The military missions of Department of Defense (DOD) units and organizations drive the need for facilities and the supporting infrastructure on any given military installation. Therefore, as the missions assigned to those organizations change, as organizations move to or away from an installation, or as buildings age or become obsolete, facilities and supporting infrastruct ure may need to be replaced or reconfigured. While each of the military departments has its own unique processes for vetting and setting military construction (MILCON) priorities, the MILCON process is formally structured to comply with the Planning, Programming, Budgeting and Execution (PPBE) process of the DOD. Moving from the realization of need (requirements determination) through the planning, programming, and budgeting process could take three or more years for a MILCON project. When adding the time required for congressional authorization and appropriations, implementation of the federal contracting process, and the physical construction of the project, the end-to-end military construction process―beginning with the realization of the need for a facility to the opening of its doors for occupancy―may span seven years or more. Chapter 169 of Title 10, United States Code, contains most of the laws governing m ilitary construction matters. Section 2801 provides definitions of certain terms used in the chapter and elsewhere in law. It defines the term military construction as "any construction, development, conversion, or extension of any kind carried out with respect to a military installation, whether to satisfy temporary or permanent requirements, or any acquisition of land or construction of a defense access road." It also specifies that a military construction project includes " all military construction work ... necessary to produce a complete and usable facility or a complete and usable improvement to an existing facility (or to produce such portion of a complete and usable facility or improvement as is specifically authorized by law). " Section 2802 specifies that the Secretary of Defense and the Secretaries of the military departments may carry out such military construction projects, land acquisitions, and defense access road projects "as are authorized by law." It covers the following activities: surveys and site preparation; acquisition, conversion, rehabilitation, and installation of facilities; acquisition and installation of equipment and appurtenances integral to the project; acquisition and installation of supporting facilities (including utilities) and appurtenances incident to the project; and planning, supervision, administration, and overhead incident to the project. The MILCON-unique requirements specified in 10 U.S.C. §2802 are in addition to 10 U.S.C Section 114, which states that, for specified DOD programs including military construction, "no funds may be appropriated for any fiscal year ... unless funds therefor have been specifically authorized in law" In the practical application of these statutes, Congress has required project-by-project authorization and appropriation for military construction projects. The annual Military Construction, Veterans Affairs, and Related Agencies appropriation bill provides funding for DOD construction activities. Often referred to as the MILCON/VA appropriations bill , the legislation appropriates project-specific amounts for major MILCON projects, and also funds a variety of construction and construction-related activities, including the following: Unspecified Minor Construction . Construction projects estimated to cost no more than $6 million under authority provided in 10 U.S.C §2805. Unlike major MILCON projects, unspecified minor construction projects are not subject to specific congressional authorization; therefore, the amounts are appropriated as unspecified minor construction . Planning and Design . Congress requires planning and design work on projected construction projects to be far enough along to provide confidence in the accuracy of the projected budget request. Accordingly, most of the construction projects included in the President's annual budget request are based on planning and design work that was funded by this nonspecific appropriation. Family Housing New Construction . Replacement, acquisition, expansion, addition, extension, and alteration of government-owned military family housing. Family Housing Operation and Maintenance . Debt payment, leasing, minor construction, principal and interest charges, and insurance premiums, as well as the provision of routine maintenance, utilities, and management of government-owned housing for families of servicemembers. DOD Housing Funds . Appropriations for the Family Housing Improvement Fund and the Military Unaccompanied Housing Improvement Fund to assure direct and guaranteed loans, utilize limited partnerships, and suggest DOD-owned property to encourage the private sector to increase available, affordable, and quality housing for military personnel. Base Realignment and Closure (BRAC) . Functions associated with the implementation of BRAC recommendations. North Atlantic Treaty Organization (NATO) Security Investment Program . U.S. contributions to the acquisition and construction of military facilities and installations and for related expenses for the collective defense of the North Atlantic Treaty Area. Chemical Demilitarization Construction . Military construction necessary to support the destruction of the U.S. stockpile of lethal chemical agents and munitions. In addition to containing the statutes that define and underpin the congressional process related to MILCON activities, Chapter 169 of Title 10 establishes several monetary thresholds that set the framework for the MILCON budget process and the congressional oversight of facilities-related activities of the DOD. In prescribing the various authorities and responsibilities, Chapter 169 often uses the term Secretary concerned , referring to the Secretaries of the military departments, or the Secretary of Defense in the case of a defense agency. In the case of MILCON thresholds, authorities, and limitations, it is important to note whether the authority applies to the Secretary of Defense or to each Secretary concerned individually. Appendix B provides a reference table for selected thresholds and associated requirements. In general, 10 U.S.C §2805 authorizes the Secretary concerned to use an expedited process for the authorization of unspecified minor construction projects―currently defined as a MILCON project costing $6 million or less (adjusted annually to reflect the area construction cost index ). Under this authority, any project costing more than $750,000 requires advance approval by the Secretary concerned. Section 2805 requires the Secretary concerned to fund unspecified minor construction projects only with minor military construction appropriations except in cases where the estimated total cost is $2 million or less. In this case the funds may be drawn from Operation and Maintenance (O&M) appropriations. In practice, these O&M-funded projects are referred to as minor construction projects. For UMMC projects exceeding $2 million (and therefore subject to MILCON appropriations), 10 U.S.C §2805 requires the Secretary concerned to submit a notification to the appropriate committees . The notification is to include a justification for the project and estimated cost. Following a 14-day waiting period, appropriations may then be drawn from an account set up by Congress in the MILCON appropriation for that purpose. In addition, 10 U.S.C. §2805 provides temporary authority (through September 30, 2025) for the use of O&M, as well as certain Research, Development, Test and Evaluation (RDT&E) appropriations, to fund certain UMMC projects intended to enhance DOD laboratories. Section 2802 of the FY2018 National Defense Authorization Act (NDAA/ P.L. 115-91 ) requires the Secretary concerned to adjust the dollar limitations specified in 10 U.S.C. §2805 for unspecified minor military construction projects inside the United States to reflect the area construction cost index for military construction projects (not to exceed $10 million). This requirement is in effect through fiscal year 2022. Section 2811 allows the Secretary concerned to carry out certain repair projects using O&M appropriations. The statute defines a "repair project" as a project "(1) to restore a real property facility, system, or component to such a condition that it may effectively be used for its designated functional purpose; or (2) to convert a real property facility, system, or component to a new functional purpose without increasing its external dimensions." There are no budgetary limitations or caps on the authority, but projects costing more than $7.5 million must be approved in advance by the Secretary concerned, and Congress must be notified of the decision to carry out the project. The notification must include a cost estimate and a justification for the project. If the cost estimate exceeds 75% of the estimated cost of a MILCON project to replace the facility, 10 U.S.C. §2811 also requires the congressional notification to include an explanation of the reasons why replacement of the facility is not in the best interest of the government. Section 2806 allows the Secretary concerned to obtain architectural and engineering services, and to initiate construction design, in connection with MILCON and family housing projects. If the required services are estimated to exceed $1 million, congressional notification is required and the Secretary concerned must wait 14 days before obligating funding for such purposes. The services may be paid for using MILCON or Family Housing planning and design appropriations. Section 2804 permits the Secretary of Defense to use or authorize the military secretaries to use appropriated military construction funds to carry out any project without prior congressional authorization if the Secretary determines that waiting to include it in the next military construction authorization would be "inconsistent with national security or national interest." The section requires the Secretary to report the project in writing to the appropriate congressional committees justifying the project and the invocation of this authority and estimating its cost. A Secretary of a military department may initiate a construction project if he or she determines that (1) it is vital to national security or to the protection of health, safety, or the quality of the environment and (2), the project is of such urgency that it cannot wait for statutory authorization. When the Secretary concerned initiates such a project, Section 2803 requires that he report it in writing to the appropriate congressional committees (armed services and appropriations), including the justification for and estimated cost of the project, the reason why Section 2803 is being invoked, and the source of the funds being used.