; 128 Stat. 3651). (b) Covered Parts Defined In this section, the term covered parts means commercially available off-the-shelf items as defined in section 104 of title 41, United States Code. C Defense-wide, Joint, and Multiservice Matters 121. F–35 Economic order quantity contracting authority The Secretary of Defense may enter into one or more contracts during fiscal year 2018 for the procurement of economic order quantities of material and equipment that has completed formal hardware qualification testing for the F–35 aircraft for use in procurement contracts to be awarded during fiscal years 2019 and 2020. The total amount obligated under all contracts entered into under this section shall not exceed $661,000,000. II RESEARCH, DEVELOPMENT, TEST, AND EVALUATION 201. Authorization of appropriations Funds are hereby authorized to be appropriated for fiscal year 2018 for the use of the Department of Defense for research, development, test, and evaluation as follows: (1) For the Army, $9,425,440,000. (2) For the Navy, $17,675,035,000. (3) For the Air Force, $34,914,359,000. (4) For Defense-wide activities, $20,490,902,000. (5) For the Director of Operational Test and Evaluation, $210,900,000. III OPERATION AND MAINTENANCE 301. Operation and maintenance funding Funds are hereby authorized to be appropriated for fiscal year 2018 for the use of the Armed Forces and other activities and agencies of the Department of Defense for expenses, not otherwise provided for, for operation and maintenance, in amounts as follows: (1) For the Army, $38,945,417,000. (2) For the Navy, $45,439,407,000. (3) For the Marine Corps, $6,933,408,000. (4) For the Air Force, $39,429,232,000. (5) For Defense-wide activities, $34,709,717,000. (6) For the Army Reserve, $2,906,842,000. (7) For the Navy Reserve, $1,084,007,000. (8) For the Marine Corps Reserve, $278,837,000. (9) For the Air Force Reserve, $3,267,507,000. (10) For the Army National Guard, $7,307,170,000. (11) For the Air National Guard, $6,939,968,000. (12) For the United States