Leidos Inc., Reston, Virginia (HDTRA1-17-C-0019), is issued a contract modification (P00031) to exercise an option for a six-month extension with a ceiling value of $18,664,816, to a time-and-materials contract for scientific and technical services in support of various projects under the Biological Threat Reduction Program. Work will be performed at various locations throughout the world. The anticipated completion date is Nov. 13, 2022. The contract was a competitive acquisition; the government received 11 offers. The Defense Threat Reduction Agency, Cooperative Threat Reduction Contracting Office, Fort Belvoir, Virginia, is the contracting activity. (Awarded May 13, 2022)