For families new to college and the financial aid process, BASE year is the year the the colleges (and government) will use to determine your EFC (Expected Family Contribution). Your base year is also referred to as prior-prior year. The financial aid forms will require parents and students income and tax information from your base year to determine your aid eligibility for the current or upcoming semester. For example if your are applying for financial aid now for your class of 2021 high school senior, you are applying for financial aid to be disbursed to your student in the Fall of 2021 as a college freshman. The FAFSA will require you to provide income and tax information form 2019 which is two years prior to enrollment. This has not always been the case. This change came about in recent years to prevent delays or inaccurate financial reporting from parents that have not filed taxes for the current year. The idea is that most if not all families will have their taxes done (or should have them done) within 2 years. There is a new base year every year. So if you lose your income or receive a large bonus (or did 2 years ago) it can have a delayed impact on your financial aid eligibility. Understanding the impact of your base year is crucial when creating a plan to maximize your financial aid. Please note that base year has no impact on your assets. Your assets will impact your aid eligibility on the day you apply for financial aid unlike your income.