Beyond the SFRA...
For the FRZ, you have to call in person, for anyone wanting to go FURTHER in and land at one of the "DC-3" general aviation airports.
Worth the hassle - College Park Airport is a gem - fantastic FBO and GA Museum, good runway and facilities and less-expensive fuel.
Additionally, the METRO is across the street taking you anywhere in DC. (I used to be BASED there)
Mike N714AJ