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Test Code 037 Activated Clotting Time (ACT)

Important Note

Requests for ACT testing other than for cardiac patients must be processed through a pathologist by the primary care physician.

Anticoagulation Fact Sheet for Clinical Monitoring

Additional Codes


PowerChart: Activated Clotting Time

Epic: LAB312 Activated Clotting Time

Test Method

Kaolin activated clotting time; Abbott i-STAT

Specimen Requirement

0.5 mL whole blood is required.

Additional Specimen Collection Information

Two possible acquisition methods are acceptable:

Venipuncture: Using a syringe.  Arterial or Venous Line:

The specimen may be collected by nursing personnel from an arterial or venous line.


Performed by laboratory personnel at the patient bedside.

Reference Values

Reference values are established by the cardiologists or clinicians pertinent to the clinical situation.

Non-heparinized patients: 74-137 sec.

CPT Code Information

85347 Coagulation time, Lee and White, activated

Useful For

The ACT is an indirect assessment of the efficacy of heparin in surgical procedures. Initial measurements determine sufficient heparin dose administration. Subsequent measurements are used to determine if the heparin dose has been sufficiently neutralized.


3184-9 Activated Clotting Time In Blood By Coagulation Assay