Because you don't own the entire building, insuring a condominium or co-op is different than insuring a typical home. In addition to the master policy, there is a special form of homeowners insurance designed specifically for condo and co-op owners. In the insurance world, this is called HO-6.
HO-6 policies protect your personal property from losses caused by perils named in the policy. These typically include fire, lightning, storm, explosion, riot, aircraft, smoke, vandalism, theft, broken glass, and volcanic eruption. If a loss is caused by anything other than the named perils, it is not covered.
HO-6 typically covers improvements, additions, private balconies, private entranceways, private garages, and other property that is your insurance responsibility under your condo association's guidelines. HO-6 policies also provide liability coverage similar to that found in a standard homeowners policy. If you are found responsible for personal injury or property damage to another person, your HO-6 policy would typically cover you.
The master policy maintained by your condo association is also a vital part of your total insurance coverage. This policy typically covers the common areas you share with other tenants, including the roof, stairways, elevators, and basement. It may cover the structure of individual units as they were originally built, and may cover fixtures in the individual units.
It is important to know exactly what the master policy covers, so that you can purchase appropriate individual coverage for your unit and personal property. For instance, if the master policy doesn't cover fixtures in the individual units, you'll want to make sure that your brass faucets and crystal chandeliers are included in your HO-6 policy.
If you live in a coastal area or your region is prone to earthquakes, you also might want to consider purchasing separate hurricane or earthquake insurance. Standard HO-6 coverage does not cover damage caused by these events.