42 U.S.C. 247d-6b
From Conservapedia
42 U.S.C. § 247d-6b creates the "Strategic national stockpile and security countermeasure procurements," conferring authority on the Secretary of HHS to manage the Strategic National Stockpile.
More than 60 million doses of hydroxychloroquine - perhaps as much as 100 million doses -- are stored in the Strategic National Stockpile but withheld from the public amid the coronavirus pandemic.