How long do I have to use my GI Bill benefits?

Once you have separated from the service you have 15 years to use your Chapter 33 (Post 9/11) and 10 years for all other chapters. Although separating from service 'starts the clock' on your time limit, you should know that if you are recalled to active-duty for more than 90 days, during that period, your clock is reset. Your effective date is the date of your last discharge from active duty.