After Leqembi removes amyloid plaques from the brain, treatment isn't over. The brain continues to produce beta-amyloid every day, and in Alzheimer's disease a small amount escapes the brain's natural clearance systems. Without continued treatment, these molecules can gradually accumulate again, forming toxic oligomers, protofibrils, and eventually new plaques. This article explains why maintenance therapy is essential after the initial 18 months of Leqembi, compares monthly IV infusions with the FDA-approved IQLIK® self-injection, and provides a practical guide to Medicare Part B and Part D coverage, specialty pharmacies, formularies, prior authorization, and out-of-pocket costs so you can make informed decisions about your long-term treatment options.