With Administrator-level access, you can add an Insurance Note Type in your Validation Tables (from the Settings menu). You will then need to assign this Note Type to the Profiles (groups of Users) who need to access it.
After your new Insurance Note Type is set up and assigned to the Profile(s) of Users that you determine, a User from that Profile can:
Click +Add Note in a Client's record (in the Activity Stream)
Select Insurance in the Note Type field
Enter any insurance or Medicaid information that needs to be collected
Click Save
The following articles will help you further: