Where can i go for group health insurance?

I need to find a group i can be insured with because i will no longer be able to have preexisting conditions covered under an individual plan. i've been told there are professional or other types of organizations which I could belong to, for which group insurance is available to their members. i'd join any organization if i could qualify, to obtain insurance. i have worked in the accounting, IT, hospitality, management, business and wine industries... Thanks