The U.S. Office of Personnel Management (OPM) is issuing an interim final rule to extend eligibility for coverage under the Federal Employees Dental and Vision Insurance Program (FEDVIP) to certain TRICARE-eligible individuals. First, on December 23, 2016, the National Defense Authorization Act (NDAA) for Fiscal Year 2017 was signed into law and it expanded FEDVIP eligibility to certain TRICARE-eligible individuals. The statutory deadline making FEDVIP dental and vision benefits available to TRICARE-eligible individuals is "on or after January 1, 2018,” and this regulation proposes enrollment during the 2018 Open Season for coverage in plan year 2019. Second, this rule would expand eligibility for enrollment in the FEDVIP to certain Federal employees on temporary appointments and certain employees on seasonal and intermittent schedules that became eligible for Federal Employees Health Benefits (FEHB) enrollment beginning in 2015. Third, this rule expands access to the FEDVIP to certain firefighters on temporary appointments and intermittent emergency response personnel, the same group that gained eligibility to enroll in the FEHB Program beginning in 2012. Finally, this rule includes certain technical corrections, and establishes effective dates of enrollment in the FEDVIP.