Editor's Note: APYs listed in this article are up-to-date as of the time of publication. They may fluctuate (up or down) as the Fed rate changes. CNBC Select will update as changes are made public.

Big, one-time or infrequent expenses — a Disney vacation, new Apple Watch or next year's car insurance premiums can be budget busters. Because these expenses don't occur regularly, you may struggle to ...