Viral tropism tests are reimbursable through Medicaid fee-for-service using procedure code 87999 for Medicaid managed care enrollees. For Family Health Plus enrollees, these tests must be billed to the enrollee's health plan. Viral tropism testing identifies patients who are likely to respond to the new HIV entry inhibitor drug, Selzentry. Currently, one testing method (Trofile assay) is eligible for coverage.