At a time of grim prospects for Americans without a college degree, nursing can look like a rare chance not just for a job but a real career.

Or at least it did.

There were more than 2.6 million registered nurses employed in the U.S. in 2012, according to the Labor Department, plus another 718,000 licensed practical and vocational nurses and tens of thousands of nurse practitioners and other advanced specialists. RNs made nearly $68,000 per year on average in 2012, and the Labor Department expects employment to grow by more than a quarter between 2010 and 2020.

Nursing’s appeal isn’t just its size or growth prospects but also its low barriers to entry: Registered nurses typically needed only an associate’s degree, and licensed practical nurses don’t need a college degree at all. And unlike many jobs available to less-educated workers, nursing offers a clear upward path: LPNs can become RNs. RNs can become nurse anesthetists, nurse midwives or nurse practitioners, who can perform many tasks traditionally performed by doctors. Hospitals often provided on-the-job training or tuition reimbursement to help lower-level nurses advance.