So you're telling me that you expected the premium for covering two people to be the same as the premium for covering only one person?
Even if you had left it as a single coverage, chances are it would have gone up considerably at the anniversary. The cost of insurance is skyrocketing and many if not most small to medium sized employers are having to either increase the amount the employee pays, cut benefits, or both. Many smaller employers have had to cut health insurance altogether. I can't imagine how you and your co-workers managed not to hear this; it has been widely reported in the media for some years now.
With regards to the legality, off the top of my head I don't know what, if any, notification requirements Florida has for premium increases. Based on what I know of other Florida employment law, I frankly wouldn't be surprised if there are none. Florida has very few employment laws at the state level; they mostly follow the Feds and I don't think there's any Federal requirement. I know, that seems strange, but let me explain why: As an example, in my state there is a law that the insurance carrier has to give the employer 30 days notice of what they want for a premium increase. Notice that's the EMPLOYER, not the employees. The employer, receiving their 30 days notice, immediately sets to work trying to either negotiate the rates down or find a somewhat cheaper policy without decreasing benefits any more than necessary. (This is a major job function of most HR/Benefit managers!) It takes,say, 21-28 days to negotiate the rates to a level that is agreeable to both (and an HR manager who can do this in less is either working from a VERY strong position or else is VERY, VERY good at their job
) That gives the employer only 2-9 calendar days (fewer business days) to notify the employees before the new rates go into effect.
It is not impossible - in fact, it is quite likely - that the terms of the policy require that you show proof of other coverage before allowing you to drop the employer coverage. Many employer plans, especially if yours is a small employer, require 100% participation, and make exceptions only for those who can show proof of other coverage. In fact, if your share of the premiums are taken from your paycheck pre-tax, your employer would be violating the law if he allowed you to drop coverage even with such proof unless you could also show that you had had what is called a "qualifying event" (generally marriage, divorce, a birth or adoption) within 30 days of the date you drop coverage. When insurance premiums are taken pre-tax, the law limits an employees' option to make changes to coverage VERY severely.
While of course I don't have the quotes in front of me, I have to tell you that I find it difficult to believe that you can find COMPARABLE coverage for only half the cost of a group policy, unless your employer is being seriously overcharged. I have no doubt that you can find A policy that costs only half the cost, but I very much doubt that the less expensive policy will provide the same level of benefits for the money. I am speaking from the position of having 25 years experience administrating employer-sponsored benefit plans. The whole point of group plans is that they are able to provide better benefits for the same money by widening the risk pool. I would study those plans very, very carefully.