Today, dozens of manufacturers have restricted 340B pricing on their drugs when dispensed from contracted retail pharmacy sites. They often require covered entities to designate a single retail pharmacy for inclusion in its network and make 340B pricing contingent on submitting claims data using the drug-industry platform 340B ESP.

Several drugmakers have added other requirements, including retrospective time restrictions to resubmitting eligible claims for replenishment, leaving a confusing and complicated tangle of rules for covered entities. Worse, there is evidence that some manufacturers are not restoring 340B discounts even after entities follow all the rules.