Essential Air Service Modernization Act of 2003 - Increases the authorization of appropriations to carry out the essential air service program.
Requires the Secretary to: (1) notify an affected community at least 90 days before the basic essential service to that community is terminated: (2) facilitate and assist in negotiations between major and national air carriers and carriers that provide essential air service in order to determine equitable joint fares; (3) establish an alternate essential air service program which would provide compensation directly to local governments, instead of to air carriers, to use to obtain air service, to obtain surface transportation to and from air hubs, or to participate with other local governments in providing regional transportation services to airports; and (4) pay $5,000 to local governments to promote public use of air service or transportation for which compensation is received under the program.