Maybe all that student debt is worth it, after all.

College graduates earn $1 million more than high school graduates over their lifetime, and the income gap between the highest-paid college majors and the lowest-paid is more than $3 million dollars. This is all according to a study released Thursday by the Georgetown University Center on Education and the Workforce. The study analyzed wages for 137 college majors to discover the economic benefit of earning an advanced degree by undergraduate major.

“Not all bachelor’s degrees are created equal,” the report concluded. Among the 15 groups of college majors studied, architecture and engineering majors are paid the most and education majors are paid the least. Graduates with degrees in top-paying college majors earn $3.4 million more than those with the lowest-paying majors over a lifetime. Not surprisingly, STEM (science, technology, engineering, and mathematics) and health and business majors are the highest paid, leading to average annual wages of $37,000 or more at the entry level and an average of $65,000.

Others don’t fare as well, however. The 10 majors with the lowest median earnings include childhood education (with an annual median salary over their lifetime of $39,000 a year), human services and community organization ($41,000 a year), studio arts, social work, teacher education, and visual and performing arts ($42,000 a year), theology and religious vocations, and elementary education ($43,000 a year), drama and theater arts and family and community service ($45,000 a year).

Among college graduates with the same majors, earnings vary by state. Business is the most common major, accounting for 26% of college graduates. But business majors’ earnings vary. In California, they earn a median of $70,000 annually over their lifetime, but in Illinois and New York, they earn $67,000, and they earn $65,000 a year in Texas and $54,000 a year in Florida. “People are always shocked by how little money people make and, even for college graduates, that’s not bad,” says Anthony P. Carnevale, the center director and lead author of the report.

Student debt is still a heavy burden for the average college graduate. As of May 2015, the average student loan amount was $32,956 per borrower, and it remains the largest source of household indebtedness next to mortgages, according to Federal Reserve and U.S. Census data crunched by personal finance site NerdWallet.com. College graduates were carrying a total of $1.3 trillion in student loans as of December 2014, up $912 billion from five years earlier, Federal Reserve data found.

Read: The states with the most openings for college graduates