The reigning assumption among many Americans is that teenagers go directly from high school to college, but that's not the way life always works.

Just 27% of Americans over age 25 hold bachelor's degrees or higher, according to 2004 Census data. See the Census data.

These days, that lack of a college degree is likelier to mean a steep hit to earnings. "Increasingly, the days of blue-collar jobs that have lower educational and skill requirements but pay an outstanding wage are disappearing," said Jerry Rubin, vice president of Jobs for the Future, a nonprofit research group that works with foundations and federal and state agencies to create job training programs.

But lack of a college degree doesn't have to mean slogging for a pittance in a dead-end job, according to a recent report by JFF.

The report details 16 jobs, all in growing industries, that pay more than $25,000 a year, are available to workers holding an associate's degree or less, and don't require a significant amount of previous work experience.

Those occupations include nursing, carpentry, bookkeeping, plumbers and electricians. (See full list below.)

"There's no question that the payoff for a college degree is highly valuable and getting more valuable every year, [but] there are major occupations with large numbers of jobs going wanting that pay reasonably good wages, and are within reach of working adults that don't yet have postsecondary education," Rubin said.

Some barriers to entry

But just because you don't necessarily need a college degree doesn't mean entry into these jobs is easy.

For instance, "registered nurse" tops the list of 16 jobs because it has the greatest number of projected annual job openings, but that job poses barriers for some lower-skilled entrants, including training programs that tend to be highly competitive and full-time.

"Registered nurse is certainly an excellent paying occupation and an occupation where there are tremendous shortages," Rubin said. But, he added, entry to the field usually requires at least three years of full-time study and "very, very strong math and science skills."

An alternative is to become a licensed practical nurse, another job on the list. Certification is often available through part-time training programs, making that occupation a more manageable entry point into the nursing field for those needing to support themselves and a family.

A similar caveat applies to the information-technology field, Rubin said, noting that IT personnel managers often seek applicants with on-the-job experience.

IT job-training programs that fail to include work experience or internship opportunities "are doing a disservice to the individuals trying to get into that industry," Rubin said. The JFF report is aimed at those who create job-training programs.

"Working people with limited skills and limited incomes don't have the time or resources to go down the wrong path," he said. "It's very important that any ... training institution has a very fine-grained understanding of what employers are looking for."

There are few barriers into the field of "customer-service representative," but workers often don't last long on the job because of "highly routinized work and a stressful emotional environment" from dealing with irate customers, according to the report.

For more details on the pros and cons of each of the occupations listed, read the full report. See the full report as a PDF document.

List of jobs

Together, the following 16 occupations are projected to create more than 700,000 new jobs nationally each year, according to JFF.

The jobs are ranked by annual projected job openings. For instance, the "registered nurse" category is forecast to create 110,119 new jobs annually, while it's estimated there will be 20,511 new jobs for plumbers, pipefitters and steamfitters each year.

The dollar amount represents median earnings for each occupation, according to JFF.

1. Registered nurse, $48,090
2. Customer-service representative, $26,240
3. Sales representative (in nontechnical wholesale and manufacturing), $42,730
4. Truck driver, heavy and tractor-trailer, $33,210
5. Maintenance and repair worker, general, $29,370
6. Bookkeeping, accounting and auditing clerk, $27,380
7. Executive secretary and administrative assistant, $33,410
8. Secretary (not legal, medical and executive), $25,290
9. Carpenter, $34,190
10. Automotive-service technician and mechanic, $30,590
11. Police and sheriff's patrol officer, $42,270
12. Licensed practical and licensed vocational nurse, $31,440
13. Electrician, $41,390
14. All other sales and related workers, $35,170
15. Computer-support specialist, $39,100
16. Plumber, pipefitter and steamfitter, $40,170

Note that the report uses national employment data. Local labor markets will vary.