A 1959 Cadillac Coupe de Ville

Obamacare's "Cadillac tax" doesn't kick in until 2018, but that isn't stopping companies from worrying about it now—and taking steps to avoid it later.

Nearly 3 out of 4 companies polled in a new survey by employee benefits consulting firm Towers Watson said they're either "somewhat" or "very" concerned they will get whacked with that hefty tax targeted at high-cost health plans, either because of what those plans already cost or where they are headed.