Tawnell D. Hobbs and Andrea Fuller:

Some of the wealthiest U.S. colleges are steering parents into no-limit federal loans to cover rising tuition, leaving many poor and middle-class families with debt they can’t repay.

Parents at Baylor University had the worst repayment rate for a type of federal loan called Parent Plus among private schools with at least a $1 billion endowment, according to a Wall Street Journal analysis of available Education Department data. Only about a quarter of Baylor parents paid down any of what they originally borrowed after two years.

Unlike undergraduate loans that have limits, there is no cap on what parents can borrow through the fast-growing Parent Plus program, no matter their income. Some parents wanting the best schools available for their children sign on the dotted line unaware how the debt can burden them into retirement.

Baylor increased its tuition sharply to transform itself from a regionally known Baptist college into a national brand that now has a $1.8 billion endowment. The central Texas school has added facilities, built a sports powerhouse and climbed college-ranking lists in a push to become a world-class research institution.

“They told me it was ‘good debt’—that it will pay itself off,” Ms. Massey said of family members who encouraged her to attend Baylor. “I honestly haven’t found anybody that cares about where I went to school.”