Nearly 38 million working-age Americans have attended college without earning a degree, according to the National Student Clearinghouse. As the number of high school graduates declines, bringing these learners back has become a growing priority for colleges.

Today's "new majority" of students brings diverse life experiences, responsibilities and needs to campus, says new report. Supporting these students is essential for colleges that want to adapt.

Instead of the existing flat 1.4% tax rate, there is now a new multi-tiered rate of up to 8%, with larger endowments subject to the highest rate. The Joint Committee on Taxation estimates this endowment tax will bring in $761 million over 10 years.

Non-selective schools heavily reliant on international enrollment and already under financial stress could slide into "negative territory," according to Moody's Ratings.