You can keep that one PACER account for case research only.  However, each attorney with an e-filing account with the court needs his or her own individual PACER account. 

Go to pacer.uscourts.gov to register for your own PACER account. 

See Registering for a PACER Account for instructions.

Did you upgrade your PACER account on the PACER website? If you are not sure, log in to your PACER account and select Manage My Account and see what type of account you have. 

If the Account Type is Legacy PACER Account, click on the Upgrade link and complete the upgrade process. If the Account Type says Upgraded, then you are ready for NextGen.