What Is a STAT Test?
STAT tests are laboratory tests ordered and performed immediately because a delay in results could directly compromise patient care or clinical decision-making. The term comes from the Latin statim, meaning “immediately.” In clinical laboratory practice, STAT is the highest-priority designation, placing a test ahead of all routine and urgent orders in the processing queue.
STAT status is triggered by clinical need — typically in emergency departments (EDs), intensive care units (ICUs), operating rooms, trauma bays, and labor and delivery units. When a physician orders a STAT test, the laboratory prioritizes every step: specimen collection, transport, processing, analysis, and result reporting.
Understanding STAT testing matters beyond the bedside. For clinical laboratories, reference labs, and point-of-care testing networks, STAT capability is a core performance metric monitored by regulatory and accreditation bodies including the Centers for Medicare and Medicaid Services (CMS) under CLIA, the College of American Pathologists (CAP), and The Joint Commission. For laboratory managers and healthcare system administrators, STAT turnaround time (TAT) is a key quality indicator tied to patient outcomes and accreditation compliance. Find out more about STAT TAT benchmarks in our guide to laboratory turnaround time.
STAT vs. Urgent vs. Routine: Key Differences
Not every elevated-priority lab order is STAT. Clinical laboratories operate a three-tier prioritization system:
| Priority | Definition | Typical TAT target | Clinical setting |
| STAT | Immediate — highest priority. All other specimens deferred. | 15-60 minutes depending on test; cardiac troponin consensus target: <60 min | Emergency department, ICU, trauma, OR, labor & delivery, acute deterioration on ward |
| Urgent | Elevated priority but not immediate. Processed ahead of routine. | 1-4 hours | Admitted inpatients with acute but not immediately life-threatening findings |
| Routine | Standard processing, no clinical urgency. | 24-48 hours or next scheduled reporting | Outpatient, pre-operative screening, chronic disease monitoring (e.g., quarterly HbA1c for diabetes) |
Note on HbA1c: A common misconception is that HbA1c (hemoglobin A1c) is a STAT test. It is not. HbA1c reflects average blood glucose over the preceding 2-3 months and cannot reflect a patient’s acute glycemic status. For emergency glucose assessment, clinicians order point-of-care blood glucose or a blood glucose panel — results available in minutes — not HbA1c. HbA1c is a routine monitoring test ordered every 3 months for diabetes management.
Complete STAT Test Quick-Reference Table
The following table covers the most commonly ordered STAT tests in emergency and critical care settings, with typical clinical context, what the result indicates, and standard TAT targets.
| Test | Measures | Key clinical indication | Typical STAT TAT |
| Complete Blood Count (CBC) | RBCs, WBCs, hemoglobin, hematocrit, platelets, differential | Infection, anemia, bleeding, leukemia, thrombocytopenia; screens for sepsis in conjunction with clinical assessment | 30-45 min (central lab); 2-5 min (POC hematology analyzer) |
| Blood glucose | Plasma or whole blood glucose concentration | Hypoglycemia (<70 mg/dL) or hyperglycemia / diabetic ketoacidosis (DKA); glucose monitoring in critically ill patients | <5 min (POC glucometer, CLIA-waived); 15-30 min (central lab) |
| Electrolyte panel (BMP/CMP) | Sodium, potassium, chloride, CO2/bicarbonate; with creatinine, BUN, glucose in BMP; adds LFTs in CMP | Cardiac arrhythmia risk (K+, Mg2+); renal failure; acid-base disturbance; medication safety (digoxin toxicity needs K+) | 30-45 min (central lab); 10-15 min (POC analyzer) |
| Troponin I or T (conventional) | Cardiac troponin I or T — released from damaged cardiomyocytes | Acute myocardial infarction (AMI) rule-in; serial measurement at 0h and 3-6h; chest pain evaluation | <60 min from order to result (ACC/AHA consensus target) |
| High-sensitivity troponin (hs-cTnI/T) | Cardiac troponin at 10-100x greater analytical sensitivity than conventional assays; detects pg/mL concentrations | Rapid AMI rule-out using 0/1h or 0/2h protocols (ESC 2023 guidelines); earlier detection than conventional troponin | <60 min; 0/1h protocol allows AMI rule-out at 1 hour in low-risk patients |
| Arterial blood gas (ABG) | pH, pO2, pCO2, HCO3-, O2 saturation, base excess | Respiratory failure; ventilator management; acid-base disorders (metabolic vs. respiratory acidosis/alkalosis); CO2 retention | 15-30 min (central lab); 2-5 min (POC blood gas analyzer) |
| Lactate | Blood lactate concentration (venous or arterial) | Sepsis severity (>2 mmol/L = possible sepsis; >4 mmol/L = septic shock per Sepsis-3 criteria); tissue hypoperfusion; shock of any type; serial measurement to monitor treatment response | 30-45 min (central lab); 10-15 min (POC) |
| Procalcitonin (PCT) | Serum PCT — pro-hormone of calcitonin, rises specifically in bacterial infections and sepsis | Sepsis biomarker (>0.5 ng/mL elevated concern; >2 ng/mL high probability sepsis); antibiotic stewardship guidance; Surviving Sepsis Campaign-endorsed biomarker | 30-60 min (central lab immunoassay) |
| PT/INR | Prothrombin time; International Normalized Ratio | Anticoagulant monitoring (warfarin therapy); liver function (coagulation factor synthesis); bleeding disorder workup; pre-procedure assessment | 30-45 min (central lab); <5 min (POC coagulation, e.g., CoaguChek) |
| aPTT | Activated partial thromboplastin time — intrinsic and common coagulation pathway | Heparin therapy monitoring; hemophilia A/B; factor deficiency workup; lupus anticoagulant screen | 30-45 min (central lab) |
| D-dimer | Fibrin degradation product; elevated when fibrinolysis is active | DVT/PE rule-out in low-to-intermediate pretest probability (Wells score); disseminated intravascular coagulation (DIC); COVID-associated coagulopathy | 30-60 min (central lab immunoassay) |
| BNP / NT-proBNP | B-type natriuretic peptide / N-terminal pro-BNP — biomarkers of myocardial wall stress | Heart failure diagnosis and severity stratification; acute dyspnea differentiation (cardiac vs. pulmonary); prognosis in acute decompensated heart failure | 30-60 min (central lab) |
| Creatinine / eGFR | Serum creatinine; estimated glomerular filtration rate calculated from creatinine | Acute kidney injury (AKI) diagnosis and staging; contrast-induced nephropathy risk assessment; medication dosing (renally-cleared drugs); ICU monitoring | 30-45 min (central lab, included in BMP/CMP) |
| Ammonia | Blood ammonia — a waste product cleared by a healthy liver | Hepatic encephalopathy (acute or chronic liver failure); altered mental status in suspected liver disease; monitoring in urea cycle disorders | 30-60 min (central lab — specimen must be transported on ice and processed immediately) |
| Calcium (total and ionized) | Total serum calcium; free ionized calcium (Ca2+) measured directly in blood gas analyzers | Hypercalcemia (malignancy, hyperparathyroidism); hypocalcemia (post-thyroidectomy, hypomagnesemia, massive transfusion); cardiac arrhythmia risk | 30-45 min (total, central lab); 2-5 min (ionized, POC blood gas) |
| Magnesium | Serum magnesium concentration | Cardiac arrhythmia (hypomagnesemia can cause torsades de pointes and AF); eclampsia monitoring; management of severe asthma with IV magnesium | 30-45 min (central lab) |
| Blood culture | Blood ammonia — a waste product cleared by healthy liver | Sepsis, bacteremia, endocarditis workup; febrile neutropenia; must be collected (ideally 2 sets, >10 mL blood each) BEFORE antibiotic administration — time-critical collection even if organism ID takes days | Collection and incubation initiation: immediate. Positive flag: typically 6-24 hours. Full ID and sensitivities: 24-72+ hours |
| Type & screen / crossmatch | ABO/Rh blood type; antibody screen; crossmatch with specific donor units | Trauma with hemorrhage; surgery with expected blood loss; obstetric emergencies; massive transfusion protocol activation | Type & screen: 45-60 min. Emergency release O-negative: immediate (no testing). Electronic crossmatch: 5-10 min after type confirmed |
Key STAT Tests in Clinical Context
High-Sensitivity Cardiac Troponin (hs-cTn): The Modern Standard
Conventional cardiac troponin assays detect myocardial injury reliably but require serial measurements at 0 and 3-6 hours to rule in or rule out acute MI with confidence. High-sensitivity cardiac troponin (hs-cTnI and hs-cTnT) assays detect troponin at concentrations 10-100 times lower than conventional assays, enabling earlier detection of myocardial injury and — critically — enabling rapid rule-out protocols
The European Society of Cardiology (ESC) 2023 NSTE-ACS guidelines recommend a 0/1 hour (0h and 1h) or 0/2 hour serial hs-cTn protocol as the preferred strategy for rule-out and rule-in of acute MI. For patients with hs-cTn at or below the limit of detection at 0 hours and a very low 1-hour absolute change, AMI can be ruled out in approximately 60 minutes, enabling early discharge from the ED. The FDA cleared the first hs-cTnI assay in the US in 2017, and hs-cTn is now the standard in most major US health systems. The STAT TAT target for hs-cTn remains the same as conventional troponin: results available within 60 minutes of order.
Procalcitonin and Lactate: The Sepsis Biomarker Pair
The Surviving Sepsis Campaign and most sepsis bundles now recommend measuring both lactate and procalcitonin (PCT) in the initial STAT workup of suspected sepsis. These two biomarkers provide complementary information:
- Lactate reflects tissue hypoperfusion and metabolic dysfunction from any cause — sepsis, hemorrhagic shock, cardiac arrest, ischemia, or severe hypoxia. Lactate is sensitive to hemodynamic compromise but not specific to infection. Per Sepsis-3 criteria, lactate >2 mmol/L in the presence of suspected infection defines sepsis, and lactate >4 mmol/L defines septic shock.
- Procalcitonin (PCT) rises specifically in response to systemic bacterial infection and sepsis, with minimal elevation in viral infections, non-infectious systemic inflammation (SLE, pancreatitis), and most localized infections. This specificity makes PCT valuable for antibiotic stewardship — both initiating antibiotic therapy and guiding de-escalation as PCT falls with treatment response. PCT >0.5 ng/mL suggests possible bacterial infection; >2 ng/mL is associated with high probability of sepsis; serial PCT-guided protocols have demonstrated reduced antibiotic exposure without worse outcomes in multiple randomized trials.
Point-of-Care STAT Testing: Speed at the Bedside
Not all STAT tests run through the central hospital laboratory. A substantial and growing proportion of STAT testing occurs at the point of care (POC) — at the patient’s bedside, in the ED triage bay, in the ambulance, or in satellite ICU laboratories — using portable or benchtop POC analyzers. POC STAT testing achieves drastically shorter TATs than central laboratory processing:
- Blood glucose by POC glucometer: <5 minutes (CLIA-waived)
- ABG on POC blood gas analyzer (e.g., Abbott i-STAT, Radiometer ABL): 2-5 minutes
- Ionized calcium, sodium, potassium, lactate on combined blood gas/chemistry POC: 2-5 minutes
- PT/INR on POC coagulation analyzer: <5 minutes (CLIA-waived for some platforms)
POC testing is governed by the same CLIA regulations as central laboratory testing. Most high-complexity POC testing requires at minimum a CLIA certificate for moderate or high complexity, with quality control, proficiency testing, and competency assessment requirements. CLIA-waived tests (FDA-approved simple tests with minimal risk of error) can be performed with a CLIA certificate of waiver — a streamlined certification. For more on CLIA requirements for clinical laboratories, see our guide to CLIA certification.
STAT Testing, CLIA, and Laboratory Accreditation
For clinical laboratories offering STAT services, meeting TAT commitments is not just a customer service concern — it is an accreditation requirement. Both the College of American Pathologists (CAP) and The Joint Commission (TJC) require laboratories to: (1) define STAT TAT standards for each test category; (2) measure and document actual STAT TAT performance; (3) investigate and report STAT TAT outliers; and (4) implement improvement plans when TAT performance falls below standards.
The Clinical Laboratory Improvement Amendments (CLIA) set the federal quality standards framework within which all STAT testing must operate. Every laboratory performing non-waived STAT testing must maintain appropriate CLIA certification (moderate or high complexity), with requirements for personnel qualifications, quality control, method validation, and proficiency testing. Laboratories performing POC STAT testing across a health system must maintain oversight of all POC devices, including QC documentation and staff competency records at each device location.
STAT Testing Capabilities: What to Look for in a Clinical Testing Partner
For healthcare systems, research organizations, pharmaceutical companies running clinical trials, and medical device manufacturers testing diagnostic platforms, STAT testing capability is a critical criterion when selecting a laboratory partner. Key capabilities to verify:
- Defined and documented STAT TAT commitments per test category, with historical performance data available on request.
- 24/7 STAT capability — STAT testing must be available around the clock. Verify that staffing, instrument access, and result reporting systems operate continuously, not only during business hours.
- CLIA certification at the appropriate complexity level — moderate for common chemistry panels; high complexity for specialized testing. Confirm the certificate is current and covers the specific test menu required.
- CAP accreditation or Joint Commission laboratory accreditation — these voluntary but widely recognized accreditations provide independent verification that the laboratory’s STAT processes meet rigorous quality standards.
- Point-of-care testing network management capability — for healthcare systems deploying POC STAT devices across multiple locations, look for laboratory partners who can manage POC device QC, reagent supply, and CLIA compliance across the network.
- Validated reference intervals and critical value notification protocols — STAT tests require defined critical value thresholds (e.g., K+ >6.5 mEq/L, glucose <40 mg/dL) and rapid notification procedures to the ordering clinician. Confirm these protocols are documented and practiced.
ContractLaboratory.com connects healthcare organizations, clinical research teams, medical device manufacturers, and laboratory managers with accredited medical and clinical testing laboratories capable of meeting STAT testing requirements. Whether you need a laboratory for clinical trial sample processing with STAT turnaround commitments, a reference laboratory for specialized STAT panels, or a partner for POC device validation and CLIA compliance support, submit a lab testing request describing your STAT testing requirements. Qualified laboratories with verified capabilities will respond. For direct assistance, contact our team.
Frequently Asked Questions About STAT Laboratory Tests
STAT comes from the Latin statim, meaning “immediately.” In clinical laboratory practice, STAT is the highest test priority designation, indicating that the specimen must be processed and results delivered as quickly as possible — ahead of all routine and urgent orders. STAT status is assigned when a delay in test results could directly affect immediate clinical decision-making, such as in emergency departments, ICUs, trauma bays, or operating rooms. Laboratories define specific STAT turnaround time (TAT) targets for each test — typically 15-60 minutes from specimen receipt to result, depending on the test. CAP and The Joint Commission require laboratories to document and monitor STAT TAT performance.
No. HbA1c (hemoglobin A1c or glycated hemoglobin) is a routine monitoring test, not a STAT test. HbA1c reflects average blood glucose concentration over the preceding 2-3 months — it cannot reveal a patient’s immediate glycemic status. In acute or emergency situations where blood glucose must be known immediately (hypoglycemia, diabetic ketoacidosis, hyperglycemic hyperosmolar state), clinicians order point-of-care blood glucose or a blood glucose panel with results in minutes. HbA1c is ordered every 3 months in outpatient diabetes management — it is explicitly categorized as a routine test by clinical laboratory guidelines.
STAT turnaround time varies by test and whether it is performed in the central laboratory or at the point of care. Approximate targets: point-of-care glucose takes under 5 minutes; arterial blood gas (POC) takes 2-5 minutes; complete blood count takes 30-45 minutes in the central lab; cardiac troponin and high-sensitivity troponin have a consensus target of under 60 minutes from order to result per ACC/AHA guidelines; basic metabolic panel takes 30-45 minutes; lactate takes 30-45 minutes in the central lab. CAP and The Joint Commission require laboratories to define, track, and report compliance with their STAT TAT standards.
High-sensitivity cardiac troponin (hs-cTnI or hs-cTnT) assays detect cardiac troponin at concentrations 10-100 times lower than conventional troponin assays — measuring in picograms per milliliter vs. nanograms per milliliter. This analytical sensitivity enables two major advances. First, myocardial injury can be detected earlier after onset — within 1-2 hours of symptom onset vs. 3-6 hours with conventional troponin. Second, validated rapid rule-out protocols (0/1h and 0/2h protocols endorsed by the 2023 ESC NSTE-ACS guidelines) allow acute MI to be confidently excluded in low-risk patients after just one or two hs-cTn measurements, enabling safe early discharge from the ED. The FDA cleared the first hs-cTnI assay in the US in 2017.
Procalcitonin (PCT) is a biomarker that rises specifically in response to systemic bacterial infections and sepsis, with minimal elevation in viral infections or non-infectious inflammation. It is ordered STAT in the emergency sepsis workup — typically alongside blood cultures, lactate, CBC, and metabolic panel — when sepsis is clinically suspected. PCT levels help guide antibiotic therapy initiation and de-escalation: values >0.5 ng/mL suggest bacterial infection; >2 ng/mL strongly supports sepsis. Serial PCT measurements during treatment reflect treatment response. The Surviving Sepsis Campaign and IDSA antibiotic stewardship guidelines both recognize PCT as a validated biomarker for sepsis management and antibiotic decision-making.
Point-of-care (POC) STAT testing refers to laboratory testing performed at or near the patient’s location — at the bedside, in the ED triage area, in the ICU, or in an ambulance — using portable or compact analyzers, rather than sending specimens to the central hospital laboratory. Common POC STAT platforms include the Abbott i-STAT (blood gas, chemistry, coagulation), Roche cobas b 123 (blood gas), and various POC troponin platforms. POC STAT testing achieves dramatically shorter TATs (2-15 minutes for most tests) compared to central lab STAT (30-60 minutes). POC testing is regulated by CLIA — devices and tests must have appropriate CLIA complexity classification, and the laboratory must maintain quality control, proficiency testing, and staff competency documentation for all POC devices, even those using CLIA-waived platforms.
Blood cultures are STAT because the critical action is the collection, not the result readout. The Surviving Sepsis Campaign’s Hour-1 Bundle specifies that blood cultures must be collected before antibiotic administration, and that antibiotics should begin within one hour of sepsis recognition. Every minute of delay in specimen collection and antibiotic initiation in septic shock increases mortality risk. Once collected, the blood culture bottles enter automated incubation systems and are monitored continuously for bacterial growth — a positive flag typically appears within 6-24 hours for common organisms. Full organism identification and antibiotic sensitivities then take an additional 24-72 hours. So while the final result takes days, the STAT urgency applies to the collection workflow, which must happen immediately and before antibiotics are started.
CLIA (Clinical Laboratory Improvement Amendments of 1988) establishes federal quality standards for all laboratory testing performed on human specimens in the US. Laboratories performing STAT testing must hold a CLIA certificate appropriate to the complexity of tests performed: waived tests (simple tests like glucose meters require only a Certificate of Waiver); moderate complexity (most routine chemistry and hematology); or high complexity (most specialized panels). All non-waived laboratory testing — including most STAT panels — requires personnel with specific qualifications, documented quality control procedures, participation in proficiency testing programs, and biennial inspections by CMS or an approved accrediting organization (CAP, TJC, COLA). POC STAT devices deployed across a healthcare system still require CLIA oversight and must be included in the laboratory’s QC program, even if individual tests are CLIA-waived.
Conclusion
STAT laboratory tests are the backbone of emergency and critical care medicine, providing the rapid diagnostic information that guides some of the most consequential decisions in patient care — from ruling in or out a heart attack, to identifying septic shock, to determining whether a patient is bleeding and needs an emergency transfusion. The landscape of STAT testing continues to evolve: high-sensitivity troponin assays have compressed cardiac rule-out protocols from hours to minutes; procalcitonin has joined lactate as a consensus sepsis biomarker; and point-of-care testing has expanded the reach of STAT results to the bedside, the trauma bay, and even the ambulance.
For healthcare systems, clinical research organizations, pharmaceutical companies running biomarker trials, and medical device manufacturers validating diagnostic platforms, access to accredited laboratories with verified STAT capabilities is a critical operational need. ContractLaboratory.com connects organizations requiring medical and clinical laboratory testing with STAT-capable, CLIA-certified, and CAP- or Joint Commission-accredited laboratory partners. Submit a testing request or contact our team to find the right clinical laboratory for your STAT testing needs.