The Insurance Binder lists the coverage amount as "Specified Additional Amounts of Insurance" instead of RCV. The agent is saying that they are the same thing. Does anyone have any experience or knowledge about this? Can we rely on that amount when determining the flood coverage amount required?

Is this a NFIP policy? Binders are worthless as proof of insurance for a NFIP policy. An agent is not authorized to bind NFIP insurance as it can only be issued by the NFIP and it is not issued from their company. You need a declaration page or an application with proof of payment. A declaration page for a NFIP policy must contain specific information and RCV is one of them.

Sorry I should have been more clear. This is the hazard insurance binder; we are trying to determine the RCV so we can calculate the required coverage amount for flood.

Then the definition of what is listed on an individual company's binder is going to be totally based on what the company requires and how it is defined and it also appears to be potentially related to State insurance law. Personally, I have no idea what "Specified Additional Amounts of Insurance" may mean. You would have to read the policy to determine what it means.