5 CFR 1651.13 - How to apply for a death benefit.
The TSP has created a paper form that a potential beneficiary must use to apply for a TSP death benefit. The TSP must receive this form before a death benefit can be paid. Any individual can file this form with the TSP record keeper. The individual submitting the form must attach to the form a certified copy of the participant' death certificate. The TSP record keeper's acceptance of this form does not entitle the applicant to benefits. Please visit http://www.tsp.gov to obtain a copy of this form and for the current mailing address for death benefit applications.