The highest yield will be an audition at a program you are interested in. Other options would include either a virtual rotation (which I have heard of but never personally done. I cannot speak to how good of an experience this is or is not) or reaching out to PM&R physicians in the community to rotate with. I would try and get experience with both inpatient (either inpatient rehabilitation, skilled nursing facility, long-term acute care facility) and outpatient (either general outpatient PM&R, interventional pain, sports-trained PM&R in maybe an orthopedics group, or interventional spine). I know I am missing other aspects of PM&R (amputee rehab, cancer rehab, pediatric rehab, etc.) but these things may just be harder to find. I agree with the above, you need exposure to know this is what you want.