From the Washington Post:

So some folks were startled to learn that the new “self plus one” option in the Federal Employees Health Benefits (FEHB) program can be more expensive than family coverage, depending on the company. This option allows enrolled federal workers and retirees to purchase health insurance for themselves and one eligible family member.  Open season, when health plans can be chosen, begins Monday and runs through Dec. 14.

With health insurance costs for FEHB participants rising by an average of 7.4 percent next year, the most since 2011, enrollees are looking for any break they can get. Unfortunately for older people, health-care expenses rise with age and they are more likely to want self-plus-one policies

“There is a limit to how much the government will contribute towards the cost of a Self Only, Self Plus One, or Self and Family enrollment,” John O’Brien, OPM’s director of health care and insurance, said by e-mail. “The government contributes the lesser of the maximum contribution or 75 percent of the total premium. The remaining amount is the enrollee share (how much the enrollee must pay). In some cases, such as plans with a premium cost that is above the program average, this calculation may result in a higher enrollee share for a Self Plus One enrollment than a Self and Family enrollment.”

The choices employees and retirees make during open season will take effect in January. For 2016, they can choose from 252 health plans. OPM said its negotiations with insurance companies “were geared to keeping premium increases as low as possible without asking enrollees to pay substantially more money out of their pockets each time they need health care.”

Self Plus One FAQ