When they say they will allow employees to purchase insurance for 18 months that sounds like it is COBRA. What they are saying doesn't make a lot of sense otherwise. It could also be offered under a state law similar to COBRA.
How big is the employer? What state are you in? Is the employer a church related organization, university or the federal government? If so, they may be exempt from COBRA.
You want to be sure that it is COBRA and not an individual conversion plan you would be buying because once you are out of the group market you lose your HIPAA rights.
Here are the HIPAA rules:
No matter where you live in the U.S., if you are federally eligible you are guaranteed the right to buy individual coverage of some kind with no pre-existing condition exclusion periods. To be federally eligible, you must meet all of the following:
´ You must have had 18 months of continuous creditable coverage, at least the last day of which was under a group health plan.
´ You also must have used up any COBRA or state continuation coverage for which you were eligible.
´ You must not be eligible for Medicare, Medicaid, or a group health plan.
´ You must not have health insurance. (Note, however, if you know your group coverage is about to end, you can apply for coverage for which you will be federally eligible.)
´ You must apply for health insurance for which you are federally eligible within 63 days of losing your prior coverage.
Federal eligibility ends when you enroll in an individual plan, because the last day of your continuous health coverage must have been in a group plan. You can become federally eligible again by maintaining continuous coverage and rejoining a group health plan.