This is a really important and good thing to ask, and let me tell you the interesting things I know...

Getting a state card is likely a very bad idea. It will show up on any background test, and it is hard to know when you will need to pass a background test. Specifically, it means you can not hold any government job, due to the drug-free workplace laws. This includes simple hourly jobs or even contracting jobs where you are not technically an employee. This latter example is something I have encountered - and I would have never predicted this. Government jobs account for a HUGE percentage of the economy, and i think any young or middle aged or even older person would be silly to risk it.

As for cards issued by clinics, each case seems to have different and unpredictable results. There have been battles over whether busted clinics have to turn over patient records to the state, and also over what to do with information that has already been turned over. This is not a small matter. Consider getting a recommendation from a private doctor who does not do this for a living exclusively, and keeping it handy, but avoiding being associated with the clinics that sell. Also know that you can get a card retroactively if you really do qualify in your state.

I hope this helps. It is an interesting issue and many people do not think about it enough. As for your insurance, your doctor would not know you have it unless you tell them. Yes I know this all sucks, I feel your pain, etc etc....