Officially, the area is designated by the Office of Management and Budget (OMB) as the Washington–Baltimore–Arlington, DC–MD–VA–WV–PA Combined Statistical Area. It is composed primarily of two major metropolitan statistical areas (MSA), the Washington–Arlington–Alexandria, DC–VA–MD–WV MSA and the Baltimore–Columbia–Towson, MD MSA. In addition, five other smaller urban areas not contiguous to the main urban area but having strong commuting ties with the main area are also included in the metropolitan area. These are: the Hagerstown–Martinsburg, MD–WV MSA, the Chambersburg–Waynesboro, PA MSA, the Winchester, VA–WV MSA, the California–Lexington Park, MD MSA, and the Easton, MD micropolitan statistical area (µSA).