If you are invited to provide a blood sample, there will be no cost to you and you may be paid for your time. Participants in the ADNI4 Blood Biomarker study will be given $70 in an eGift Card. ADNI has partnered with Tango to provide eGift cards. Tango offers hundreds of digital gift cards as well as charitable donation options you can choose from. You can select eGift Cards from one or multiple vendors for a total of $70. The eGift Card is our way to thank you for traveling to a Quest location and providing a blood sample. Participants in the Blood Biomarker study can opt to not receive an eGift card. We may reach out to you by email or phone every 2 years to ask you to repeat the blood draw. If you provide additional blood samples in the future you will again be provided a $70 eGift Card.