125 Plans/ Debit Cards: Is there a grace period at the end of the plan year in which I can continue to access last year’s deferrals?

You will need to check your plan. Your plan may include a grace period or it may include a rollover provision. If your plan allows purchases during the “grace period” then purchases made during this time are automatically applied to any remaining prior year’s balance first, allowing you to use your funds without having to file claims.