Key Takeaways
- Reflex testing, standing orders and add-on tests are distinct ordering arrangements, and the scope of the original order determines how far testing may proceed without additional authorization.
- Medicare treats certain reflex tests as implicit in the original order, but testing outside that order ordinarily requires separate authorization from the treating practitioner.
- Standing orders must be specific enough to show who authorized the testing, what it covers and when it remains in effect; blanket protocols do not qualify.
- Payor coverage rules may require pathologist review before additional stains are performed, so laboratory systems should preserve that decision point rather than automate past it.
Laboratories frequently perform additional testing based on the results of an initial test. A positive screening result may trigger confirmatory testing; a positive culture may require organism identification; or a pathologist may order additional stains after examining a tissue specimen. These workflows can improve diagnostic efficiency and reduce the need for repeated physician orders.
Ubiquitous as they may seem, standing orders, reflex testing and add-on tests still depend on the scope of the original order, applicable payor rules and medical necessity. Those factors determine how far a sequential testing pathway may proceed before additional authorization is required.
Five questions help define those boundaries:
1. What is the difference between a standing order, reflex testing and an add-on test?
Although sometimes used interchangeably, these terms describe different ordering arrangements.
A standing order authorizes specified laboratory testing over a defined course of treatment or period. This is common when a patient requires recurring laboratory monitoring at established intervals. The order generally remains effective until it expires, is modified or is discontinued.
Reflex testing involves additional testing triggered by the result of an initial test. A positive red blood cell antibody screen, for example, may trigger antibody identification. The follow-up testing is part of the diagnostic process initiated by the original order.
An add-on test is additional testing requested or determined to be necessary after an initial order was placed. Unlike reflex testing that is implicit in the original order, an add-on test may require a separate order from the treating practitioner.
These distinctions have practical consequences. Medicare’s 2026 National Correct Coding Initiative (NCCI) Policy Manual recognizes certain reflex tests as implicit in the physician’s original order but distinguishes them from other additional tests that require separate authorization.
2. When can a laboratory perform reflex testing without obtaining another order?
Medicare recognizes that some initial test results have limited clinical value without additional testing. A positive culture that requires organism identification and a positive red blood cell antibody screen that requires antibody identification are familiar examples. Medicare considers this type of reflex testing implicit in the original physician order. The additional testing may be separately reportable when applicable coding and coverage requirements are met. But the scope of the original order still sets the boundary.
The NCCI Policy Manual distinguishes these established reflex tests from testing that requires a separate authorization because the additional analysis falls outside the original order. An order to identify a monoclonal protein band does not automatically authorize additional testing to determine the type of monoclonal protein. That testing ordinarily requires authorization from the treating physician.
For a laboratory building a reflex protocol, knowing when the original order ends is an important compliance question. The workflow should identify the testing covered by the original order and the point at which additional authorization is required.
3. Can a standing order authorize reflex testing?
Yes, a standing order can authorize reflex testing when it is sufficiently specific to establish what the practitioner authorized.
Standing orders are commonly used when patients require recurring laboratory testing during an extended course of treatment. The Department of Health and Human Services Office of Inspector General has long recognized their use while cautioning laboratories to monitor their continuing validity.
A usable standing order should show who authorized it, what testing it covers, and the clinical circumstances in which it remains in effect.
A standing order should identify the recurring tests and the clinical circumstances in which they are authorized. That is different from a blanket protocol under which a laboratory performs the same testing for every patient. Medicare does not categorically require a signed requisition for clinical diagnostic laboratory tests, but the medical record still must show the treating practitioner’s intent to order the services and support the medical necessity of the testing for that patient. State law and individual payor requirements may impose additional conditions.
4. How can payor coverage rules affect reflex testing?
Gastrointestinal pathology illustrates how payor coverage rules can add a clinical decision point to an otherwise established reflex protocol.
Some Medicare contractors and commercial payors require pathologists to review the routine hematoxylin and eosin (H&E) slide before determining whether additional special stains or immunohistochemistry (IHC) are medically necessary.
A laboratory may have a clinically reasonable protocol that contemplates an H. pylori stain or another special stain based on the specimen and clinical history. Some coverage policies insert another step into that protocol: The pathologist must first review the H&E stain and decide whether additional testing is necessary.
Medicare LCD L35986 identifies reflex templates and pre-orders for additional stains before H&E review as practices that may produce medically unnecessary testing. The LCD generally requires the pathologist to review the H&E slide before ordering special stains or IHC, subject to recognized clinical exceptions.
A laboratory’s reflex protocol therefore should identify which testing may proceed automatically and which testing requires pathologist review first. Payor sequencing requirements remain part of the workflow even when the laboratory has a standing order or established testing protocol.
Another important question is who may authorize additional testing once pathologist review occurs. Medicare recognizes an exception for certain surgical pathology and cytopathology services that allows a qualifying pathologist to perform additional testing not specifically requested by the treating practitioner when the testing is necessary to reach a complete and accurate diagnosis, and the other requirements of the exception are met.
The two rules are complementary: A pathologist may have authority to order an additional stain after examining a specimen, and a payor may prohibit a laboratory from performing a stain automatically before the pathologist has done so. The laboratory information system therefore needs to preserve that decision point rather than automate past it.
5. What should laboratories review in their reflex testing protocols?
Laboratories should evaluate their reflex testing protocols from a clinical and reimbursement perspective. A protocol that is clinically appropriate also must account for applicable ordering and coverage requirements.
A useful review should ask whether the workflow is based on ordering and coverage rules in addition to the laboratory’s testing sequence. In particular:
- Does the initial order encompass additional testing, or is separate authorization required?
- What finding triggers the next test, and does someone need to review that finding before testing proceeds?
- Do applicable coverage policies impose a different trigger or sequencing requirement?
- Can the laboratory reconstruct from its records why the additional test was performed and, when required, who authorized it?
Laboratories should also periodically review their reflex testing protocols against changes in clinical practice, payor policies and utilization patterns.
The Readout
Standing orders and reflex testing are valuable because they allow laboratories to move efficiently from an initial test to the information needed for diagnosis. That efficiency depends on knowing what the original order authorizes and when another decision must occur.
At each step in a reflex algorithm, the laboratory should be able to identify the authority for the test and any clinical decision that must occur before testing proceeds.
A reflex algorithm should be both a technical pathway and an ordering pathway. The laboratory information system may know exactly what comes next, but the ordering pathway should determine whether the laboratory can proceed.
The Lab Protocol is for informational and educational purposes only and does not constitute legal, regulatory or compliance advice. Readers should consult qualified counsel regarding their specific circumstances.