Pacific Retirement Services climbed five spots to No. 12 in the eighth-annual LeadingAge-Ziegler 100, an annual listing of the largest nonprofit, multi-site senior living organizations.

Pacific Retirement Services climbed five spots to No. 12 in the eighth-annual LeadingAge-Ziegler 100, an annual listing of the largest nonprofit, multi-site senior living organizations.

The Medford-based company has risen from No. 28 in 2007 to No. 17 in 2010. With the opening of Mirabella Portland, a 30-story retirement community that opened in September 2010 in the South Waterfront District, PRS now has 2,878 total units — up 281 units from last year.

The parent company of Rogue Valley Manor operates 10 affordable senior housing communities in the greater Southern Oregon area: four in Medford, two in Grants Pass, and one each in Ashland, Central Point, Eagle Point and Klamath Falls.

The list ranked the largest providers by the total number of units as of Dec. 31, 2010.