18. Diagnostic medical sonographers



They use special imaging equipment that directs sound waves into a patient’s body to assess and diagnose various medical conditions.

Median annual wage (2015): $68,970

Education required: Associate’s degree

Projected job openings (through 2024): 27,500

Work experience: None

On-the-job training: None

17. Postmasters and mail superintendents


Paul De Los Reyes/Flickr

They plan, direct, or coordinate operational, administrative, management, and supportive services of a US post office, or coordinate activities of workers engaged in postal and related work in an assigned post office.

Median annual wage (2015): $70,640

Education required: High-school diploma or equivalent

Projected job openings (through 2024): 3,800

Work experience: Less than five years

On-the-job training: Moderate-term on-the-job training