Oxford Health Plan (3,200 employees) site is running Apache/2.0.47 and is down

I would guess this is highly insecure given that it was released on 10th July 2003 (It's obviously unstable given how the site is failing).

If you try to search for providers they work with here (As of 10/11/2014), https://www.oxhp.com/secure/providerSearch/content_facility.html

The site fails and spits out: Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, you@your.address and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

IBM_HTTP_Server/6.1.0.47 Apache/2.0.47 (Unix) DAV/2 Server at www-int.oxhp.com Port 80