 The Department of Veterans Affairs, which is allowed to negotiate drug prices and establish a formulary, has been estimated to pay between 40% and 58% less for drugs, on average, than Part D. On the other hand, the VA only covers about half the brands that a typical Part D plan covers.Part of the issue is that Medicare does not pay for Part D drugs, and so has no actual leverage.Part D drug providers are using the private insurer leverage, which is generally a larger block of consumers than the 40 million or so actually using Medicare parts A and B for medical care.