Expand American Educational Opportunity Act of 2021 This bill replaces the Hope Scholarship and Lifetime Learning tax credits with a modified American Opportunity Tax Credit that (1) allows an income tax credit of up to $2,500 of the qualified tuition and related expenses of a student who is carrying at least one half of a normal course load, (2) allows a lifetime dollar limitation for the credit of $15,000 for all taxable years, and (3) increases the refundable portion of the credit to a maximum of $1,500. The bill defines qualified tuition and related expenses as tuition, fees, computer or peripheral equipment, child and dependent care expenses, and course materials for the taxpayer, the taxpayer's spouse, and dependents at certain postsecondary educational institutions. The bill also allows an exclusion from gross income, for income tax purposes, of any amount received as a Federal Pell Grant.