You can only qualify through the PSAT--not the SAT.
National Merit Scholarship Program: The National Merit Scholarship Program is the oldest and most recognized scholarship associated with the PSAT. Nearly all US high school students who take the PSAT are entered into the competition, which rewards the highest-scoring students with scholarships from NMSC, local corporations, or subscribing colleges. The top 3% to 4% of test takers are recognized as "Commended Students," and their names are submitted as such to two colleges of their choice. Of these approximately 50,000 Commended Students, 16,000 are selected as National Merit Semifinalists based on their PSAT score and their state of residence. NMSC designates a specified number of Semifinalists from each state in order to ensure that all states are represented, and then selects 15,000 of these students as National Merit Finalists. Each Finalist must submit an application, an official SAT score, and a letter of recommendation from the high school principal in order to compete for scholarships. More than 8,000 will win a merit scholarship based on their PSAT and SAT scores. To learn more, visit the NMSC website at www.nationalmerit.org
You can compare your SAT percentiles here: http://www.collegeboard.com/prod_dow...ntileRanks.pdf