The number of U.S. physicians and other medical professionals prescribing electronically is expected to more than double in 2009 due to higher Medicare payments tied to the technology's use. However, only one in four physicians and other prescribers who are office based are e-prescribing, up from 74,000 in 2008. And through the end of August, only 110 million of the more than 3.7 billion prescriptions dispensed annually by U.S. retail pharmacies were sent electronically, according to data released by Surescripts.