Frequently Asked Questions (M00086, V22)

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MolDX General Questions

1. What is the purpose of the MolDX program?
To identify tests, determine coverage, and determine reimbursement.

2. How does this program help claim adjudication?
Once the required information is received and a DEX Z-Code™ identifier is assigned, Palmetto MolDX can determine coverage and payment without documentation review. This process removes the need for the provider to submit large amounts of additional information with every claim and expedites claim payment.

3. What laboratories will be affected?
All private, reference, and hospital laboratories that perform molecular diagnostic testing and submit claims to Medicare in JE, JF, JJ, JM, J15, J5, or J8 on forms CMS 1500 (Part B), UB04 (Part A) or electronic claims on a 5010-837P (Part B) or 837I (Part A) are affected by this program. (Please reference the specific jurisdiction MDT policy for effective dates.)

4. What molecular diagnostic assays/tests are included in MolDX?
Please visit the MolDX website for an up to date list of CPT codes that are within the MolDX scope of work. Submit questions about specific tests/assays not described in this chart to to

5. Is the MolDX Program national in scope?
The MolDX Program currently covers JE (American Samoa, CA, Guam, HI, NV, North Mariana Islands), JF (AK, AZ, ID, MT, ND, OR, SD, UT, WA, WY), JM (NC, SC, VA, WV), J15 (KY, OH), JJ (TN, GA, AL) J5 (IA, MO, KS, NE), and J8 (MI, IN). The role-out of JJ by Palmetto GBA began in early 2018. Labs that perform services for patients in those states have been notified to begin DEX Z-Code registration. Claims submitted after June 1, 2018, must have a Z-Code. 

6. How does a lab register a test? 
Review MolDX Molecular Test Registration and Claims Submission for instructions.

7. What is McKesson’s, now Change Healthcare, involvement in the MolDX program?
McKesson, now Change Healthcare, is the contracted technology provider for the MolDX program. MolDX will leverage the Diagnostics Exchange™ (DEX), the online test registry and technical assessment components of the MolDX program. DEX is a web-based service designed to identify tests and help establish transparency in the evidence-based coverage of them. This tool enables labs to confidentially share test information with MolDX online. Please visit

8. What information will be made available to the public?
MolDX information collected for the registry will only be available to those labs electing to submit a DEX Z-Code™ identifier application and is consistent with the public/private indications therein.

MolDX Registration (Z-Code applications)

1. Should the manufacturer or the performing lab register an FDA-approved, in vitro diagnostic test that utilizes a kit?
The manufacturer and the performing labs should submit an application. The MolDX team will review each submission for accuracy and assign each performing lab that reports the test without modifications the same code. The lab must submit an application in order to obtain a DEX Z-Code™ identifier for submission. Without the application information, MolDX cannot determine the kit is unmodified and the labs that intend to use the kit.

2. If multiple tests may be performed and billed within one assay, is the lab required to register each test within the assay?
A DEX Z-Code™ identifier application is required for a single assay that may involve multiple tests in order to produce a single result.

3. Is a unique identifier application required for an FDA-approved test?
Yes. The FDA approval process ensures only the clinical and analytical validity of the test. The FDA does not include clinical utility in their review, which is required to establish Medicare coverage.

4. After a test is granted a unique identifier, can a hospital bill their respective MAC directly for the test using the assigned DEX Z-Code™ identifier?
Yes. Effective March 1, 2017, hospitals must add the DEX Z-Code™ identifier in block 80 of the UB04 claim form or on line SV202-7 of the 837I electronic claim. 

5. Is a unique identifier required for tests billed with a NOC code?
Yes. Review MolDX Molecular Test Registration and Claims Submission.

6. Are labs expected to register tests sent to another lab to perform?
Both labs must register as an organization in DEX. The performing lab submits the test details to receive the Z-code. If you send your labs to a reference lab to be performed, you will need to request “sharing” in DEX in order to obtain access to the Z-code. The billing lab uses the Z-code of the performing lab. The two labs link up in DEX with a Sharing Request. Labs will only request Z-codes for labs that are performed in house. You are required to register your organization in the DEX Diagnostics Exchange if you plan to submit claims to jurisdictions that implement MolDX.

7. If a lab performs the same exact test from two different locations, operating under two different CLIA numbers, will the lab be required to submit both tests for unique identifiers?
If the test process is standardized and the same method is used to acquire the results in both locations, labs will only have to submit one application for the test. However, if there is a difference in the method, an application will be required from both locations.

8. If the kit used in an LDT is not FDA-approved, should the lab apply for a unique identifier for that kit? 

9. Are labs required to register tests that use a code in the MolDX code range and a code that is not listed in the MolDX range of codes?
Yes. Labs must register tests that include MolDX and non-MolDX range of codes in the test panel. MolDX will map only the test(s) in the MolDX range of codes. (i.e., EGFR by molecular methodology and ROS1 and ALK by IHC)

10. When a laboratory modifies an FDA approved kit, will MolDX require a new unique identifier?
Yes. If a lab modifies a registered test, the resulting test is considered an LDT and will require a separate application.

11.  Are hospital labs that file institutional claims and providers that file professional claims exempt from the requirement to obtain a unique identifier?
Providers submitting institutional claims are required to submit claims with DEX Z-Codes. Physicians submitting professional claims (-PC or -26) are not required to use Dex Z-Codes. 

Technical Assessment (TA)

Please review the TA section of the MolDX website for specific information on the TA submission process.

1. Who will perform the technical assessments (TA)?
Subject matter experts (SME) from academia and industry will assess the scientific literature. The MolDX team will perform the assessment for all other components.

2. Will there be an opportunity for a laboratory to comment on a TA report before it is finalized?
Yes. Questions/concerns that surface during the TA will be communicated with the test developer.

3. Will laboratories and/or manufacturers be allowed to resubmit a coverage request after they have received a non-coverage determination?
Yes. If substantive new information, not included in the initial submission, becomes available, a new request may be submitted 6 months after the initial non-coverage determination was issued.

4. Can a lab provide services prior to the TA approval date in anticipation of a favorable determination and then submit the claims after the approval?
To avoid overpayment requests, labs should freeze services until coverage is approved and appropriate billing and coding guidelines are published.

5. If a lab plans to submit a test for FDA approval, can the test be submitted for a TA first?
If the test is currently in the FDA process, please hold the TA request until the FDA has completed its determination. However, if you have not submitted the test to the FDA, you may request a TA. The FDA submission should be done prior to TA request. Once you receive an FDA determination, you may submit a TA request.

6. Will a completed TA be made available on the MolDX website?
MolDX may publish proprietary information from a TA on the MolDX website.

7. How should a laboratory designate proprietary information on the TA submission?
MolDX will consider any information that is not publicly available to be proprietary information.

8. How will MolDX determine reimbursement for a test?
Reimbursement is based on accurate submitted codes regardless of the cost of the platform used. For tests that are reported with an NOC code, pricing will be determined based on the information collected in the TA. Each test will be assessed on an individual basis and priced according to the most appropriate method. the MolDX Team will review the pricing method with the individual lab upon completion of the TA.

9. What resources are available to help me determine the best CPT code to bill my new test?     
All test applications are reviewed for correct CPT mapping by the MolDX Team. After a TA is complete, the Team will notify the test provider with the final coding, billing, coverage, and if applicable allowed fee for the test.

Billing and Coding

1. What are the effective dates of the Z-codes?
After DEX assigns a Z-code to a lab for a specific test, the MolDX team will review the test application and will assign a CPT code to the test.  The Z-code can be submitted on claims once it is mapped by MolDX and entered into the master edit file for claims adjudication.

2. What action should a lab take if they believe they may have incorrectly billed for a MolDX service?
If you believe your practice has made a MolDX billing/coding error, you may take the following corrective actions:

  • Complete a Self-Audit
    • Identify incorrect submissions
    • Prevent further claim submission errors
  • Consider Self-Disclosure Protocol
    • Self-disclosure guidelines available on the OIG website


1. Will ABN’s be valid with the unique identifier?
The DEX Z-Code™ identifier is only additional information, not a billing code.

2. Will MolDX pay test services provided prior to the TA approval date?
All new test services will be denied as noncovered until the test completes the TA process and reasonable and necessary criteria is established. Claims submission for tests in the TA process should be suspended until a final coverage determination is made.

3. Is the reimbursement for a flow cytometry affected by MolDX?
Palmetto GBA has an active LCD for Flow Cytometry and will continue to administer coverage as published in that policy the same as any other active policy.