With open enrollment for benefits in full swing, U.S. workers are seeing more high-deductible health plans from cost-conscious employers.

A new report finds that 36 percent of large employers offered consumer-directed, high-deductible health plans in 2012, up from 14 percent five years ago. Enrollment in those plans has risen to 16 percent of all covered employees, compared with 5 percent in 2007, according to benefits consultant Mercer.

Employers are pushing these plans in part because they are about 20 percent cheaper than the cost of a conventional PPO — or preferred-provider organization — plan, Mercer said. The cost of a high-deductible medical plan with a health savings account is $7,833 annually per employee compared with $10,007 for a PPO plan.

“If we’re not already at the tipping point for consumer-directed health plans — and we may well be — at this rate of growth, it’s coming soon,” said Laura Baker, a senior health and benefits consultant for Mercer.

The minimum deductible for these plans with a health savings account is $2,400 for a family this year and $2,500 next year under federal rules.

Overall, Mercer found that health benefit costs per employee rose 4.1 percent this year, the smallest increase since 1997 in its annual employer survey. Government and other groups have reported a similar slowdown in health-care spending.