A coverage can be reactivated if it was inadvertently closed. However, reactivating a coverage does impact billing. You may want to read the differences between reactivating a coverage and incepting a new coverage to determine which approach you want to take.
Reactivate is used when coverage has been terminated accidentally and coverage (and therefore billing) should have been continuous. For example, if coverage was terminated effective 10/1/2006 and reactivated 1/1/2007, the billing engine will go back to 10/1/2006 and bill for the unbilled periods in-between.
You should incept a new coverage if you want coverage to start billing from the new inception date. This is used if there was a gap in coverage and therefore there will be a gap in billing. For example, if coverage was terminated effective 10/1/2006 and you want to re-start the billing from 1/1/2007. Leave the old coverage as terminated. And incept a new coverage starting from 1/1/2007.
CBA Concepts: Coverage