The place where I keep my emergency fund is in U.S. Treasury I-Series savings bonds. Is there any reason why I wouldn't want to keep the emergency fund there? Is there a dynamic that I am not considering? Dave, Denver, CO

I'm a 36-year-old single professional in the DFW metroplex that tries to think long-term in my financial planning. I put 12 percent of my around $100,000 salary into my 401(k) with company match. Currently, the retirement fund is valued at about $100,000. I owe about $12,000 on my student loans (4.25 percent fixed interest, originally $80,000) and I have about 27 percent equity in my $180,000 town home. I recently refinanced my home at 4.125 percent for 15 years. My credit card debt is maybe $1,000. After surviving a layoff well (due to a generous severance in the Great Recession), I was scared straight once I started working again. I now have about $15,000 in an emergency fund and next year's bonus will go to this, too. So I have three questions: 1) Do I need 6 months of bills or 6 months of salary after tax? 2) Should I park this in savings? Or is there a better financial instrument? 3) Is the emergency fund a higher priority than nuking the graduate school debt? I appreciate your guidance. Keith, Plano, TX