
Medicare does cover Revatio, which is the same drug (sildenafil) as Viagra, but comes in different doses and is used to treat pulmonary arterial hypertension. To prevent abuse of this allowance, there are supposed to be auditors verifying that the patients actually have a diagnosis of PAH.
Interestingly, Hurricane Katrina was ultimately responsible for the loss of the Viagra coverage. Congress voted in 2005 to discontinue covering Viagra, and use that money to fund medical care and unemployment benefits for hurricane victims. However, despite the restrictions put in place, it came to light earlier this year that there had been a little slip up between 2007 and 2008, when Medicare accidentally paid out $3.1 million for Viagra and other ED drugs. Medicare administrators blamed it on a software error.