Domestic Partner Configuration

Summary

Can anyone give guidance on domestic partner configuration for medical/dental/vision

Content

Hi All,  My company is considering implementing domestic partner to our Benefits Program for Open Enrollment.  I understand that there are tax implications but I am not clear on the setup.  Can anyone provide guidance on what their setup might be?  I read somewhere that I would need 4 rates for each plan.  Currently, we offer Employee Only, Employee + Spouse, Employee + Children and Family....would we need to add Employee + Domestic Partner and Family + DP.  

Any information would be greatly appreciated.