When Michelle Bisutti, a 41-year-old family practitioner in Columbus, Ohio, finished medical school in 2003, her student-loan debt amounted to roughly $250,000. Since then, it has ballooned to $555,000.

It is the result of her deferring loan payments while she completed her residency, default charges and relentlessly compounding interest rates. Among the charges: a single $53,870 fee for when her loan was turned over to a collection agency.

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