Open Question: My insurance through my employer is showing up as Savings Direct Deposit PreNote, whats this mean?

I was looking at my Pending ACHs on my online banking and noticed my health insurance provider's name was listed in pending deposits. It says it is a 'pre note'. I have used them for the first time over the past 6-8 weeks and the evaluation of my benefits for the services are still in processing. I haven't paid anything yet and am still waiting to hear back from my insurance company in regards