The health insurance program covering federal employees in 2014 will continue to emphasize cost controls for prescription drugs, which account for about 30 percent of the premiums, the Office of Personnel Management announced Thursday.

“Maximizing the effective use of medications and controlling pharmacy costs should be a central theme of 2014 benefit proposals,” OPM said in its annual “call letter” to insurance companies participating in the Federal Employees Health Benefits Program. “Additionally, we seek to synchronize pharmacy benefit designs so that enrollees may make meaningful comparisons between plans.”

The letter was released Thursday morning at a conference that begins negotiations over coverage and premium rates for the following year, which typically are announced in September. During an open season from early November to early December eligible persons may enroll, switch plans or change types of enrollment—for example, moving from self-only coverage to self and family coverage.

The FEHBP is the largest employer-sponsored health insurance program in the country, covering about 8.2 million federal employees, retirees and certain survivors and family members. There are more than 200 plans, some nationwide but most health maintenance organizations available only regionally. The government pays about 70 percent of the total premium cost for retirees and for non-postal employees; the U.S. Postal Service pays somewhat more for its employees.

OPM has been targeting the cost of prescription drugs in recent years, emphasizing the use of generics and therapeutic equivalents over brand-name drugs, for example. Over 2014-2016, health plans are to divide their drug coverage into four levels with a copayment structure that is easy for members to understand and that creates an “incentive to utilize generics and preferred brands.”

OPM also has emphasized wellness programs such as health risk assessments and encouraging healthy lifestyles. The letter sets new standards for such programs, saying “our most recent data reveals low levels of member participation. To have a greater impact on enrollee health, we strongly encourage carriers to re-examine the scope of their programs, outreach efforts, and the level of incentives.”

It also invited carriers to propose pilot programs for retirees who also have Medicare coverage. In that situation Medicare pays first and the FEHBP acts as a supplement, but the FEHBP premium costs to both the enrollee and the government stay the same.