# § 4023. Procurement for experimental purposes
**(a)** **Authority.—** The Secretary of Defense and the Secretaries of the military departments may each buy demonstrations, prototypes, products, supplies, parts, accessories, auxiliary services, and design for products or services that the Secretary of Defense or the Secretary concerned considers necessary for experimental or test purposes in the development of the best supplies that are needed for the national defense.
**1** **Procedures.—** Purchases under this section may be made or modified inside or outside the United States and by contract or otherwise. Chapter 137 [^1] of this title applies only when such purchases are made in quantities greater than necessary for prototyping, experimentation, technical evaluation, assessment of operational utility, or safety or to provide a residual operational capability.
See References in Text note below.
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**Source Credit**: (Added Pub. L. 103–160, div. A, title VIII, § 822(c)(1), Nov. 30, 1993, 107 Stat. 1706, § 2373; amended Pub. L. 103–337, div. A, title X, § 1070(g), Oct. 5, 1994, 108 Stat. 2859; Pub. L. 104–106, div. A, title VIII, § 812, Feb. 10, 1996, 110 Stat. 395; Pub. L. 114–92, div. A, title VIII, § 814, Nov. 25, 2015, 129 Stat. 893; Pub. L. 115–232, div. A, title VIII, § 886, Aug. 13, 2018, 132 Stat. 1916; renumbered § 4023, Pub. L. 116–283, div. A, title XVIII, § 1841(b)(1), Jan. 1, 2021, 134 Stat. 4243; Pub. L. 117–81, div. A, title XVII, § 1701(u)(2)(B), Dec. 27, 2021, 135 Stat. 2151; Pub. L. 119–60, div. A, title XVIII, § 1831, Dec. 18, 2025, 139 Stat. 1252.)
## Editorial Notes
### References in Text
Chapter 137 of this title, referred to in subsec. (b), was repealed by , , , effective , in conjunction with the transfer and reorganization of acquisition provisions in this title by , , . For definition of “chapter 137 legacy provisions”, see .
### Prior Provisions
A prior section 4023, , , related to employment of civilians in service club and library services, prior to repeal by , , .
Provisions similar to those in this section were contained in sections 4504 and 9504 of this title, prior to repeal by .
### Amendments
2025—Subsec. (a). , substituted “demonstrations, prototypes, products, supplies, parts, accessories, auxiliary services, and design for products or services” for “ordnance, signal, chemical activity, transportation, energy, medical, space-flight, telecommunications, and aeronautical supplies, including parts and accessories, and designs thereof,”.
Subsec. (b). , inserted “or modified” after “may be made” and “prototyping,” after “greater than necessary for”.
2021—, as amended by , renumbered as this section.
2018—Subsec. (a). inserted “telecommunications,” after “space-flight,”.
2015—Subsec. (a). , inserted “transportation, energy, medical, space-flight,” before “and aeronautical supplies”.
Subsec. (b). , substituted “only when such purchases are made in quantities greater than necessary for experimentation, technical evaluation, assessment of operational utility, or safety or to provide a residual operational capability” for “only when such purchases are made in quantity”.
1996—Subsec. (b). inserted “only” after “applies” in second sentence.
1994—Subsec. (a). substituted “chemical activity, and aeronautical supplies,” for “and chemical activity supplies,”.
## Statutory Notes and Related Subsidiaries
### Effective Date of 2021 Amendment
Amendment by applicable as if included in the enactment of title XVIII of as enacted, see , set out in a note preceding and note below.
Amendment by effective , with additional provisions for delayed implementation and applicability of existing law, see , set out as a note preceding .