Crucial Factors to Consider When Coding for
General Anesthesia Services
Anesthesia charges are calculated on the basis of factors such as the complexity of the procedure, its duration and modifying factors such as the patient’s health and where the service is provided. In Anesthesia medical billing, you must take into consideration the base value units, time units and the modifying units. The total anesthesia charge is calculated by multiplying the total number of units (base units + time units + modifying units) with the conversion factor (dollar amounts specified for a particular geographic area). Base Value Units The American Society of Anesthesiologists (ASA) Relative Value Guide assigns a basic value to the anesthetic management of surgical procedures. The base unit indicates how hard the anesthesia procedure is to perform and how much skill is required. The more difficult the procedure, the higher the base units. If multiple surgical procedures are performed under a single anesthetic, the value of the procedure with the highest number of base units should be reported as the base value. The base value includes all usual anesthesia services such as usual pre- and post-operative visits, the interpretation of noninvasive monitoring (for instance ECG, oximetry, capnography) and administration of fluids and/or blood products incident to anesthesia care. Time Units The time taken to provide anesthesia (anesthesia time) is expressed as ‘Time Units’. Anesthesia time starts when the anesthesia provider starts to prepare the relevant patient for anesthesia induction (typically in the case of intravenous access) and stops when that patient is no longer provided personal attendance (the patient is placed safely under postoperative supervision). Though the basic ‘Time Units is normally considered to be 15 minutes, the definition may vary according to the insurance carrier (for instance, some may consider 10 minutes as basic ‘Time Unit’). It is best to clarify with the incurrence carriers how they define the time units and how they prefer them to be reported.
The HIPAA Electronic Transaction Standard 5010 does not accept units, but requires total anesthesia time to be reported on the claim form under the column ‘Units’. In the CMS 1500 form, the anesthesia units can be reported in the field under 24G ‘Day or Units’ box. Normally, anesthesia services must be reported in minutes in this form. Units may be reported only if the code description of relevant anesthesia service includes a time period. Modifying Units The modifying unit indicates the special conditions that may affect the anesthesia procedure, or provides additional information that is not specified by the procedure code. Different types of modifying units for general anesthesia services are: HCPCS Level II Modifiers Sometimes, the operating surgeon may request general anesthesia services and a CRNA (Certified Registered Nurse Anesthetist) or a physician other than the surgeon to provide the services; or sometimes the operating surgeon may perform the sedation procedure as part of a surgical or diagnostic procedure. In Medicare, the payment for general anesthesia administered or supervised by the operating surgeon is bundled. HCPCS Level II modifiers are used to indicate whether anesthesia services are performed by anesthesiologists or CNRA and other additional information about the services (medical direction and medical supervision). Modifiers Used By Anesthesiologists
AA: Anesthesia services performed personally by anesthesiologist
AD: Medical supervision by a physician (anesthesiologist); more than four concurrent anesthesia procedures
QK: Medical direction (supervision) of two, three or four concurrent anesthesia procedures
QY: Anesthesiologist medically directs one CRNA
Modifiers Used By Certified Registered Nurse Anesthetists (CRNAs)
QX: CRNA service with medical direction (supervision) by a physician
QZ: CRNA service without medical direction (supervision) by a physician
Physical Status Modifiers These modifiers are used to specify the health conditions of the patient at the time of providing anesthesia or simply the complex levels of anesthesia services. This modifier should be reported only with the CPT codes that report anesthesia services (00100-01999), and should be placed after the HCPCS Level II modifiers (for example, 25270-AA-P2).
P1: Normal healthy patient (0 value unit)
P2: Patient with mild systemic disease (1 value unit)
P3: Patient with severe systemic disease (2 value units)
P4: Patient with severe systemic disease that is a constant threat to life (3 value units)
P5: Moribund patient, not expected to survive with-out the operation (0 value unit)
P6: Declared brain-dead patient whose organs are being removed for donor purposes (0 value unit)
Qualifying Circumstances Codes denoting qualifying circumstances describe the anesthesia services provided under difficult or unusual circumstances. Anesthesia time and modifiers are not required along with qualifying circumstances codes. Reporting these in addition to the anesthesia code, may qualify for additional reimbursement (depending on the carrier). They may be reported along with more than one CPT code.
+99100: Anesthesia for patient of extreme age, under one year or over 70 (1 value unit)
+99116: Anesthesia complicated by utilization of total body hypothermia (5 value units, additional units are permitted in rare cases)
+99135: Anesthesia complicated by utilization of controlled hypotension (5 value units)
+99140: Anesthesia complicated by emergency conditions (2 value units)
An emergency exists when there is a treatment delay which would lead to considerable increase in the threat to a patient’s life or body part. Specialized Monitoring and Other Miscellaneous Procedures Though used to describe additional procedures/services, these are not technically modifiers and are used along with anesthesia codes in special cases. No anesthesia time and modifiers are required or needed to be reported with these codes.
36000: Induction of needle or intracatheter, vein (5 Value Units)
36010: Introduction of catheter, superior or inferior vena cava (5 Value Units)
36014: Pulmonary artery line (7 Value Units)
36400: Venipuncture, under age 3 years, femoral, jugular or sagittal sinus (2 Value Units)
36410: Venipuncture, over age 3 years or adult, necessitating physician's skill (1 Value Unit)
36420: Venipuncture, cutdown, under age 1 year (5 Value Units)
36425: Venipuncture, cutdown, age 1 or over (3 Value Units)
36555: Insertion of non-tunneled centrally inserted central venous catheter; under 5 years of age (5 Value Units)
36556: Insertion of non-tunneled centrally inserted central venous catheter; age 5 years or older (4 Value Units)
36600: Arterial puncture, withdrawal of blood for diagnosis (1 Value Unit)
36620: Insertion of an arterial line; percutaneous (3 Value Units)
36625: Insertion of an arterial line; cutdown (5 Value Units)
36660: Catheterization, umbilical artery, newborn for diagnosis or therapy (5 Value Units)
documentation (2D) (with or without M-mode recording); including probe placement, image acquisition, interpretation and report (6 Value Units)
documentation; placement of transesophageal probe only (2 Value Units)
documentation (2D) (with or without M-mode recording); image acquisition, interpretation and report only (4 Value Units)
93315: Transesophageal echocardiography for congenital cardiac anomalies; including probe placement, image acquisition, interpretation and report (8 Value Units)
93316: Transesophageal echocardiography for congenital cardiac anomalies; placement of transesophageal probe only (3 Value Units)
93317: Transesophageal echocardiography for congenital cardiac anomalies; image acquisition, interpretation and report only (5 Value Units)
93318: Echocardiography, transesophageal (TEE) for monitoring purposes, including probe placement, real time 2-dimensional image acquisition and interpretation leading to ongoing (continuous) assessment of (dynamically changing) cardiac pumping function and to therapeutic measures on an immediate time basis (6 Value Units)
93503: Insertion and placement of flow directed catheter (e.g. Swan-Ganz) (10 Value Units)
The allowable charges for general anesthesia are calculated by the formula (Anesthesia Base Units + Anesthesia Time Units + Physical Status Modifier + Qualifying Circumstances + Specialized Monitoring) x Anesthesia Conversion Factor. Anesthesiology medical coding and billing is distinct from that of other specialties that focus on fee-for-service payment. Reliable and dedicated support from a professional medical billing and coding company can ensure accurate general anesthesia coding and billing.
Published on Feb 14, 2014
Learn more about the three main factors that need to be considered in anesthesia medical billing and coding.