MolDX Z-Codes and Inpatient Claims

on Tuesday, 28 November 2017. All News Items | Billing

I Stand Corrected

Last week’s Wednesday@One newsletter contained an article about the new laboratory date of service policy and the molecular diagnostic services (MolDX) program.  In that article, I made this statement:

“Since CPT/HCPCS codes are not reported and separately reimbursed (on inpatient claims), the Z-codes are not required on inpatient claims.”

I thought about this before I wrote it – individual HCPCS codes are not reported or separately reimbursed on Medicare hospital inpatient claims (type of bill 11x). The inpatient stay is paid a composite payment for all inpatient services provided based on the MS-DRG assignment determined by the ICD-10 diagnosis and procedure codes reported. Since the purpose of the MolDX program is to determine coverage, coding, and pricing for molecular diagnostic tests and other molecular pathology services which are not relevant to inpatient claims and since the MolDX manual instructions state, “When (a test-specific identifier – a DEX Z-Code is) reported in conjunction with the appropriate CPT/HCPCS code, …” which also does not seem to apply to inpatient claims, I felt confident with my statement about Z-codes not being required on inpatient claims.  It seems absolutely unnecessary and makes no sense that they should be reported.

However, I could not find this definitively spelled out on the MolDX website, so I decided to submit a question to the MolDX email address. I did not receive the answers in time to make a correction to last week’s article prior to publication. Below are my questions and the answers I received from MolDX team.

Q: Since individual CPT/HCPCS codes are not submitted on inpatient claims, are DEX Z-codes required to be reported on inpatient claims when molecular pathology tests are performed on an inpatient?

A: Yes. You will need to register with DEX and obtain the Z-code for all Molecular tests performed at your location.

Q: Could you please clarify further as to where the Z-codes would be reported on the inpatient claim since individual HCPCS codes are not reported on inpatient claims?

A: DEX Z-Code identifiers need to be added in block 80 of the UB04 claim form or on line SV202-7 of the 8371 electronic claim.

Well – there you go. Even though it still makes no sense to me, these answers contradict the statement I made in last week’s article. I have removed the ‘erroneous’ statement from the article on our website. Unless there is ever definitive guidance to the contrary, it seems that the Z-codes are indeed required on inpatient claims.

That will teach me to deduce Medicare rules based on what makes sense.

Article by Debbie Rubio

Debbie Rubio, BS, MT (ASCP), is the Manager of Regulatory Affairs and Compliance at Medical Management Plus, Inc.  Debbie has over twenty-seven years of experience in healthcare including nine years as the Clinical Compliance Coordinator at a large multi-facility health system.  In her current position, Debbie monitors, interprets and communicates current and upcoming regulatory and compliance issues as they relate to specific entities concerning Medicare and other payers.  You may contact Debbie at This email address is being protected from spambots. You need JavaScript enabled to view it..

This material was compiled to share information.  MMP, Inc. is not offering legal advice.  Every reasonable effort has been taken to ensure the information is accurate and useful.

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