As reported from Chessnews.org:
Should we be alarmed about losing 3209 members in only three months? March 1 to June 1 is historically a seasonally weak period for USCF membership numbers, as the following records show:
USCF membership losses, March 1-June 1
2003 Lost 4751 members
2004 Lost 3906 members
2005 Lost 4130 members
2006 Lost 3268 members
2007 Lost 2349 members
2008 Lost 2422 members
2009 Lost 3209 members
So the loss this year was greater than 2007 or 2008, but not enormously so, and smaller than each of the previous four years. And there is good reason to believe the main cause is cutbacks in school chess programs, as adult membership during this period has declined only by 97 members.
The year 2006-2007 was a fairly good one for USCF. However, it is false that USCF showed losses in every other year since 1995. In each of 2003-2004 and 2004-2005, USCF had a surplus of over $200,000, and that's without including the building sale and land gift recorded in 2004-2005, which if included would have dramatically increased that surplus.