ARServices Ltd., Alexandria, Virginia, is being awarded a cost-plus-fixed-fee contract providing advisory and assistance services expertise for the Defense Threat Reduction Agency (DTRA) in support of the Research and Development (RD) Directorate in the areas of programmatic, financial and policy expertise across the chemical, biological, radiological, nuclear and high-yield explosives spectrum, and in the countering weapons of mass destruction, countering improvised threats, and countering improvised threat networks mission domains that RD supports. The face value of this action is $16,258,032, the total cumulative face value of this not-to-exceed contract is $145,518,032. The period of performance is a six-month base period and four one-year option periods, and is expected to be completed by Nov. 15, 2025. The work will be performed at multiple DTRA locations, primarily at Fort Belvoir, Virginia. Fiscal 2020 research, development, test and evaluation funds in the amount of $1,117,675; fiscal 2021 research, development, test and evaluation funds in the amount of $2,744,872; and fiscal 2021 operation and maintenance funds in the amount of $3,376,391 are being obligated at the time of award. This acquisition is a small business set-aside; competitive proposals were solicited and six offers were received. The Defense Threat Reduction Agency, Fort Belvoir, Virginia, is the contracting activity (HDTRA121C0042).