Hi! You generally can't bill secondary Medicaid up to your cost-based rate if the primary insurance results in a $0 pt responsibility due to a contractual adjustment. For an FQHC, reimbursement is governed by payer hierarchy and COB rules- not an office's internal cost or PPS rate when a primary commercial plan is involved. Medicaid is always the payer of last resort, so they will not make additional payment up to the FQHC cost-based or PPS rate when no pt liability exists after the primary claim is adjudicated. Hope this helps!