Medicare Lab Test Order and Signature Requirements for Genetic Testing
Short answer: Medicare requires that the treating provider order every diagnostic lab test, and tests ordered by anyone else are not reasonable and necessary. A valid order can be a signed order, an unsigned order backed by an authenticated record, or an authenticated record alone. The claim-submitting entity must keep the order documentation.
Why do lab test orders matter for genetic testing claims?
Many medical necessity problems on genetic testing claims start before the specimen reaches the lab. If the order is missing, cannot be tied to a treating provider, or is not supported by the clinic's own record, a reviewer has little to work with, no matter how well the lab billed the claim. CMS keeps a dedicated page, Lab Test Order Requirements, and a Medicare Learning Network fact sheet, MLN909221, on exactly this topic. The fact sheet is dated May 2026 and states that it contains no substantive content updates, so the rules below are settled policy rather than news. They are worth revisiting because contractors reviewing genetic test claims lean on them.
The regulatory anchor is 42 CFR 410.32, which sets out the conditions under which diagnostic tests are reasonable and necessary. CMS also points to Chapter 6, section 6.9.1 of the Medicare Program Integrity Manual for order requirements, and to Chapter 15, section 80.6 of the Medicare Benefit Policy Manual for how orders are delivered. For related reading on what reviewers look for, see our guide to genetic testing denials.
Who is allowed to order a Medicare lab test?
CMS is direct on this point. The MLN fact sheet tells providers: "You, the treating provider, must be the one to order all diagnostic lab tests." The CMS order requirements page defines the ordering provider as the physician, practitioner, or non-physician practitioner who is treating the patient, and states that tests not ordered for treating the patient are not reasonable and necessary.
For genetic labs this has a practical consequence. A requisition that arrives from a marketing contact, a telehealth intermediary with no treating relationship, or a standing arrangement that never involved a clinician who is managing the patient does not satisfy the rule, however complete the paperwork looks. Treating the ordering provider as a verified, identifiable person rather than a field on a form is the first control a lab should build. For the coverage side of the same question, our overview of Medicare coverage for genetic testing covers how necessity is judged once the order is valid.
What must a valid order contain?
The CMS page lists the documentation that must support the billed service. There must be documentation of the order itself, including information that allows CMS to find and contact the ordering provider. The lab must have the diagnostic or other medical information that was given with the order, including any ICD-10-CM code or narrative description. And medical necessity must be documented in the patient's medical record when the service is ordered.
CMS accepts three forms of support for a diagnostic lab order, shown below. The first is a signed order or signed prescription that lists the specific test. The second is an unsigned order or lab prescription that lists specific tests, together with an authenticated medical record showing the provider's intent to order. The third is an authenticated medical record alone that supports the ordering provider's intent to order specific tests.
The fact sheet adds that the medical record should show the order, including any standing order or protocol, or the intent to order. For standing orders or protocols, the fact sheet says to include a copy with the documentation and keep it available for claim review. That detail is easy to miss in high-volume programs where one protocol drives many orders.
Does a Medicare lab order need a signature?
This is the point most often misunderstood, and the CMS wording needs careful reading. The CMS order requirements page states that signatures are not required for orders for clinical diagnostic tests paid under the clinical laboratory fee schedule or the physician fee schedule, or for physician pathology services. The same page still lists a signed order as one of the acceptable forms, and the MLN fact sheet recommends that physicians sign all diagnostic service orders to avoid potential denials.
The fact sheet explains why signing is the safer habit: unsigned orders or requisitions alone do not show intent. If the order is unsigned, the treating provider must sign either the order or the supporting progress note, so that the record itself shows the decision to test. Signature and date stamps are not allowed, with a few exceptions, and the fact sheet says stamps are allowed only when a provider with a physical disability proves to the Medicare Administrative Contractor that they cannot sign.
The cure options are narrow. If a supporting progress note is missing a signature, the ordering physician can submit an attestation statement in response to the review contractor. An illegible signature can be supported by an attestation statement or a signature log. What an attestation cannot do, according to the fact sheet, is rescue an unsigned order or requisition.
How can orders be delivered to the lab?
CMS describes three delivery routes. A written, signed document can be hand-delivered, mailed, or faxed to the testing facility. A phone call from the provider or the provider's office to the testing facility also works, but both sides must document the call in the patient's record, and the provider must document intent to test, and no signed order is required. An email from the provider or office to the testing facility is also accepted.
For labs that take telephone or email orders, the control point is documentation on your own side. If your accessioning team records the call or email, preserve it in a form that can be produced during review, and make sure the clinic side is prompted to document intent in its record. The CMS page does not address standing orders or reflex testing in detail, so labs that run reflex pathways should keep the protocol itself on file and confirm requirements with their contractor.
What must the claim-submitting entity keep?
The fact sheet separates two roles. The treating provider orders tests and documents medical necessity and intent. The entity submitting the claim keeps the supporting documentation. Specifically, that entity must keep the order for the billed service including the information needed to find and contact the ordering provider, records showing that the order was processed and the claim submitted accurately, and the diagnostic or other medical information sent to the lab, including the ICD-10-CM code or narrative description.
The fact sheet does not state a retention period on the page itself. It refers readers to 42 CFR 424.516(f) on maintaining and providing access to documentation, so labs should confirm their retention schedule against that regulation and their contractor's guidance rather than relying on an informal rule of thumb. The fact sheet also does not discuss the Advance Beneficiary Notice, so ABN questions need to be answered from other CMS sources.
Why does this matter more for next-generation sequencing claims?
Review contractors have targeted sequencing claims specifically. A Recovery Audit Contractor approved issue, number 0205, covers next generation sequencing medical necessity and documentation requirements. It was posted on May 11, 2021, applies to laboratories, covers all A/B MAC jurisdictions, and names CPT/PLA codes 0111U, 0022U, and 0037U. Auditors check whether documented indications match the national coverage determination in Chapter 1, Part 2, section 90.2 of the NCD Manual, which covers NGS as a diagnostic laboratory test when performed in a CLIA-certified laboratory and ordered by a treating physician.
The phrase "ordered by a treating physician" appears in the rationale, which links the order rules in this article directly to a live audit issue. Our explainer on NCD 90.2 and NGS coverage for cancer testing covers the clinical criteria, and the order rules here decide whether a lab can prove them. Duplicate-order problems add another layer, covered in our piece on duplicate lab test denials and modifier 91.
What should labs do this quarter?
Four steps fit most programs. First, audit a sample of recent genetic test claims and confirm that each file contains an identifiable treating provider, a documented order or authenticated record of intent, and the diagnostic information that came with it. Second, set a rule for unsigned requisitions: either collect a signed order, or require the clinic's authenticated note that shows intent, because an attestation will not fix an unsigned requisition. Third, review how telephone and email orders are logged. Fourth, check that any standing order or protocol behind a test menu is on file and available for review.
Workflows that check coverage and documentation criteria before an order is finalized prevent most of these gaps at the source. To see how that works in practice, visit ScreenMyGene.
Frequently asked questions
Who can order a diagnostic lab test for a Medicare patient?
The treating provider, meaning the physician, practitioner, or non-physician practitioner who is treating the patient. CMS states that tests not ordered for the treating patient are not reasonable and necessary, so a requisition from anyone without a treating relationship puts the claim at risk.
Does Medicare require a signed order for lab tests?
CMS says signatures are not required for orders of tests paid under the clinical laboratory or physician fee schedules, but recommends physicians sign all diagnostic orders to avoid denials. Unsigned requisitions alone do not show intent, so an authenticated record supporting the order is needed.
Can a phone call or email count as a lab order?
Yes. CMS accepts orders by phone or email to the testing facility, in addition to signed written orders that are hand-delivered, mailed, or faxed. For phone orders, both sides must document the call and the provider must document intent to test.
Can an attestation fix an unsigned lab requisition?
No. The MLN fact sheet says attestation statements can support a missing signature on a progress note or an illegible signature, but attestations are not accepted for unsigned orders or requisitions. The order or the supporting note needs a valid signature.
What documentation must the lab keep?
The entity submitting the claim must keep the order for the billed service with the ordering provider's contact information, records showing correct order processing and claim submission, and the diagnostic information received, including the ICD-10-CM code or narrative description.
This article is educational and intended for laboratory and revenue cycle professionals. It is not legal, coding, or reimbursement advice, and it does not replace CMS or contractor documents. Verify all policies against current CMS and contractor publications before billing.
Sources: CMS, Lab Test Order Requirements (cms.gov/lab-test-order-requirements); CMS, MLN909221, Complying With Documentation Requirements for Lab Services, May 2026; CMS Recovery Audit Program, Approved Issue 0205, Next Generation Sequencing Medical Necessity and Documentation Requirements, posted May 11, 2021; 42 CFR 410.32; 42 CFR 424.516(f); Medicare Program Integrity Manual, Ch. 6, Sec. 6.9.1; Medicare Benefit Policy Manual, Ch. 15, Sec. 80.6; Medicare NCD Manual, Ch. 1, Part 2, Sec. 90.2.