Nashville, Tenn., (May 28, 2026) – Bass, Berry & Sims is pleased to announce the addition of four new attorneys as part of the firm’s strategic growth plan. Joining the firm as counsel is Christian Mahre, along with attorneys Stefan R. Kostas, Stephanie Allen O’Hara, and Justin K. Powers.
These four new attorneys are the latest additions during a period of growth for Bass, Berry & Sims in line with an in-depth strategic assessment completed last year. Since the beginning of 2025, the firm has added more than 40 lateral attorneys nationally, including eight members. The firm also recently opened its Chicago office with the addition of partners from Reed Smith LLP.
“The addition of these four lateral hires marks another important step in the firm’s strategic growth for our clients throughout the country,” said Todd Rolapp, managing partner of Bass, Berry & Sims. “Each attorney brings specialized experience that complements our existing strengths and supports our investment in these practice areas. We’re excited to continue building a team that is both highly collaborative and deeply aligned with our clients’ evolving needs.”
Christian Mahre
Christian Mahre joins as a Counsel in Nashville. He advises private equity sponsors and both public and private companies on a full spectrum of mergers and acquisitions, private equity transactions, and other complex corporate matters. Mahre represents clients across the energy, infrastructure, industrials, and technology sectors, guiding them through strategic transactions that include acquisitions, divestitures, preferred equity investments, joint ventures, and large‑scale corporate reorganizations.
Prior to joining Bass, Berry & Sims, Mahre was a corporate partner at Kirkland & Ellis LLP. Before entering private practice, he served as a Captain in the U.S. Army. As an infantry officer, over the course of two combat deployments to Afghanistan he commanded an air assault rifle platoon and an infantry company. Mahre earned his law degree from Georgetown University Law Center (2019) and holds a Bachelor of Science from the United States Military Academy at West Point (2008).
* Christian Mahre is licensed to practice in Texas. He is licensed in Tennessee pursuant to Tenn. Sup. Ct. R. 7 Sec. 10.07
Stefan R. Kostas
Stefan Kostas joins as an Associate in Nashville. He counsels clients on corporate issues, including mergers and acquisitions and other strategic transactions. In addition, he represents private equity firms and portfolio companies in various transactions.
Before joining Bass, Berry & Sims, Kostas was an associate at Baker, Donelson, Bearman, Caldwell & Berkowitz P.C. He earned a law degree from the University of Tennessee College of Law (2022) and dual undergraduate degrees from the University of Florida (2019).
Stephanie Allen O’Hara
Stephanie O’Hara joins as a Public Finance Attorney in Knoxville, Tennessee. She has more than 15 years of experience providing counsel to governmental entities, municipal officials, and public agencies. O’Hara advises clients related to governance, contracts, regulatory compliance, ordinance drafting, and strategic advisory work.
Prior to joining Bass, Berry & Sims, O’Hara worked at the University of Tennessee’s Municipal Technical Advisory Service. She earned a law degree (2007), Master of Business Administration (2005), and Bachelor of Science in Business Administration (2003) from the University of Tennessee. After law school, she served as a judicial clerk with Justice Sharon G. Lee at the Tennessee Supreme Court and the Tennessee Court of Appeals.
Justin K. Powers
Justin Powers joins as an Associate in Nashville. He represents regional and national developers, buyers, sellers, landlords, and tenants on a range of commercial real estate transactions. His practice involves advising clients across the retail, healthcare, industrial, multifamily, office, and mixed-use assets sectors.
Before joining Bass, Berry & Sims, Powers was an associate at Chambliss, Bahner & Stophel, P.C. in Chattanooga, Tennessee. He earned a law degree from Belmont University College of Law (2021) and an undergraduate degree from Rhodes College (2018).
About Bass, Berry & Sims PLC
Bass, Berry & Sims is an independent, nationally recognized law firm dedicated to helping clients go confidently through complex legal challenges. We deliver high-caliber counsel and exceptional service to leading middle market companies across industry sectors, with particular focus in the healthcare and private equity industries. For over a century, our team has partnered with clients across the country on sophisticated transactions, significant litigation and investigations, and international regulatory matters. We collaborate seamlessly with deep experience across practice areas, industries, and geographies to provide innovative, business-focused solutions that create measurable value. For more information, visit www.bassberry.com.