@1m8
The same employee can pay for 2 different employer's medical plans but doing so is foolish, insane and simply flushing money down the toilet. It will also cause a logistical nightmare.
If or when you or the doctors need to file a claim, both medical plans will NOT pay for the medical treatment and/or prescription medication.
Let's say at Citi you had Aetna Insurance, and at Company-B you have United Healthcare Insurance. Your doctors or you file a claim with both insurance companies. The first one, Aetna will most likely deny your claim because you have a new employer, Company B and new insurance. In fact, both Aetna and UHC may deny your claim until you sort out and designate which insurance company should pay the claim.
Why would anyone in their right mind pay 2 insurance companies for the same coverage ?This is like buying 2 Auto insurances for the same car.
Also, if the doctors file the claim with 2 different insurance companies that's double dipping and double charging for the same treatment, which I believe is illegal.
Same with Dental Insurance.