Insulin provides essential treatment for millions of people living with diabetes but despite its low production cost, one in six Americans with diabetes ration their supply because of the cost. Medicare, federal health insurance for seniors, is about to institute a $35 per month cap on insulin for its beneficiaries, a few states have passed their own out-of-pocket caps, and states have sued the drug companies that currently produce insulin. But a handful of states, led by California, are considering providing an actual at-cost alternative. California has requested proposals from existing enterprises to produce generic insulin in the next few years, but in the long term, plans a government factory. If manufacturing a cheap generic insulin proves viable, a public marketplace for public pharmaceutical production might emerge.