Bottom line
The Standby Reserve is for Marines who keep a Reserve affiliation but are not assigned in the Ready Reserve. It has two lists: the Active Status List (ASL), where you can still earn retirement points and be considered for promotion (without pay), and the Inactive Status List (ISL), where you cannot train, cannot earn points, and cannot be promoted. Both are administratively supported by COMMARFORRES/MCIRSA but controlled by DC M&RA. You are screened while you are on either list, and that screening decides whether you move back to the Ready Reserve, shift between the two lists, retire, or get discharged.
What it means for you
If you cannot participate in the Ready Reserve right now (a hardship, a missed physical, a key civilian job, an unfulfilled service obligation), you may land in the Standby Reserve instead of being discharged. Where you land matters.
- On the ASL, you stay connected. No pay, but you can volunteer for training, earn retirement credit points, and be considered for promotion up to colonel.
- On the ISL, you are essentially parked. No training, no points, no pay, no promotion. Time on the ISL does not count toward retirement, and being assigned to it ends your current anniversary year for Reserve retirement.
The Director, Marine Corps Individual Reserve Support Activity (Dir MCIRSA) runs the paperwork and the screening. You can request a move back to active status when your situation changes.