Employers expect a 4.1% rate of increase in the cost of employer-sponsored health care benefits in 2015 — the lowest in 15 years but well above inflation, according to an annual survey by global professional services company Towers Watson (NASDAQ: TW) and the National Business Group on Health (NBGH), an association of large employers.

The widely cited survey of 487 large U.S. employers also found that while employers remain concerned about the cost and effectiveness of their programs, they are more committed to providing some form of health care coverage to employees during the next 10 years than they have been in recent years.

Employer confidence in offering health care coverage 10 years from now has nearly doubled to 44% today, from 25% in 2014.

The findings of the 20th annual Towers Watson/NBGH Best Practices in Health Care Employer Survey point to a growing affordability challenge for employees, especially for lower-wage workers. Health care costs for 2015 are expected to average $12,041 per employee, up from $11,567 in 2014.

On average, employees will pay 22.2% of total premium costs in 2015, which in payroll deductions translates into an average employee contribution of $2,676, or $223 a month.

Employer actions taken and planned include: 

• Curbing the high cost of specialty pharmacy through new coverage/utilization restrictions:53% of employers have done so already; another 32% are likely to by 2018 
• Adopting spousal surcharges: 27% of employers have implemented; could rise to nearly 60% in three years
• Using a defined contribution strategy instead of defined benefit: 20% today; expected to double by 2018
• Offering more customization by adding voluntary benefits: 34% today; could reach 70% by 2018