www.plasticsurgery.org/patients_consumers/links_resources
This explains the law in "non-legaleze". The federal law only relates to reconstruction after mastectomy. And the health insurance must cover any reconstuction or modifications for as long as you are a policy holder, for any reason (so if I decided I want "Dolly Partons" next year my insurance must pay for it). Things change when you switch to Medicare.
Unfortunatley I don't think the law covers lumpectomies. I have a dear friend of 15 years who was diagnosed at the same time I was. As she was ER+/PR-, Her2-, she opted for a lumpectomy. She is trying to get her insurance to cover modification of the lumpectomy sight and reduction of the other breast (she is a DDD cup). So far they have denied her.
I hope this helps clear things up.