Can you go on your boyfriends health insurance?

Unless they are legally able to be listed as a domestic partner they cannot be added to a plan.

Domestic Partnership is something that some plans allow and some do not, it can be excluded by an Employer Plan as well.

They define dependant as a spouse/ domestic partner or child.

You will need to check with your plan and also if Domestic Partnership is required, contact your city hall and ask them what the qualifications are to meet it. In some places you have to have lived in the same dwelling and can prove you have shared expenses for 7 or more years, for example.