They pay medical when you submit a claim and do not wait for all the deductions. If you use your entire election by February for example, they reimburse you the whole enchilada BEFORE they deduct from your paycheck. Only the dependent care claims are subject to waiting until they have actually been deducted from your check.
I can confirm this. In fact, things are interesting if you signed up of medical expense account, submit and get your claim for the full amount, and pay into the account per pay period therafter.
If you signed up for a $3000 account for that year, you have access to the full amount. But you pay into the account per pay period, for the rest of the year…The implications of spending your account and leaving the employer before the full year is over is left as an exercise for the reader.