Pension Question

If you’re vested in the pension of a company that you haven’t worked in for years and years, how do you know what’s up with it?
Specifically, I worked for Empire Blue Cross and Blue Shield many moons ago. The last address I had for them was 2 World Trade Center. They aren’t located there any more.

If there have been changes in the pension plan, shouldn’t I have been notified? I lived at the same address until a year ago and I never got anything from them after I was laid off. Now that I’ve moved I wanted to notify them, but I don’t know where they are.
In general-- how does a person keep track of these kinds of things? Is the onus on the former employee or does the employer have to keep track of their future pensioners?

Empire BlueCross BlueShield
11 W. 42nd St
New York, N.Y. 10036
Telephone: 1-212-476-1000
Fax: 1-212-476-1281

Can’t answer the pension thing, but I did see that their pension plan is covered by ERISA, so maybe you want to look that up.