Ms. Koster us a member of the Lehigh Valley Hospital–Pocono Board of Directors. She is President and Chief Executive Officer of Fitzmaurice Community Services, Inc., a nonprofit corporation that provides a full continuum of services for persons with intellectual disabilities, autism and behavioral health disabilities since 1975. Services include community residences, family support, vocational rehabilitation and psychiatric treatment. 

Ms. Koster has served as past President of the Northeast Providers Association, Pocono Providers Association, and Housing Solutions of Monroe County. She has served as Chair of the Greater Pocono Chamber of Commerce, Chair of Leadership Pocono, Friends of Eastern Monroe Public Library Board, Monroe County Historical Society Board, Pocono Flute Society Board. She is an Athena award recipient. 

Other accomplishments of Ms. Koster include a partnership with Northampton Community College and the development of a continued education program for individuals in the human services field to earn a certification as a professional in direct care, development of the Local Consumer Advocacy Group, and ClearView Clinical Services, Inc.

Ms. Koster is a graduate of East Stroudsburg University. Prior to 1975, she was a teacher in the New Jersey school system. She currently resides in East Stroudsburg with her husband, Albert.