Various methods of non-invasive brain stimulation (NIBS) have been studied for the treatment of mild cognitive impairment (MCI) and dementia in people with Alzheimer disease (AD). Device-based NIBS techniques modulate brain function by inducing electric fields in the brain. Most studies have tested multiple sessions of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS); however, other emerging approaches have shown promising results, including transcranial alternating current stimulation (tACS) and temporal interference stimulation (TIS). Here, I summarize the various techniques and their individual benefits.