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The diffusing capacity of the lungs, specifically using carbon monoxide (CO), is a critical pulmonary function test that assesses the lungs' ability to transfer gases from inhaled air into the bloodstream. This test is particularly important for evaluating the efficiency of the alveolar-capillary membrane, which is the site where gas exchange occurs. The procedure is designed to differentiate between lung restrictions caused by parenchymal diseases, which affect the lung tissue itself, and those caused by extrapulmonary factors, such as decreased cardiac output. During the test, the patient is required to exhale completely before inhaling a specific gas mixture that includes 0.3 percent carbon monoxide, 10 percent helium, 21 percent oxygen, and 68.7 percent nitrogen. This mixture is delivered through a mouthpiece connected to the diffusion capacity testing device. Once the patient reaches total lung capacity, they hold their breath for a duration of 10 seconds, allowing for optimal gas exchange. After this brief pause, the patient exhales, discarding the initial gas that remains in the conducting airways, which includes the mouth, trachea, and bronchi. The remaining exhaled gas is collected for analysis. The results of this test provide valuable insights into the lung's diffusing capacity, and the physician is responsible for reviewing these results and generating a comprehensive written report detailing the findings.
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The diffusing capacity test using carbon monoxide is indicated for various clinical scenarios where assessment of lung function is necessary. The following conditions may warrant this procedure:
The procedure for measuring the diffusing capacity of the lungs using carbon monoxide involves several key steps that ensure accurate results. Each step is crucial for the integrity of the test.
After the procedure, the patient may resume normal activities immediately, as there are typically no significant post-procedure restrictions. The physician will review the test results, which will be compiled into a written report detailing the findings. This report is essential for further clinical decision-making and may guide subsequent diagnostic or therapeutic interventions based on the patient's pulmonary function status.
| Short Descr | CO/MEMBANE DIFFUSE CAPACITY | Medium Descr | CO DIFFUSING CAPACITY | Long Descr | Diffusing capacity (eg, carbon monoxide, membrane) (List separately in addition to code for primary procedure) | Status Code | Active Code | Global Days | ZZZ - Code Related to Another Service | PC/TC Indicator (26, TC) | 1 - Diagnostic Tests for Radiology Services | Multiple Procedures (51) | 0 - No payment adjustment rules for multiple procedures apply. | Bilateral Surgery (50) | 0 - 150% payment adjustment for bilateral procedures does NOT apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 0 - Payment restriction for assistants at surgery applies to this procedure... | Co-Surgeons (62) | 0 - Co-surgeons not permitted for this procedure. | Team Surgery (66) | 0 - Team surgeons not permitted for this procedure. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | APC Status Indicator | Items and Services Packaged into APC Rates | Type of Service (TOS) | 5 - Diagnostic Laboratory | Berenson-Eggers TOS (BETOS) | T2D - Other tests - other | MUE | 1 | CCS Clinical Classification | 38 - Other diagnostic procedures on lung and bronchus |
This is an add-on code that must be used in conjunction with one of these primary codes.
| 94010 | MPFS Status: Active Code APC Q1 CPT Assistant Article Spirometry, including graphic record, total and timed vital capacity, expiratory flow rate measurement(s), with or without maximal voluntary ventilation | 94060 | MPFS Status: Active Code APC S CPT Assistant Article Bronchodilation responsiveness, spirometry as in 94010, pre- and post-bronchodilator administration | 94070 | MPFS Status: Active Code APC S CPT Assistant Article Bronchospasm provocation evaluation, multiple spirometric determinations as in 94010, with administered agents (eg, antigen[s], cold air, methacholine) | 94375 | MPFS Status: Active Code APC Q1 CPT Assistant Article Respiratory flow volume loop | 94726 | MPFS Status: Active Code APC Q1 Plethysmography for determination of lung volumes and, when performed, airway resistance | 94727 | MPFS Status: Active Code APC Q1 Gas dilution or washout for determination of lung volumes and, when performed, distribution of ventilation and closing volumes | 94728 | MPFS Status: Active Code APC Q1 Airway resistance by oscillometry |
| 26 | Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number. | 59 | Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25. | TC | Technical component; under certain circumstances, a charge may be made for the technical component alone; under those circumstances the technical component charge is identified by adding modifier 'tc' to the usual procedure number; technical component charges are institutional charges and not billed separately by physicians; however, portable x-ray suppliers only bill for technical component and should utilize modifier tc; the charge data from portable x-ray suppliers will then be used to build customary and prevailing profiles | GC | This service has been performed in part by a resident under the direction of a teaching physician | GZ | Item or service expected to be denied as not reasonable and necessary | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | CR | Catastrophe/disaster related | X5 | Diagnostic services requested by another clinician: for reporting services by a clinician who furnishes care to the patient only as requested by another clinician or subsequent and related services requested by another clinician; this modifier is reported for patient relationships that may not be adequately captured by the above alternative categories; reporting clinician service examples include but are not limited to, the radiologist's interpretation of an imaging study requested by another clinician | AQ | Physician providing a service in an unlisted health professional shortage area (hpsa) | 52 | Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use). | GA | Waiver of liability statement issued as required by payer policy, individual case | KX | Requirements specified in the medical policy have been met | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service | GW | Service not related to the hospice patient's terminal condition | Q1 | Routine clinical service provided in a clinical research study that is in an approved clinical research study | XE | Separate encounter, a service that is distinct because it occurred during a separate encounter | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider | Q6 | Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area | 53 | Discontinued procedure: under certain circumstances, the physician or other qualified health care professional may elect to terminate a surgical or diagnostic procedure. due to extenuating circumstances or those that threaten the well being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure was started but discontinued. this circumstance may be reported by adding modifier 53 to the code reported by the individual for the discontinued procedure. note: this modifier is not used to report the elective cancellation of a procedure prior to the patient's anesthesia induction and/or surgical preparation in the operating suite. for outpatient hospital/ambulatory surgery center (asc) reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use). | 76 | Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | UD | Medicaid level of care 13, as defined by each state | 22 | Increased procedural services: when the work required to provide a service is substantially greater than typically required, it may be identified by adding modifier 22 to the usual procedure code. documentation must support the substantial additional work and the reason for the additional work (ie, increased intensity, time, technical difficulty of procedure, severity of patient's condition, physical and mental effort required). note: this modifier should not be appended to an e/m service. | 25 | Significant, separately identifiable evaluation and management service by the same physician or other qualified health care professional on the same day of the procedure or other service: it may be necessary to indicate that on the day a procedure or service identified by a cpt code was performed, the patient's condition required a significant, separately identifiable e/m service above and beyond the other service provided or beyond the usual preoperative and postoperative care associated with the procedure that was performed. a significant, separately identifiable e/m service is defined or substantiated by documentation that satisfies the relevant criteria for the respective e/m service to be reported (see evaluation and management services guidelines for instructions on determining level of e/m service). the e/m service may be prompted by the symptom or condition for which the procedure and/or service was provided. as such, different diagnoses are not required for reporting of the e/m services on the same date. this circumstance may be reported by adding modifier 25 to the appropriate level of e/m service. note: this modifier is not used to report an e/m service that resulted in a decision to perform surgery. see modifier 57 for significant, separately identifiable non-e/m services, see modifier 59. | 56 | Preoperative management only: when 1 physician or other qualified health care professional performed the preoperative care and evaluation and another performed the surgical procedure, the preoperative component may be identified by adding modifier 56 to the usual procedure number. | 77 | Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | 79 | Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.) | 95 | Synchronous telemedicine service rendered via a real-time interactive audio and video telecommunications system: synchronous telemedicine service is defined as a real-time interaction between a physician or other qualified health care professional and a patient who is located at a distant site from the physician or other qualified health care professional. the totality of the communication of information exchanged between the physician or other qualified health care professional and the patient during the course of the synchronous telemedicine service must be of an amount and nature that would be sufficient to meet the key components and/or requirements of the same service when rendered via a face-to-face interaction. modifier 95 may only be appended to the services listed in appendix p. appendix p is the list of cpt codes for services that are typically performed face-to-face, but may be rendered via a real-time (synchronous) interactive audio and video telecommunications system. | CC | Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed) | CS | Cost-sharing waived for specified covid-19 testing-related services that result in and order for or administration of a covid-19 test and/or used for cost-sharing waived preventive services furnished via telehealth in rural health clinics and federally qualified health centers during the covid-19 public health emergency | FS | Split (or shared) evaluation and management visit | GT | Via interactive audio and video telecommunication systems | GX | Notice of liability issued, voluntary under payer policy | GY | Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit | JZ | Zero drug amount discarded/not administered to any patient | PD | Diagnostic or related non diagnostic item or service provided in a wholly owned or operated entity to a patient who is admitted as an inpatient within 3 days | Q0 | Investigational clinical service provided in a clinical research study that is in an approved clinical research study | Q5 | Service furnished under a reciprocal billing arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area | QJ | Services/items provided to a prisoner or patient in state or local custody, however the state or local government, as applicable, meets the requirements in 42 cfr 411.4 (b) | SA | Nurse practitioner rendering service in collaboration with a physician | TL | Early intervention/individualized family service plan (ifsp) | TQ | Basic life support transport by a volunteer ambulance provider | X1 | Continuous/broad services: for reporting services by clinicians, who provide the principal care for a patient, with no planned endpoint of the relationship; services in this category represent comprehensive care, dealing with the entire scope of patient problems, either directly or in a care coordination role; reporting clinician service examples include, but are not limited to: primary care, and clinicians providing comprehensive care to patients in addition to specialty care | XP | Separate practitioner, a service that is distinct because it was performed by a different practitioner |
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| 2013-01-01 | Changed | Description Changed |
| 2012-01-01 | Added | Added |
| 2011-11-30 | Changed | Short descriptor changed for 2012 per Corrections Notice 2012 |
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