CRLLS
Thinks s/he gets paid by the post
What if you announce your plans now, to retire on a date AFTER you qualify for retiree health care? Then decline the transfer to the new company. Heck, they may even rescind the offer. You will likely protect your health care benefits. What happens after that is up to you. Find another job, or possibly apply to the new company, expecting to be let go within a year. It may be at a higher pay level than if you transferred. They already have indicated they want you and they will lose that expertise if you retire.