Treat and Reduce Obesity Act of 2021 This bill expands Medicare coverage of intensive behavioral therapy for obesity. Specifically, the bill allows coverage for therapy that is provided by (1) a physician who is not a primary care physician; or (2) other health care providers (e.g., physician assistants and nurse practitioners) and approved counseling programs, if provided upon a referral from, and in coordination with, a physician or primary care practitioner. Currently, such therapy is covered only if provided by a primary care practitioner. The bill also allows coverage under Medicare's prescription drug benefit of drugs used for the treatment of obesity or for weight loss management for individuals who are overweight.