Using Top-Up benefits may be an option if you plan to use tuition assistance (TA) to complete a degree program while on active duty and don’t plan to continue your education after service.
Top-Up can also be helpful for just taking a few courses with TA while on active duty: you can save most of your GI Bill benefits for after service to complete your education program.
Contact your VA School Certifying Official on how this may work for you.