Yes, you need sick notes for the ESA support group, as you need to submit this for your claim at the start. The sick note for ESA Support group may be acquired from a GP or a psychiatrist or other medical professional relevant to your case, and after 13 weeks of submission of the sick note Jobcentre Plus will do their own medical test and you will no longer need fit notes. Claims for the ESA may also be backdated for up to three months.