Does Your Medicare Plan Cover B12 Shots? DYK your Medicare ABCs? Part A is for hospitalization insurance, Part B is for medical insurance, and Part A and Part B together are often called Original Medicare. Medicare Part C is Mic B12 Injections Cost (Price Ranges & Will Insurance Pay?) Eden What is Original Medicare Part B? What Does Medicare Actually Cover? Haven Shield Insurance Question of the Day:, How long does it take for a B12 injection to rev up the engines of energy? , For many people, the boost can be felt within 2448 hours. Others may notice gradual changes