USi Honored for Addressing Digital Divide Issues in Community; Housing Authority Communities Get Access, Equipment in Exemplary Program.

Business/Technology Editors

ANNAPOLIS, Md.--(BUSINESS WIRE)--March 21, 2000

USinternetworking, (Nasdaq:USIX), the leading Application Service Provider (ASP), was awarded a special commendation from Senator Barbara Mikulski (MD-D) for its initiative to provide computer equipment and training to the residents of the Housing Authority of the City of Annapolis (HACA). The initiative was developed to help address the growing disparity between those who have access to technology and those who don't.

The public/private partnership provides residents with access to three technology centers equipped with state-of-the-art computers, printers and high-speed Internet access. To further expand access and availability of computers, five residents per month, for one year, are receiving PC stations (including hardware, software, desk, chair, Internet access and a prepaid phone line) for in-home use. USi and HACA are also rolling out training, tutoring and mentoring programs.

"Since USi's inception, we have been dedicated to improving the communities where we work and live. The HACA project is a tangible example of this philosophy," said Christopher R. McCleary, Chairman and Chief Executive Officer of USi. "We are honored to receive this recognition of our community leadership, but the real credit goes to the families in the Annapolis Housing Authority community who are embracing the technology to better themselves."

Senator Mikulski serves on the Senate Health, Education, Labor and Pensions Committee and is the Ranking Democrat on the VA/HUD Appropriations Subcommittee.

About The Housing Authority of the City of Annapolis

The Housing Authority of the City of Annapolis (HACA) was established in 1937 to provide affordable, decent, safe and sanitary housing to low and moderate income persons. There are 1,104 units available for occupancy, ranging from 92 efficiency units to two 6-bedroom units. Funding for HACA is derived from dwelling rents and contributions from the Department of Housing and Urban Development (HUD).

About USinternetworking, Inc.

USinternetworking Inc. (NASDAQ:USIX) is the leading Application Service Provider delivering enterprise software as a service. The company's iMAP(SM) portfolio of service offerings delivers the rich functionality of leading software from Ariba, BroadVision, Lawson, Microsoft, Niku, PeopleSoft, Sagent, and Siebel as a continuously supported, flat rate monthly service enabling enterprises to rapidly and cost effectively deploy modular eBusiness functionality with secure global Internet connectivity. USi's AppHost service enables Independent Software Vendors to effectively provide their customers with their software products as Internet-based services.

Internet Managed Application Provider, iMAP, AppHost and PriorityPeering are service marks of USinternetworking, Inc. All other trademarks are the property of their respective owners. USi strategic partners and providers are publicly traded on Nasdaq under the symbols: BVSN, CSCO, MSFT, PSFT, SEBL, and SGNT.

Information in this release may involve expectations, beliefs, plans, intentions or strategies regarding the future. These forward-looking statements involve risks and uncertainties. All forward-looking statements included in this release are based upon information available to USinternetworking Inc. as of the date of the release, and we assume no obligation to update any such forward-looking statement. The statements in this release are not guarantees of future performance and actual results could differ materially from our current expectations. Numerous factors could cause or contribute to such differences. Some of the factors and risks associated with our business are discussed in the Company's registration statement on Form S-1 declared effective by the Securities and Exchange Commission ("SEC") on April 8, 1999, the Company's Form 10-Q filed with the SEC on November 15, 1999, and in our other reports filed from time to time with the SEC.