No. A standard landlord policy excludes flood damage the same way a homeowners policy does. Flood is written separately, either through the National Flood Insurance Program or a private flood carrier, and it has to be added on purpose. If a rental property has never had a flood policy, there's a good chance the owner doesn't know that gap exists until a claim gets denied.
Insurers define flood narrowly: water that rises from the ground up, from a river overflowing, a storm surge, heavy rain pooling and entering the property from outside, or a mudslide. That's different from water damage caused by a burst pipe, a roof leak, or an overflowing bathtub inside the unit, all of which a standard landlord policy typically does cover. The distinction matters because tenants and owners both tend to use "flood" to describe any water damage, and the source is what determines whether a claim gets paid.
A tenant who loses their belongings to a flood, or a unit that sits uninhabitable for months during repairs, becomes the owner's problem in a way it doesn't for a primary residence. Loss of rent coverage on a landlord policy activates for a covered water damage claim, not for something the policy excludes outright. Without a separate flood policy, an owner who floods is repairing the building out of pocket while still covering the mortgage with no rent coming in.
Flood maps set the requirement for a mortgage lender, not the actual risk. A large share of flood claims come from properties outside the mapped high-risk zones, and rates for moderate- or low-risk properties are usually inexpensive relative to the exposure. A property outside a mapped zone can still flood. It's just not required to carry the coverage.
Flood insurance is a separate policy that sits alongside the landlord policy, not an endorsement added to it. It can come through the NFIP or through a private flood carrier, and pricing and terms vary by location, elevation, and construction. The application runs through the same agent who handles the property policy.
Only if the property sits in a federally designated high-risk flood zone and carries a federally backed mortgage. Otherwise it's optional, though the exposure exists regardless of the zone.
Only if the tenant's own renters policy includes flood coverage, which most standard renters policies don't carry by default. That's a separate conversation between the tenant and their insurer.
NFIP policies typically have a 30-day waiting period before coverage starts, so it isn't something to add the week a storm is forecast. Some private flood carriers offer shorter waiting periods.
Yes. Flood insurance can be added at any point. It doesn't have to line up with the landlord policy's renewal date.
Related reading:
Insurance for Landlords With 1-3 Rental Properties
Vacant Rental Property Insurance
Umbrella Insurance for Landlords With Multiple Properties
— Aaron