Some dream jobs lead to nightmare finances.

It's largely thanks to student loans and the exorbitant debt it can take to get an "MD" or "JD" after your name, and the type of loan that accompanies those degrees — graduate PLUS loans — which allow borrowers to cover up to the full cost of attendance for a program without any caps. 

The number of Americans who owe at least $1 million in federal student loans has been growing over the past few years. As recently as 2013, it was only 14; by 2018, that figure ballooned to 101 people owing at least $1 million, the Education Department confirmed to The Wall Street Journal four years ago. 

It's something that often gets overlooked when considering broad student-loan forgiveness. Many Republican lawmakers have slammed the idea of canceling student debt for all federal borrowers because the highest earners, like doctors and lawyers, would benefit. In an apparent attempt to counter that criticism, Biden is considering$10,000 in relief for borrowers making under $150,000 a year, The Washington Post reported — likely under the notion that an income cap would ensure relief went to those in most need.

Here are three reasons that may explain why some typically high-earning graduates can't clear their debt. 

High interest rates

Interest capitalization is often to blame for student-debt balances that continue to surge. It happens when accrued interest is added to the original loan balance, and future interest grows based on that higher principal amount.

Steve Pederzani, 37, is all too familiar with that. As a licensed attorney without a steady job, he took out grad PLUS loans to finance his education — but medical complications with his fiancée pushed back his bar-exam timeline by a few years, which made his job search more difficult. During that time, interest continued to build on his debt, and the principal ballooned to $347,000.

"There are a substantial number of people like me that are being forgotten," Pederzani previously told Insider. "We're being left behind."

Long-term repayment plans 

Kathleen LaRose, a podiatrist in North Carolina, graduated from medical school in 1987, having borrowed $277,000 in federal loans. Twenty-eight years later, she owes $895,512.97 in student debt, which Insider verified — all while on an income-based repayment plan that should have granted her loan forgiveness three years ago.

Uncapped graduate-school borrowing 

Mike Meru, a Utah orthodontist who made headlines in 2018 for having more than $1 million in debt, has most of his debt through grad PLUS loans. 

He originally borrowed $601,506, a number that nearly doubled by May of 2018, according to The Wall Street Journal. 

There are no limits on loans borrowers can take out through grad PLUS, loans exclusively available to graduate and professional students.