Employers are increasingly pushing enrollment in high-deductible, low-premium health insurance plans, according to benefits experts, which means it might be time to break out the calculator and reconsider current policies.

Employees across the country are getting their first looks at what they will be paying for health insurance in 2015 with the start of open enrollment, the annual window in which workers can make changes to their elected benefits, including health insurance. Open enrollment is typically held in October and November each year.

"Don't assume that nothing's changing even if your current option is still available," said Craig Rosenberg, practice leader of health and welfare benefits at consulting firm Aon Hewitt. "There are probably some new choices that are available for you."

Three-fourths of employers aim to offer high-deductible plans coupled with a health savings account in the next three years, and 20 percent will offer only those type of plans, according to data from Mercer, a financial services company with a health and benefits arm. To qualify for a health savings account, a plan has to have a minimum deductible of $1,250 for employee-only coverage and $2,500 for family coverage.

Overall costs likely will rise again in 2015, by about 4 percent, according to Mercer, modest compared with previous years. But some employees are seeing much sharper increases, making high-deductible plans more attractive.

High-deductible, low-premium plans are often called consumer-directed health plans and paired with a health savings account that allows workers to pay for eligible expenses with tax-free dollars.

Employers have a financial incentive to offer such plans. Under the Affordable Care Act, employers in 2018 that offer plans that cost more than $10,200 for an individual, or $27,500 for a family will be charged a 40 percent tax on the amount exceeding the threshold. By raising deductibles and lowering premiums, companies will lower their chance of triggering the tax.

Nancy Coletto, a Chicago-based partner in Mercer's health and benefits practice, said employer health-insurance plans are more likely to add a fee for dependents.

"Health care reform puts more responsibility on employers to cover more of their employees," Coletto said. "Employers who are now covering more employees may make it more expensive to cover a dependent. Make sure you fully understand what costs are changing."