H.R. 3599: Joint Reserve Detachment (JRD) Formalization Act
Sponsor
Zachary Nunn
Republican · IA-3
Bill Progress
Latest Action · May 23, 2025
Referred to the House Committee on Armed Services.
Why it matters
As of the bill’s introduction on 2025-05-23, HR3599 would require—not merely allow—the Secretary of Defense to create and keep in place a Joint Reserve Detachment inside the Defense Innovation Unit.
What the bill does not do is also important. Based on the fact sheet, HR3599 does not specify how large the Joint Reserve Detachment must be, how much money must be spent, when exactly it must be established after enactment, or what penalties apply if the requirement is not met. So the bill locks in the requirement itself, but leaves implementation details to the Department of Defense.
What does H.R. 3599 do?
Makes creation mandatory in title 10
HR3599 amends section 1766(a) of title 10, United States Code, to require action by the Secretary of Defense instead of leaving it optional.
Changes one key phrase: “may” to “shall”
The bill replaces the original statutory language “may establish” with “shall establish and maintain,” converting discretionary authority into a legal obligation.
Applies specifically to the Defense Innovation Unit
The required detachment is the Joint Reserve Detachment of the Defense Innovation Unit, not a Pentagon-wide reserve force or a new stand-alone agency.
Requires ongoing operation, not just setup
By using the words “shall establish and maintain,” the bill requires the Secretary of Defense both to create the Joint Reserve Detachment and to keep it in place over time.
Introduced 2025-05-23 with 5 cosponsors
The measure was introduced on 2025-05-23 and had 5 cosponsors, showing some early support for formalizing the Defense Innovation Unit’s reserve detachment.
Who benefits from H.R. 3599?
Defense Innovation Unit
The Defense Innovation Unit benefits because HR3599 would make its Joint Reserve Detachment a required part of the organization under section 1766(a) of title 10, rather than something the Secretary of Defense may or may not establish.
Reserve personnel supporting defense innovation work
People serving through the Joint Reserve Detachment would benefit from a more stable legal footing, since the bill says the Secretary of Defense shall “establish and maintain” the detachment instead of merely having the option to do so.
Department of Defense program planners
Pentagon planners could benefit from clearer statutory direction because the bill removes ambiguity in section 1766(a) by changing “may establish” to “shall establish and maintain.”
Congressional overseers
Lawmakers benefit from a clearer benchmark for oversight: after enactment, they could ask whether the Secretary of Defense has complied with the requirement to establish and maintain the Defense Innovation Unit’s Joint Reserve Detachment.
Who is affected by H.R. 3599?
Secretary of Defense
The Secretary of Defense is the main regulated official affected, because HR3599 changes the Secretary’s authority from discretionary to mandatory under section 1766(a) of title 10.
Department of Defense
The Department of Defense would have to implement and sustain the Joint Reserve Detachment for the Defense Innovation Unit, even though the bill does not specify a funding amount, staffing level, or deadline.
Defense Innovation Unit leadership
Leadership at the Defense Innovation Unit would be affected because the unit’s reserve detachment would become a permanent statutory requirement rather than an optional organizational choice.
Future Pentagon leadership teams
Future administrations and Defense Department leaders would have less flexibility, since section 1766(a) would no longer let them decide whether to establish the Joint Reserve Detachment.
H.R. 3599 Common Questions
Does HR3599 require the Pentagon to create a Joint Reserve Detachment in the Defense Innovation Unit?
Yes. Under the Joint Reserve Detachment (JRD) Formalization Act, the Secretary of Defense shall establish and maintain a Joint Reserve Detachment of the Defense Innovation Unit (Section 2).
Can the Secretary of Defense choose not to set up the DIU Joint Reserve Detachment under HR3599?
No. According to HR3599 Section 2, the bill changes the law from discretionary to mandatory by replacing "may establish" with "shall establish and maintain."
What does HR3599 change in 10 U.S.C. 1766(a)?
Under the Joint Reserve Detachment (JRD) Formalization Act, Section 2 amends 10 U.S.C. 1766(a) so the Secretary of Defense must, rather than may, establish and maintain the DIU Joint Reserve Detachment.
Does HR3599 only require creating the DIU reserve detachment, or keeping it operating too?
It requires both. Under HR3599 Section 2, the Secretary of Defense must "establish and maintain" the Joint Reserve Detachment, meaning creation and continued operation.
Which Pentagon office gets the required reserve detachment under the JRD Formalization Act?
The Defense Innovation Unit. Under the Joint Reserve Detachment (JRD) Formalization Act (Section 2), the required detachment is specifically the DIU's joint reserve detachment.
Is HR3599 creating a Pentagon-wide reserve force?
No. According to HR3599 Section 2, the bill applies specifically to a Joint Reserve Detachment of the Defense Innovation Unit, not a department-wide reserve force.
Can the Defense Innovation Unit keep using optional authority for its reserve detachment after HR3599?
No. Under the Joint Reserve Detachment (JRD) Formalization Act (Section 2), optional authority ends because the statute is changed from "may establish" to "shall establish and maintain."
What are the exact words HR3599 uses to make the DIU reserve detachment mandatory?
HR3599 Section 2 uses the phrase "shall establish and maintain," replacing the prior wording "may establish" in 10 U.S.C. 1766(a).
Does HR3599 amend Title 10 of the U.S. Code?
Yes. According to HR3599 Section 2, the bill amends section 1766(a) of title 10, United States Code, to require the DIU Joint Reserve Detachment.
What is the short title of HR3599?
Under Section 1, HR3599 is titled the Joint Reserve Detachment (JRD) Formalization Act.
Based on H.R. 3599 bill text
HR3599 Legislative Journey
House: Committee Action
May 23, 2025
Referred to the House Committee on Armed Services.
About the Sponsor
Zachary Nunn
Republican, Iowa's 3rd congressional district · 3 years in Congress
Committees: House Select Committee on the Strategic Competition Between the United States and the Chinese Communist Party, Agriculture, Financial Services
View full profile →
Cosponsors (5)
This bill has 5 cosponsors: 2 Democrats, 3 Republicans, reflecting bipartisan support. Cosponsors represent 4 states: Hawaii, New York, Texas, and 1 more.
Committee Sponsors
Armed Services Committee
4 of 57 committee members cosponsored
27 Republicans across this committee haven't cosponsored yet. Mobilize their constituents
H.R. 3599 Quick Facts
- Committee
- Armed Services
- Chamber
- House
- Policy
- Armed Forces and National Security
- Introduced
- May 23, 2025
Referred to the House Committee on Armed Services.
May 23, 2025
Official Sources
Official congressional page for the Joint Reserve Detachment (JRD) Formalization Act, with status, text, sponsors, and actions.
Official U.S. Code page for section 1766 of title 10, the statute HR3599 would amend by changing 'may establish' to 'shall establish and maintain.'
Official Defense Innovation Unit website, relevant because the bill specifically requires a Joint Reserve Detachment within DIU.
Official Department of Defense website, relevant because the Secretary of Defense is the official required to establish and maintain the detachment.
Official source for the United States Code, useful background for understanding how HR3599 amends title 10.
Official GovInfo collection for the U.S. Code, providing authenticated federal statutory text related to title 10.
Official GovInfo repository for enrolled and introduced bill text, useful for locating the text of HR3599 and related legislative documents.
Official House committee site for the committee that commonly handles Armed Forces legislation such as amendments to title 10 involving the Defense Department.
H.R. 3599 Bill Text
“To amend title 10, United States Code, to require the Secretary of Defense to establish and maintain a joint reserve detachment of the Defense Innovation Unit, and for other purposes.”
Source: U.S. Government Publishing Office
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