Yes, you may be eligible for USAA membership if your grandfather served in the military, but there are specific conditions. USAA membership eligibility typically extends to:
If your parent (your grandfather's child) is or was a USAA member, you may be eligible to join through them. However, if your grandfather was a member but your parent never joined, you wouldn't qualify directly. The eligibility chain must be maintained through consecutive generations.
You can contact USAA directly to confirm eligibility based on your family's military history and membership status.