Some of the merit based scholarship competitions end with high school, such as Intel and Siemens Science Talent Search. Two of the merit based science scholarships are Tylenol Future Care Scholarship (TFCS) and Thermo Fisher Pierce Scholarship (TFPS). The uniqueness of these scholarships is you can aim multiple times even if you miss in early try through undergraduate and postgraduate study. TFPS gives an option on the application for graduating high school seniors as well. TFCS requires atleast one year of College study. However, for TFCS graduating high school senior also eligible if s/he met the college study criteria while in high school. You can refer to the August 3, 2015 article by NSHSS, https://www.nshss.org/newsroom/news-items/2015-newsletter/august/member-highlight/. It has an example of a high school graduate reaching to the TFCS semifinalist level as of that time. Your study in high school won’t go away easily but strengthens the foundation. Do not give up even if you miss in your first effort. While aiming high, you can automatically achieve in other levels with a strong foundation.