What do you do with old retirement/HSA accounts?

I started a new job last year. My new job offers 401(k) and HSA accounts through Fidelity. My previous employer offered them through Principal and Wex.

I have been looking for an opportunity to open accounts with fidelity and this was a great opportunity to do that.

I rolled over my previous accounts to fidelity successfully. But now I have empty accounts at Principal and Wex. I waited until after I filled my taxes to see if I received any forms from them. But nothing that affected my taxes.

Now what do I do with this accounts? Do I close them? Can I close them? Do I keep managing them forever?

I would like to end my relationship with these institutions and cut down on my exposure with empty accounts hanging around.

Any thoughts?

I closed my old 401k and HSA accounts. I kept my records of out of pocket medical expenses and post retirement I used my HSA account balance to pay for medical expenses.