The program committee is delighted to invite you to the 9th ACM Workshop on Mobility in the Evolving Internet Architecture (MobiArch) 2014. The workshop will be held in Maui, Hawaii, on September 11, 2014,. This year, MobiArch is co-located with MobiCom 2014. Aim and Scope With recent developments in wireless access, sensor, and mobile device technologies, the mobility of users, terminals, and networks has become an indispensable component of today's Internet vision. Wireless access devices by far outnumber stationary Internet hosts and an increasing share of traffic traverses at least one wireless link. These trends can be expected to continue in the near future and call for a reexamination of the architectural design of the current and future internets. With recent advances in technologies for wireless access (such as WiFi, 3G, and 4G) and mobile devices (such as smartphones, netbooks, and tablets), mobility has become a fundamental characteristic of today's Internet. Yet, basic architectural issues related to mobility such as efficient mobility management, the locator-identifier split, multi-homing, security, and various operational, deployment concerns are still not fully explored. Moreover, the Internet architecture itself, its end-to-end principles and business models require rethinking due to the massive penetration of mobility into the Internet. MobiArch 2013 welcomes submissions from both researchers and practitioners that explore challenges or advances in architectures, protocols, and technologies to address mobility challenges in the current Internet or in future clean-slate Internets. We especially welcome position papers that describe highly original ideas, discuss new directions, or generate insightful discussion at the workshop.