Loading...

    Explore
    • Policy Monitoring
    • Live Policy Feed
    • Billing Codes
    • NPI Medicare & Medicaid
    • Healthcare Providers
    • Health Insurance Payers
    • States
    • Service Lines
    • Taxonomy Codes
    Lookup tools
    • Billing Code Lookup
    • CPT Modifier Lookup
    • Provider Taxonomy Code Lookup
    • Healthcare Provider & Facility Lookup
    • Health Insurance Payer Lookup
    • Payer Contact Directory

    Policy & Benchmark Tools

    • Prior Authorization Lookup
    • Coverage Criteria Lookup
    • Timely Filing Lookup
    • Billing Code Reimbursement Rates
    • Payer Comparison Dashboard
    • Facility Comparison Dashboard
    • All tools

    Company

    • About OpenPayer
    • Data Sources
    • Trek Health
    OpenPayerby Trek Health
    LinkedInYouTube

    © 2026 Trek Health. All rights reserved.

    OpenPayer is built and maintained by Trek Health.

    v1.0.28
    OpenPayerPolicy UpdatesImmunology/RheumatologyAlliance Health RETHYMIC Coverage & Prior Auth | O…
    Ask Trek AI about this page
    CurrentAlliance HealthPolicy Clinical Coverage Policy No:11B-9

    Thymus Tissue Implantation (RETHYMIC)

    Customize your policy alerts

    Sign up for Alliance Health Policy Clinical Coverage Policy No:11B-9 alerts

    Get alerted when Policy Clinical Coverage Policy No:11B-9 changes without checking for updates manually.

    Monitor payer policy activity

    Receive email alerts as soon as relevant payer policies are published or updated.

    North Carolina Medicaid clinical coverage policy for single-administration allogeneic processed thymus tissue (RETHYMIC) implantation for immune reconstitution in beneficiaries with congenital athymia, describing medical necessity criteria, exclusions, prior approval, billing and reimbursement guidance.

    Policy Summary
    PayerAlliance Health
    PolicyThymus Tissue Implantation (RETHYMIC)
    Policy CodePolicy Clinical Coverage Policy No:11B-9
    Change TypeNew policyreimbursement amendment
    Effective DateJun 1, 2023
    Last ReviewAug 15, 2023
    Next Review Date
    Key ActionObtain prior approval and submit the PA request with supporting records (letter of medical necessity, lab confirmation of congenital athymia, infection control documentation, and HLA matching when applicable) before performing Thymus Tissue Implantation.
    SourceLink

    OpenPayer is powered by Trek Health's payer performance platform. Trek continuously ingests, validates, and normalizes Transparency in Coverage data alongside payer policies and other commercial payer data to create a structured payer intelligence foundation. OpenPayer uses this foundation to deliver personalized search results, dynamically generated policy pages, and tailored policy monitoring based on each user's payers, specialties, billing codes, and areas of interest. The same intelligence powers broader payer performance workflows, including reimbursement benchmarking, contract evaluation, payer negotiations, and financial decision-making.

    POLICY UPDATE CHANGES

    Policy created for Thymus Tissue Implantation effective 06/01/2023.

    08/15/2023 amended Attachment A Section H to add reimbursement information for inpatient claims.

    1Allowed administrations per lifetime
    17Maximum beneficiary age for coverage
    50 cells/mm3 or 5%Naïve T-cell threshold for diagnosis

    Coverage Summary

    This is North Carolina Medicaid Clinical Coverage Policy No:11B-9 for Thymus Tissue Implantation (RETHYMIC). The policy effective date is 06/01/2023 and was last amended/reviewed on 08/15/2023. Coverage stance: covered with criteria for a single administration (once per lifetime) of allogeneic processed thymus tissue for immune reconstitution in beneficiaries with congenital athymia, subject to specified medical necessity and prior approval requirements.

    Thresholds and Quick Facts
    Allowed administrations per lifetime1
    Maximum beneficiary age for coverage17 years
    Naïve T-cell threshold for diagnosisfewer than 50 naïve T cells/mm3 (CD45RA+, CD62L+) OR <5% of total T cells naïve phenotype
    Age threshold17 years of age and younger

    Medical Necessity Criteria

    General Medical Necessity Criteria

    Medicaid shall cover procedures when medically necessary and the following general criteria are met:

    ALL of the following

    • The procedure, product, or service is individualized, specific, and consistent with symptoms or confirmed diagnosis of the illness or injury under treatment, and not in excess of the beneficiary's needs
    • The procedure, product, or service can be safely furnished, and no equally effective and more conservative or less costly treatment is available statewide
    • The procedure, product, or service is furnished in a manner not primarily intended for the convenience of the beneficiary, caretaker, or provider

    Specific Criteria Covered for Thymus Tissue Implantation (single administration)

    Medicaid shall cover a single administration of allogeneic processed thymus tissue for immune reconstitution in a beneficiary 17 years of age and younger when ALL of the following are met:

    ALL of the following

    Not Covered / Experimental

    Not Covered - General

    Medicaid shall not cover when any of the following apply:

    ANY of the following

    • Beneficiary does not meet the eligibility requirements listed in Section 2.0
    • Beneficiary does not meet the criteria listed in Section 3.0
    • The procedure, product, or service duplicates another provider's procedure, product, or service
    • The procedure, product, or service is experimental, investigational, or part of a clinical trial

    Not Covered - Specific

    Medicaid shall not cover the use of allogeneic processed thymus tissue for the following specific indications:

    Coding

    Prior Approval CPT code for PA entryCPT
    60699Unlisted procedure, nervous system (used in NCTracks when entering prior approval for Thymus Tissue Implantation)
    ICD-10-PCS Code(s) (Inpatient procedural coding)ICD-10
    XW020D8INTRODUCTION OF ENGINEERED ALLOGENEIC THYMUS TISSUE INTO MUSCLE, OPEN APPROACH, NEW TECHNOLOGY GROUP 8
    CPT/HCPCS unlisted procedure guidancemixed
    No codes listed

    Provider Actions & Billing Rules

    Prior Authorization

    Prior approval required

    Provider must obtain prior approval before rendering Thymus Tissue Implantation. Use CPT code 60699 in NCTracks when entering the prior approval request.

    • Enter PA using code 60699
    • Obtain PA before service
    Documentation Required

    Submit supporting medical records to Utilization Review Contractor

    Submit the prior approval request and all supporting health records to the DHHS Utilization Review Contractor. Required documents include a signed letter of medical necessity, lab results confirming congenital athymia, documentation of infection control measures, and HLA matching documentation when applicable.

    • Letter of medical necessity signed by attending physician
    • Lab results confirming congenital athymia (per Subsection 3.2.1)

    Background

    RETHYMIC (allogeneic processed thymus tissue) is a regenerative thymus tissue implantation therapy for immune reconstitution in children with congenital athymia, a condition in which a child is born without a thymus and typically experiences severe T-cell lymphopenia and early mortality.

    Indication: single administration for immune reconstitution in beneficiaries 17 years of age and younger with confirmed congenital athymia when specific criteria are met (including naïve T-cell thresholds, infection control capability, absence of prohibitive comorbidities, and HLA matching when applicable).

    Dosing principles: dosing is patient-customized and determined by the surface area of the RETHYMIC slices in relation to the beneficiary's body surface area.

    Definitions
    AllogeneicTransplantation of cells, tissues, or organs between genetically different individuals of the same species.
    Flow CytometryLaboratory technique that quantifies cell populations and characteristics such as naïve T-cell counts.
    HLA MatchingTesting to determine human leukocyte antigen compatibility between donor and recipient.
    EPSDT

    Revision History

    06/01/2023policy_created

    Policy created for Thymus Tissue Implantation (new policy established coverage and criteria).

    08/15/2023policy_amendedLatest

    Amended Attachment A Section H to add reimbursement information for inpatient claims (product invoiced and reimbursed at cost; inpatient reimbursement uses DRG methodology).

    Policy Summary
    PayerAlliance Health
    PolicyThymus Tissue Implantation (RETHYMIC)
    Policy CodePolicy Clinical Coverage Policy No:11B-9
    Change TypeNew policyreimbursement amendment
    Effective DateJun 1, 2023
    Last ReviewAug 15, 2023
    Next Review Date
    Key ActionObtain prior approval and submit the PA request with supporting records (letter of medical necessity, lab confirmation of congenital athymia, infection control documentation, and HLA matching when applicable) before performing Thymus Tissue Implantation.
    SourceLink
    On This Page
    Coverage SummaryMedical Necessity CriteriaNot Covered / ExperimentalCodingProvider Actions & Billing RulesBackgroundRevision History
    • Congenital athymia is confirmed via a circulating T-cell count on flow cytometry demonstrating fewer than 50 naïve T cells/mm3 (CD45RA+, CD62L+) in the peripheral blood or less than 5 percent of total T cells being naïve in phenotypeNaïve T-cell count: <50 cells/mm3 OR <5%
    • Documentation that infection control measures, consisting of immunoprophylaxis and withholding of immunizations, can reasonably be maintained until the development of thymic function is established
    • Absence of comorbidities, in the opinion of the treating clinician, that are reasonably likely to result in severe complications, including death from administration of allogeneic processed thymus tissue (examples: pre-existing renal impairment, or cytomegalovirus or Epstein-Barr virus infection)
    • HLA matching is required, performed and documented in a beneficiary who has received a prior hematopoietic cell transplantation (HCT) or a solid organ transplant

    ANY of the following

    • Immune reconstitution in a beneficiary with severe combined immunodeficiency (SCID)
    • Repeat administration in a beneficiary who has previously received allogeneic processed thymus tissue
  1. Documentation of infection control measures (immunoprophylaxis and withholding immunizations)
  2. HLA matching documentation when applicable (prior HCT or solid organ transplant)
  3. Billing Rule

    Single administration / Once per lifetime

    Thymus Tissue Implantation is authorized as a single administration only (once per lifetime). Repeat or continued administration is not authorized.

    • One administration per lifetime
    • Repeat administration is not covered
    Billing Rule

    Inpatient billing and product reimbursement

    Institutional inpatient claims (UB-04/837I) use DRG methodology for the inpatient stay and procedure; include the PA number on the claim. The product RETHYMIC should not be submitted on the inpatient claim — submit via invoice with the required PA number and it will be reimbursed at cost (no markup). Use ICD-10-PCS code XW020D8 for inpatient procedural coding where applicable.

    • Inpatient claims use DRG methodology; include PA number on claim
    • RETHYMIC invoiced separately with PA number and reimbursed at cost (not billed on UB-04)
    • ICD-10-PCS code: XW020D8
    Documentation Required

    EPSDT considerations for beneficiaries under 21

    EPSDT does not eliminate the prior approval requirement for beneficiaries under 21. Providers requesting exceptions under EPSDT must still document medical necessity per EPSDT criteria when requesting exceptions to policy limitations.

    • EPSDT does not waive the PA requirement
    • Document how the service meets EPSDT medical necessity when requesting exceptions
    Early and Periodic Screening, Diagnostic, and Treatment requirement mandating coverage of medically necessary services for Medicaid beneficiaries under 21 when criteria met.