In 1994 Jackie Koscelnik joined Walter DeForest to found the law firm of DeForest & Koscelnik, now DeForest Koscelnik Yokitis Skinner & Berardinelli. Jackie started her legal career as an associate with Reed Smith Shaw & McClay.

Jackie represents a variety of employers including manufacturing and industrial companies, television stations, hospitals and universities, in both federal and state courts as well as before government agencies such as the Equal Employment Opportunity Commission, the Office of Federal Contract Compliance Programs, the National Labor Relations Board, the Pennsylvania Human Relations Commission, and the City of Pittsburgh Commission on Human Relations. Her representation focuses primarily on employment and business-related matters, including employment discrimination, sexual harassment, wage & hour, unemployment compensation and union contract matters. Her practice includes advice on affirmative action, union avoidance, reasonable accommodation, hiring practices, personal services contracts, employee discipline and termination issues, and on compliance with the Americans With Disabilities Act and the Family and Medical Leave Act. She drafts comprehensive employee handbooks, human resources guidelines and affirmative action plans. She has been invited by employers on numerous occasions to speak to groups of employees and/or supervisors on topics ranging from union avoidance to sexual harassment.

For many years Jackie has provided an annual weekend of extensive employment law education to senior level broadcast managers and owners enrolled in the Broadcast Leadership Training program sponsored by the National Association of Broadcasters Education Foundation. Jackie served on the Editorial Review Board of The Pennsylvania Labor Letter, which was a monthly newsletter for Pennsylvania employers. She also taught Legal Research and Writing as an Adjunct Professor of Law at the Duquesne University School of Law.

Jackie graduated first in her class from the Duquesne University School of Law in 1990. In 1983 she received undergraduate degrees in biology and nursing from Allegheny College and the University of Rochester, respectively. Prior to becoming a lawyer, Jackie was an intensive care nurse at Allegheny General Hospital in Pittsburgh.

Jackie is admitted to practice law in Pennsylvania and West Virginia. She has been named in the book The Best Lawyers in America for over ten years.