By the time they reach their reach their peak earning years (age 56 to 60), liberal arts majors make some $40,000 more than they did just out of school. While they make less than classmates with professional degrees through much of their careers, salaries for liberal arts majors peak at about $66,000 a year, some $2,000 more than those with professional degrees.
(Read more: A quarter of recent college graduates lack jobs)
To be sure, liberal arts majors still earn significantly less throughout their lives than math and science grads, who are pulling in about $87,000, on average, by their late 50s. Engineers end up on top of the salary scale, making peak salaries of $98,000.
A lot depends on the careers liberal arts majors end up pursuing: Those who go into the legal profession earned $127,000 a year at the peak, while those in service jobs topped out at $37,000.
While their salaries may catch up over time, liberal arts majors can expect to pound the pavement harder than the rest of their classmates throughout their careers. While the jobless rate falls from 5.2 percent for liberal arts majors just out of school to 3.5 percent when the reach 41- to 50-year-old, they never quite close the unemployment gap with professional graduates, whose rate drops from 4.2 to 3.1 percent among the same age groups.
(Read more: College graduates embrace nannying as career)
—By CNBC's John Schoen. Follow him on Twitter
@johnwschoen or email him.