severe systemic disease. If the anesthesiologist uses controlled hypotension during the procedure because of the P3 modifier, you can add 99135 to the claim along with the 99100 (be sure the ASA code descriptor does not specify age when you bill the 99100).


Again: You must have the correct documentation to support any of these billing scenarios.


In conclusion, the three major contributors to coding anesthesia effectively in an ASC are:



As the physician performing the procedure, it is your responsibility to document, LEGIBLY, all facets of the anesthesia provided for each patient. I cannot stress enough the importance of each procedure being recorded and written clearly so that not just your coder can read it, but also any person reviewing and/or auditing your documentation can positively identify any procedure you provided for each patient. Remember: If payment is made on a procedure, money would be recouped if the auditor cannot read the report.



The coder has the responsibility of verifying documentation and procedures performed, and then tying them together for submission to insurance. In essence, you are the fact finder and storyteller. It is imperative that you use the correct codes, modifiers, and times to insure your physician is reimbursed for every procedure he performs in a session. If your physician does his part to document correctly, the next steps for you are to code these procedures correctly and do the research on guidelines, CCI edits, and correct documentation before releasing the claim. The difference between a payable claim and a denied claim can be as simple as an incorrect modifier or diagnosis.


ASC managers

The manager of an ASC has the difficult task of making sure the physicians and coding staff maintain a continuous line of communication. Also, regular audits should be performed so that problem areas can be identified and addressed. Not only does this benefit the professional relationship between physicians and coding staff, but it prepares the facility for audit (which we know can not only be stressful, but costly, if records are incorrect).


If each contributor to the billing process commits themselves to making sure guidelines are met, you can rest assured that your anesthesia procedures will be reimbursed at the highest possible level.


Thank you to the AAPC for providing this column.




The information provided should be utilized for educational purposes only. Facilities are ultimately responsible for verifying the reporting policies of individual commercial and MAC/FI carriers prior to claim submissions.

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