Under a relatively new “Buy Direct” program, you can purchase treasury securities with a toll-free phone call (800-943-6864) or at the Bureau of Public Debt Web site (www.publicdebt.treas.gov). Your investment will be deducted from a designated bank account so you don’t have to bother mailing in forms or checks. With the Buy Direct program you pay no fees, other than a $25 annual charge if your account exceeds $100,000. The minimum purchase is $1,000; not long ago, minimums were $10,000 for short-term treasury bills and $5,000 for intermediate-term treasury notes.