I don't have specific links, but a good search would find the lists of companies or from support groups you or your HR office can contact for additional information. From what I've read, the (employer) company is paying the SRS and not the health insurance company. It's a trend to lower health/medical costs for companies where they're paying (out of pocket) costs for a variety of surgeries and procedures, including some in foreign countries, eg. Thailand. It's actually cheaper to do this than pay increased premiums for all. Health insurance carriers seem to be staying the same with their coverages and policies for "transsexual" services. HRT on the other hand, is usually covered under drug policies as hormones are not gender/sex specific any more. Therapy is dependent on your carrier, which usually requires a diagnosis, treatment plan with goals and deadlines, and specific number of sessions per year and total. Some offer optional partial payment for more frequent or extended therapy.
That's my experience and understanding. Yours and others' experience may differ.
--Susan--