CFR > Title 5 - Administrative Personnel > CHAPTER I—OFFICE OF PERSONNEL MANAGEMENT > SUBCHAPTER B—CIVIL SERVICE REGULATIONS (parts 110 to 990) > PART 843—FEDERAL EMPLOYEES RETIREMENT SYSTEM—DEATH BENEFITS AND EMPLOYEE REFUNDS > SUBPART E—Insurable Interest Annuities (§843.501 to §843.504) > 843.501—Purpose.