Only the entire medical FSA or limited purpose FSA election amount is available just after the beginning of the new year for your use. You may spend up to the full balance at any time on eligible health care expenses. Reminder: L-FSA is only for eligible vision and dental expenses, and you cannot use this plan for medical or prescription drug expenses.
The DC-FSA funds are only available for use on eligible dependent care expenses as they are taken out of your paycheck and sent to the flex vendor. In other words, you may only spend the DC-FSA funds that are in your account at any point in time.
Find more FSA-related FAQs here: https://www.optumbank.com/tennessee/customer-support/faqs/fsa-faqs.html.