Company's can impose a six month pre-ex clause which can be waived for having prior creditable coverage without a break in coverage of 62 days for an individual plan or 180 days for group to group coverage. A formulary is a list of drugs approved and paid for by the insurance company.
Formularies are an attempt by the industry to control the spiraling costs of prescription drugs.
All formulary lists are to be made available to the subscriber. If a particular drug is not on the insurance company's list, the company may not pay for its' costs. You may secure a likedrug that is on the list with the insurance company paying for it, or in some cases, paying an additional amount.