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The CPT® Code 85300 refers to a laboratory test that measures the activity of antithrombin III, a critical protein in the regulation of blood coagulation. Antithrombin III functions as a natural anticoagulant, inhibiting the activity of several enzymes in the coagulation cascade, particularly thrombin and factor Xa. This test is essential for evaluating the anticoagulant properties of a patient's blood, especially in cases where there is a suspicion of clotting disorders or when monitoring patients on anticoagulant therapy. The procedure involves taking a diluted blood sample and mixing it with antithrombin-deficient plasma, which contains the necessary intrinsic coagulation enzymes. An AT augmenting compound, such as heparin, is also added, along with phospholipids and an activator that initiates the contact phase of the intrinsic coagulation pathway. After the addition of calcium ions, the coagulation time is measured and compared to a reference standard, allowing for the determination of the antithrombin III activity level in the sample. This test is crucial for diagnosing conditions related to abnormal clotting and for managing patients who may be at risk for thromboembolic events.
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The CPT® Code 85300 is indicated for use in various clinical scenarios where the assessment of antithrombin III activity is necessary. The following conditions may warrant this test:
The procedure for CPT® Code 85300 involves several critical steps to accurately measure the activity of antithrombin III in a blood sample. The following steps outline the process:
After the completion of the procedure associated with CPT® Code 85300, there are several considerations for post-procedure care and interpretation of results. The laboratory will analyze the coagulation time obtained from the test and compare it to established reference ranges. Results indicating low antithrombin III activity may suggest a deficiency that could predispose the patient to thrombotic events. It is essential for healthcare providers to interpret the results in conjunction with the patient's clinical history and other laboratory findings. Follow-up testing or additional evaluations may be necessary based on the results. Patients may not require any specific post-procedure care, but it is important to monitor for any signs of bleeding or clotting complications, especially if the test is part of a broader evaluation for coagulation disorders.
| Short Descr | ANTITHROMBIN III ACTIVITY | Medium Descr | CLOTTING INHIBITORS ANTITHROMBIN III ACTIVITY | Long Descr | Clotting inhibitors or anticoagulants; antithrombin III, activity | Status Code | Statutory Exclusion (from MPFS, may be paid under other methodologies) | Global Days | XXX - Global Concept Does Not Apply | PC/TC Indicator (26, TC) | 9 - Not Applicable | Multiple Procedures (51) | 9 - Concept does not apply. | Bilateral Surgery (50) | 9 - Concept does not apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 9 - Concept does not apply. | Co-Surgeons (62) | 9 - Concept does not apply. | Team Surgery (66) | 9 - Concept does not apply. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | CLIA Waived (QW) | No | APC Status Indicator | Conditionally packaged laboratory tests | Type of Service (TOS) | 5 - Diagnostic Laboratory | Berenson-Eggers TOS (BETOS) | T1H - Lab tests - other (non-Medicare fee schedule) | MUE | 2 | CCS Clinical Classification | 233 - Laboratory - Chemistry and Hematology |
| 90 | Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number. | 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. | 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. | 91 | Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient. | GA | Waiver of liability statement issued as required by payer policy, individual case | 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 | GZ | Item or service expected to be denied as not reasonable and necessary | Q1 | Routine clinical service provided in a clinical research study that is in an approved clinical research study | Q4 | Service for ordering/referring physician qualifies as a service exemption |
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| 2013-01-01 | Changed | Short Descriptor changed. |
| Pre-1990 | Added | Code added. |
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