8eb4e8a0_se_Security_Cooperation_Agency__Definition
[Term] Operation & Maintenance (O&M) Costs [Link] N/A [Definition] 
Costs associated with equipment, supplies, and services required to train, operate, and maintain forces in a recipient country, including the cost of spare parts other than concurrent spares and initial stockages, ammunition and missiles used in training or replacements for such items expended in training or operations, rebuild and overhaul costs (excluding modernization) of equipment subsequent to initial issue, training and other services that do not constitute investment costs, and administrative costs associated with overall program management and administration.
ESAMM Glossary | Defense Security Cooperation Agency
Definition