Sion & Associates

Attorneys at Law

Advocators, Litigators, Educators

Concentrating on Workers' Compensation Defense

About Us

We are a community of professionals who enjoy our work, our clients, and our associations with each other.

Founded in 1998, our office concentrates on defending California employers in workers' compensation and related labor law matters. Located in Century City, California, we provide legal services to major corporations and other clients headquartered throughout the United States. We are proud of having distinguished our firm by working with our clients to assist in implementing safety prevention measures, investigating industrial injury and discrimination claims, reviewing medical protocol, and reviewing Return to Work policies. We emphasize an integrated approach to resolving industrial injury claims by requesting that employers and insurance carriers actively participate in the defense of claims, in an effort to reduce overall costs.

Our practice provides detailed and thorough representation regarding all aspects of industrial injury claims, from investigation to Trial. Our representation covers claims of orthopedic and psychiatric injuries, chemical and toxic exposure, discrimination actions under Labor Code Section 132a, as well as allegations of Serious and Willful violations. A staple of our practice is to apply civil litigation skills in the workers' compensation arena. Thus our Attorneys are trained to have a comprehensive understanding of California labor, litigation and other laws and regulations applicable to our business. We are solely dedicated to representing the employer side of workers' compensation matters. We actively track legislation pending before the California State Assembly and before the federal government. We issue periodic legislative updates to our clients, and our Attorneys are available to present seminars on workers' compensation and legislative issues.


Steven Mark Sion

Founder & Principal

Mr. Sion is a native of Providence, R.I., and is a past member of the Rhode Island State and District of Columbia Bar Associations. Mr. Sion joined the California Bar in 1991, and has practiced law in California since that time.

Mr. Sion studied at Providence College, the University of Fribourg (Switzerland) and New England School of Law. In Rhode Island, he worked in both civil litigation and workers’ compensation.

Prior to founding his own business in 1998, Mr. Sion was an Associate respectively at the law firms of Gilbert, Kelly, Crawley & Jennett, and Seyfarth, Shaw, Fairweather & Geraldson.

In addition to his practice, Mr. Sion actively pursues legislative advocacy on behalf of employers, and was thrice elected to annual terms as Chair of the Legislative Affairs Committee on the Board of Directors of the Professionals In Human Resources Association (PIHRA).

Daniel D. Davis

Senior Associate

Daniel D. Davis joined Sion & Associates in October 2017. Daniel received his Juris Doctor Degree from Southwestern Law School in Los Angeles, CA where he also served as President of the Law Student Association. He graduated with Honors from Georgia State University in Atlanta, Georgia where he received a B.A. in Political Science. Prior to joining Sion & Associates, Mr. Davis worked at an employment litigation firm where he assisted in all aspects of employment litigation cases from discovery to trial. Mr. Davis now enjoys devoting his time and efforts to the representation of employers in defending their claims in the field of workers’ compensation.

Rhiannon Hunsberger

Of Counsel

Rhiannon Hunsberger earned her Juris Doctor through Southwestern Law School’s accelerated two-year program in 2017 and was admitted to the California Bar in 2018. Prior to joining the Sion team, Ms. Hunsberger served as a Sergeant in the California Army National Guard Judge Advocate General's Corps for 13 years. Currently, she is a Loyola Law School Master of Laws candidate.

Phil Billow


Phil Billow received his Juris Doctor degree from the University of Wisconsin Law School in Madison, Wisconsin with a distinction in Appellate Advocacy. He received his B.A. in Political Science from The Ohio State University. Prior to practicing employment defense at Sion & Associates, Mr. Billow worked for the City Attorney’s Office of San Francisco in their general litigation practice. Throughout law school, he gained practical litigation experience as a student attorney in consumer protection cases, winning cases for victims of harassment at the state and appellate level.

Jennifer Gabbay

Associate Attorney

Jennifer P. Gabbay received her Juris Doctor from Southwestern Law School in Los Angeles and was admitted to the California Bar in 2011. While at Southwestern, Ms. Gabbay studied abroad in Israel at Bal-Illan School of Law and in Argentina at Universidad de Buenos Aires. She received her B.A. in Political Theory and a Minor in Philosophy from the University of California San Diego, where she graduated Magna Cum Laude with Honors. Prior to joining Sion & Associates, Ms. Gabbay was an Associate in Workers’ Compensation firms, including Rose, Klein and Marias. Ms. Gabbay has devoted her career to the field of Workers’ Compensation and has experience in all aspects of Workers’ Compensation practice before the WCAB.

Krystel Sanford


Krystel Sanford received her Juris Doctor from the University of San Francisco School of Law and her B.S. in Jurisprudence and Political Science from Montclair State University, Montclair, New Jersey. Prior to working for Sion & Associates, she worked for the Department of Labor, Office of Federal Contract Compliance Programs, for seven years, before going to law school. Upon graduation, and prior to working at Sion & Associates, she worked as a paralegal for an employment and personal injury firm and in Public Relations.

Administrative Team

If you are interested in joining our team, please send a cover letter and resume to

Firm Employer Guides & Presentations

An Employer's Guide to Return to Work Issues in California

Reform of the Reform Legislation: A Discussion of Senate Bill 863

Effective Workers' Compensation Claims Management: Minimizing Costs

The Spinal Surgery Guide

A New Day in California Workers' Compensation Laws


Sion & Associates

Attorneys at Law

Contact us today at
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Our Addresses

1880 Century Park East, Suite 617
Los Angeles, CA 90067
(310) 858-7500