32 C.F.R. Appendix A to Part 44
(b) Key position guidelines:
(2) Consider the following questions to determine whether an individual position should be designated as a key position:
(5) When employers consider a Ready Reserve member as filling a key position within their organization, they should petition the applicable Reserve personnel center for discussion and adjudication. An employer may not take any employment action with regard to the position for which approval is sought based upon an employee or potential employee's military service until such time as the petition for approval has been approved by the relevant Service Secretary. Below is the list of Reserve personnel centers to which petitions shall be forwarded:
Army Reserve: U.S. Army Human Resources, Command 1600 Spearhead Division, Avenue ATTN: AHRC-ROR-PPA, Fort Knox, KY 40122-5100, https://www.hrc.army.mil/
Navy Reserve: Commander, Naval Military Personnel Command (Pers 91), 5720 Integrity Drive, Millington, TN 38055-9100, https://www.public.navy.mil/bupers-npc/Pages/default.aspx
Marine Corps Reserve: Director, Marine Corps Individual Reserve Support Activity (MCIRSA), 2000 Opelousas Ave., New Orleans, LA 70114, https://www.marforres.marines.mil/Major-Subordinate-Commands/Force-Headquarters-Group/Marine-Corps-Individual-Reserve-Support-Activity/
Air Force Reserve: Commander, Air Reserve Personnel Center/DPAM, 18420 E. Silver Creek Ave., Bldg. 390, MS 68, Buckley AFB, CO 80011, https://www.arpc.afrc.af.mil/
Coast Guard Reserve: Commander (PSC-RPM), U. S. Coast Guard Personnel Service Center, 2703 Martin Luther King Jr Ave. SE, Stop 7200, Washington, DC 20593-7200, https://www.dcms.uscg.mil/Our-Organization/Assistant-Commandant-for-Human-Resources-CG-1/Personnel-Service-Center-PSC/Reserve-Personnel-Management-PSC-RPM/
Army and Air National Guard: Submit petitions to the Adjutant General of the appropriate State, Territory, or the District of Columbia.