Benefit and Prior Authorization Information for Rethymic

Date: August 3, 2026

Attention: All Providers

Effective date: July 1, 2026

Call to action: Texas Children’s Health Plan (TCHP) would like to inform providers that effective for dates of service on or after July 1, 2026, allogeneic processed thymus tissue-agdc (Rethymic) is a benefit of Texas Medicaid when it is submitted on a claim with procedure code J3590. Prior authorization will be required beginning September 1, 2026.

Allogeneic processed thymus tissue-agdc (Rethymic) is indicated for immune reconstruction in pediatric patients with congenital athymia.

Allogeneic processed thymus-agdc (Rethymic) is limited to one surgical procedure per lifetime.

Prior Authorization Requirements

Providers must submit prior authorization requests for allogeneic processed thymus tissue-agdc (Rethymic) on a Special Medical Prior Authorization (SMPA) Request Form.

The Texas Medicaid & Healthcare Partnership (TMHP) may approve prior authorization for allogeneic processed thymus tissue-agdc (Rethymic) for patients who meet the following requirements:

• The patient is 18 years of age or younger.
• The patient has a diagnosis of congenital athymia that is confirmed by flow cytometry (diagnosis code D821).
• Severe combined immunodeficiency (SCID) has been conclusively ruled out.
• An anti-human leukocyte antigen (HLA) antibody test was conducted before the start of treatment. If the patient tests positive for anti-HLA antibodies, they must receive allogeneic processed thymus tissue-agdc (Rethymic) from a donor who does not express HLA alleles.
• The prescriber must attest that the benefits and risks of treatment have been evaluated for patients with preexisting cytomegalovirus (CMV) infection or renal impairment.
• The patient has not previously received thymus tissue transplantation.

Required Monitoring Parameters

After allogeneic processed thymus tissue-agdc (Rethymic) implantation, providers must monitor the patient for the following:

• The risk of developing graft-versus-host disease (GVHD)
• The possibility of developing autoimmune or lymphoproliferative disorders, which is monitored through complete blood counts (CBC) with differential, liver enzymes, serum creatinine, urinalysis, and thyroid function
• Renal impairment or failure
• The occurrence of an infectious disease, as these may develop because allogeneic processed thymus tissue-agdc (Rethymic) is derived from human tissue

Next step for providers: Providers should share this information with their staff.

If you have any questions, please email Provider Relations at providerrelations@texaschildrens.org.

For access to all provider alerts: www.texaschildrenshealthplan.org/provideralerts