At the start of a new year, many employees and retirees change health plans and often wonder what happens if they are in the middle of being treated for a health problem. All services or benefits you receive up to midnight before the change occurs are paid by your former plan or option; all those occurring after midnight will be handled by your new plan or option. 

While the billing and payment of those bills can be relatively seamless, that will only happen if you let your providers know of the change. If you have switched to a new health insurance plan, that plan will provide you with an ID card, usually within 30 days from the date they receive notice of your enrollment change. If you need services before you receive your new card, you will have to contact your plan. 

If you have just retired, there are a few things to keep in mind. For one, your premiums will be deducted from your annuity in 12 equal payments, instead of from your salary in 26 biweekly ones. For another, you will no longer be able to pay your FEHB premiums with pretax money, so even if those premiums were the same, your health benefits coverage will cost you more.