Your are right regarding MEDICAID patients (indigent patients covered under the federal program administered by the states).
For patients covered under private Rx insurance (and some other groups) G-1 and Clindesses has to be listed in the groups formulary for reimbursement to occur without prior authorization. Even if listed, the products may be subject to a high co-pay. As it turns out today, most groups won't list G-1 or they require a very large co-pay ($30, $60, etc). What KV has planned to do to encourage the filling of G-1 Rx's, like they tried to do with Makena, is to offset the high co-pay with a voucher. For example, if the KV voucher is for $20 and the co-pay is $30 then the patient only has to pay $10.... however the 3rd party payer still has to pay the difference... KV does not eat the difference as with the Medicaid patient. The 3rd party payers don't like these voucher systems since they get stuck paying the difference.... usually what they do to offset the voucher is raise the co-pay very high. They did this with Makena with co-pays being as much as $120 and more, so that patient would have to pay at a level that they would refuse the branded Makena and choose the compounded version which had a small or no co-pay,