Mark S. Klein
Partner, Chairman of the Firm
Practices & Industries
Admissions
- New York
- New Jersey
- Florida
- U.S. Supreme Court
Education
State University College at Buffalo, B.S., summa cum laude
University at Buffalo School of Law, J.D., magna cum laude
Mark is Chairman of the Firm and concentrates his practice in New York State and New York City tax matters. He has more than 40 years of experience with federal, multistate, state and local taxation -- and may be best known for his public speaking on tax topics. Mark splits his time between the Firm's New York City and Buffalo offices.
Mark has represented numerous Fortune 500 companies in connection with corporate, withholding and sales tax audits as well as dozens of individuals who appear on the Forbes 400 list of wealthiest individuals in the United States. He has also been quoted in dozens of newspapers and periodicals, including The New York Times, The Wall Street Journal, Newsday, The Boston Globe and the Associated Press. Mark has appeared as a state tax expert on CNBC, CNN and other news outlets.
Mark taught courses in the Tax Certificate Program in the School of Management at the University of Buffalo on state taxation and tax practice and procedure. He is a member of The CPA Journal editorial review board and has written numerous books, articles and treatises on the subject of multistate taxation. Mark is the co-author of the ABA Sales & Use Tax Desk Book, CCH's New York Residency and Allocation Audit Handbook; New York Sales and Use Tax Answer Book, the New York State Bar Association's Contesting New York State Tax Assessments, 4th Edition; and CCH's New York Sales and Use Tax. Mark is also a contributor to numerous professional and industry-focused publications.
Honors
- Listed, Best Lawyers in America (Tax Law, Litigation and Controversy -Tax) 1995 - 2024
- Listed, New York Metro Super Lawyers (Tax) 2019 - 2023
- Listed, Upstate New York Super Lawyers (Tax) 2007 - 2023
- Listed, Best Lawyers in America "Lawyer of the Year" (Litigation and Controversy - Tax), 2021
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Listed, Buffalo Business First/Buffalo Law Journal’s Legal Elite of Western New York Legal Leader, 2018 - 2020
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Martindale-Hubbell, 1998-2022 – highest possible peer review rating in legal ability & ethical standards for 24 years
- Who's Who in American Law
In the News
- Bloomberg Law, July 10, 2023
- November 29, 2022
Press Releases
- September 22, 2023
- August 23, 2023
- August 17, 2023
- November 30, 2022
Publications
- Hodgson Russ LLP State & Local Tax Alert, July 6, 2023
- Hodgson Russ State and Local Tax Alert, May 5, 2023
- Hodgson Russ SALT Alert, January 3, 2023
Presentations & Events
- August 23, 2023
- Curtiss Hotel, Buffalo, NY, August 10, 2023
- 605 Third Avenue, New York, New York, June 21 - August 2, 2023
- July 20, 2023
- Aria Resort, Las Vegas, NV, June 8, 2023
- Palm Beach, Boca Raton, Miami, Sarasota, Naples, Florida, January 26, 2023 - February 24, 2023
- Long Island Marriott, December 15, 2022
- December 8, 2022
- November 30, 2022
- Crest Hollow Country Club, November 17 - November 18, 2022
- Washington Hilton –1919 Connecticut Avenue NW, Washington, DC 20009, November 1 - November 2, 2022
- September 28, 2022
- September 20 - September 21, 2022
- August 22, 2022
- August 17, 2022
- NYC and Park Ridge, NJ, June 15 - July 20, 2022
- Saratoga Springs, New York, June 28, 2022
- Las Vegas, Nevada, June 4 - June 9, 2022
- Manalapan/Palm Beach, Boca Raton, Sarasota and Naples, Florida, February and March 2022
- February 21, 2022
- December 9, 2021
- December 7, 2021
- December 6, 2021
- Long Island Marriott, Uniondale, NY, December 2, 2021
- November 16, 2021
- Washington Hilton, Washington D.C., November 15, 2021
- November 9, 2021
- Millennium Hotel Buffalo, November 5, 2021
- October 19, 2021
- Marriott Melville Long Island, August 25, 2021
- July 21, 2021
- June 2021
- March 25, 2021
- February 26, 2021
- February 9, 2021
- January 26, 2021
- January 12, 2021
- December 16, 2020
- December 3, 2020
- December 2, 2020
- December 1, 2020
- November 19, 2020
- November 16, 2020
- November 16, 2020
- November 6, 2020
- October 30, 2020
- August 26, 2020
- August 7, 2020
- Wednesdays, May 6 - June 17
- June 5, 2020
- Boca Raton, Fort Lauderdale, Naples, Manalapan, Miami, Sarasota, Florida, January and February 2020
- New York, NY, January 7, 2020
- Saddle Brook, NJ, December 18, 2019
- New York, NY, December 11, 2019
- Uniondale, NY, December 5, 2019
- Woodbury, NY, November 21, 2019
- Foundation for Accounting Education Learning Center, New York, NY, November 15, 2019
- Buffalo, NY, November 7, 2019
- November 6, 2019
- New York, NY, November 6, 2019
- New York, September 18, 2019
- New York, New York, August 20, 2019
- Understanding New York State Tax Issues of 2019The Harvard Club 35 W. 44th Street, New York, NY, June 12 - August 7, 2019
- New York, New York, June 21, 2019
- Las Vegas, Nevada, June 11, 2019
- Las Vegas, Nevada, June 11, 2019
- May 2, 2019
- Boca Raton, Fort Lauderdale, Naples, Manalapan, Sarasota, Florida, January and February 2019
- January 24, 2019
- December 19, 2018
- Mayfair Farms, 481 Eagle Rock Ave., West Orange, NJ 07052, December 13, 2018
- New Yorker Hotel, 34th Street & 8th Avenue, New York, NY 10001, December 12, 2018
- Saddle Brook Marriott, 138 New Pehle Ave., Saddle Brook, NJ 07663, December 5, 2018
- Uniondale, New York, November 29, 2018
- Woodbury, New York, November 14-15
- Buffalo, New York, November 9, 2018
- New York, New York, November 7, 2018
- November 30, 2018
- October 9, 2018
- New York, New York, October 9, 2018
- September 25, 2018
- Accountants Continuing Education– Mid-Year Tax Conference – NYS Tax UpdateNew York, New York, August 22, 2018
- Understanding New York State Tax Issues of 2018The Harvard Club 35 W. 44th Street, New York, NY, June 13 to August 1, 2018
- MGM Grand, Las Vegas, NV, June 9-14, 2018
- Palm Beach, Boca Raton and Naples, Florida, January, February & March 2018
- NYSSCPAs- Sid Kess WorkshopJanuary 31, 2018
- CPA Club of Bergen County- NY Tax UpdateJanuary 18, 2018
- CPA Club or Bergen County, Abandoned PropertySaddle Brook, New Jersey, January 18, 2018
- CPA Club of NJ- NY Tax UpdateJanuary 17, 2018
- CPA Club of New Jersey, NY Tax UpdateWest Orange, New Jersey, January 17, 2018
- Accountants' Continuing Education PresentationNew York, New York, January 4, 2018
- Accountants Continuing Education (ACE) NY Tax UpdateDecember 14, 2017
- November 29, 2017
- November 17, 2017
- November 15, 2017
- Understanding New York State Tax Issues of 2017The Harvard Club 35 W. 44th Street New York, NY, June 7 to August 2, 2017
- ACE: NY Tax UpdateNew Yorker Hotel, New York, November 10, 2016
- The Harvard Club, 35 West 44th Street, New York, NY 10036, November 2, 2016
- Hodgson Russ LLP, 1540 Broadway, 24th Floor, New York, NY 10036, October 27, 2016
- New York, NY, October 26, 2016
- New York, NY, August 24, 2016
- New York, NY, August 17, 2016
- AICPA Tax Strategies Conference: Residency and Domicile PlanningLas Vegas, NV, May 25, 2016
- AICPA Tax Strategies Conference: Nexus and ApportionmentLas Vegas, NV, May 24, 2016
- Foundation of Accounting Education Webcast: CorporateWall Street, NYC, February 9, 2016
- NYSSCPA Tri-State Conference: New York Tax UpdateJanuary 21, 2016
- Boca Raton, Naples, & Palm Beach Florida, January & February 2016
- CPA Club New York Tax UpdateNew Jersey, January 7, 2016
- ACE: New York Tax UpdateLong Island, NY, December 16, 2015
- Foundation of Accounting Education- Suffolk Chapter: New York Tax UpdateMelville, NY, December 12, 2015
- NCCPAP Tri-State: New York Tax UpdateTarrytown, NY, December 8, 2015
- NCCPAP Annual Tax Plenary Conference: New York Tax UpdateBaruch College, NY, December 8, 2015
- NJSCPA Multistate: New York Tax UpdateNew Jersey, December 3, 2015
- New Jersey Education Association Conference: New York Tax UpdateNew Jersey, December 2, 2015
- NYSSCPA West Chapter: New York Tax UpdateRye Brook, NY, December 1, 2015
- Long Island Tax Professionals Symposium: New York Tax UpdateWoodbury, NY, November 18, 2015
- NYSSCPA NYS Taxation Conference: New York Tax UpdateNew York Bar Association, NYC, November 10, 2015
- AICPA National Tax Conference: Audit AnalyticsWashington, DC, November 2, 2015
- UB Tax Institute: New York Tax UpdateBuffalo, NY, October 30, 2015
- ACE: New York Tax UpdateNew York, NY, October 28, 2015
- NYSSCPA Construction Conference: Sales Tax and ResidencyWall Street, NYC, October 21, 2015
- Estate Analysts of WNY: New York Tax UpdateBuffalo, NY, October 5, 2015
- 46th Annual Sid Kess Conference: New York Tax UpdateNew York, NY, September 10, 2015
- The Harvard Club, 35 W. 44th Street, New York, NY, Summer 2015
- Foundation of Accounting Education Webcast: ResidencyWall Street, NYC, July 23, 2015
- Summer 2015
- AICPA: Multistate RebroadcastNew York, NY, June 26, 2015
- Tax Roadshow: New York State UpdateLong Island, NY, June 17, 2015
- AICPA: Residency RebroadcastNew York, NY, June 16, 2015
- ISA Boston: New York State UpdateBoston, MA, June 12, 2015
- Contesting Tax AssessmentHarvard Club, NYC, June 10, 2015
- Foundation of Accounting Education Webcast: MultistateWall Street, NYC, June 8, 2015
- Leib Preis: New York Tax UpdateNew Jersey, June 2, 2015
- Boca Raton, FL, February 26, 2015
- Foundation of Accounting Education Webcast: ResidencyWall Street, NYC, February 4, 2015
- Florida, February 2015
- CPA Club: New York Tax UpdateNew Jersey, January 14, 2015
- NCCPAP 2014 Tri-State Seminar: New York Tax UpdateTarrytown, NY, December 16, 2014
- ACE: New York Tax UpdateNew York, NY, December 15, 2014
- Foundation of Accounting Education- Suffolk Chapter: New York Tax UpdateLong Island, NY, December 13, 2014
- ACE: New York Tax UpdateLong Island, NY, December 4, 2014
- NJSCPA: New York Tax UpdateEast Hanover, NJ, November 21, 2014
- NCCPAP: New York Tax UpdateWoodbury, NY, November 19, 2014
- Foundation for Accounting Education Annual Westchester Tax Conference: New York Tax UpdateArmonk, NY, November 10, 2014
- UB Tax Institute: New York Tax UpdateBuffalo, NY, November 7, 2014
- Foundation for Accounting Education Hospitality Conference: New York State UpdateNew York, NY, November 4, 2013
- AICPA: Residency and Sales TaxWashington, DC, November 3, 2014
- Foundation of Accounting Education Construction Conference: Sales TaxNew York, NY, October 22, 2014
- Foundation for Accounting Education Webinar: How to Handle an AuditNew York, NY, October 21, 2014
- Foundation for Accounting Education Webcast: How To Handle An AuditWall Street, NYC, October 21, 2014
- Bonadio Group: New York Tax UpdatePittsford, NY, October 17, 2014
- Legislative Changes and Residency UpdateUJA Federation, NYC, September 18, 2014
- Foundation for Accounting Education: New York Tax UpdateNew York, NY, July 16, 2014
- Foundation for Accounting Education: New York Tax UpdateNew York, NY, July 9, 2014
- Foundation of Accounting Education Webcast: Sales TaxNew York, NY, June 18, 2014
- June & July 2014
- Smart Pros: ResidencyNew York, NY, June 5, 2014
- Leib Preis Study Group: New York Tax UpdateNew Jersey, June 4, 2014
- Philanthropic Planning Group: Changing Your DomicileNYU Kimmel Center, NYC, May 21, 2014
- New York State Bar Association: Sales Tax DevelopmentsNYC- Cornell Club, April 29, 2014
- Foundation of Accounting Education WebcastWall Street, NYC, January 29, 2014
- Palm Beach & Naples, FL, January & February 2014
- New York, NY, January 23, 2014
- CPA Club of Bergen County: NY UpdateNew Jersey, January 22, 2014
- National Conference of CPA Practitioners: New York UpdateTarrytown, NY, December 17, 2013
- Foundation for Accounting Education Westchester Chapter Conference: New York UpdateArmonk, NY, December 13, 2013
- ACE: New York UpdateUniondale, NY, December 12, 2013
- Foundation for Accounting Education NYS Annual Tax Conference: Sale of a BusinessNew York, NY, December 10, 2013
- New York State Society of CPAs Nassau Chapter ConferenceUniondale, NY, December 7, 2013
- American Institute of CPAs webcast: New York UpdateNew York, NY, December 6, 2013
- Long Island Symposium: New York UpdateWppdbury, NY, Novemeber 20 & 21, 2013
- ACE: New York UpdateNew York, NY, November 12, 2013
- Buffalo Tax Institute: New York UpdateBuffalo, NY, November 7, 2013
- American Institute of CPAs National Tax Conference: Tax traps of Doing Business on the WebWashington, DC, November 5, 2013
- American Institute of CPAs National Tax Conference: Nuts and Bolts of Changing your ResidenceWashington, DC, November 5, 2013
- Foundation for Accounting Education Tax Plenary Conference: NYS Income TaxNew York, NY, October 30, 2013
- Foundation for Accounting Education Entertainment & Sports Committee: Personal Income TaxNew York, NY, October 29, 2013
- Bonadio Group: New York UpdateRochester, NY, October 25, 2013
- United Jewish Appeal Federation: New York UpdateNew York, NY, October 9, 2013
- Foundation for Accounting Education Construction Conference: New York UpdateNew York, NY, August 8, 2013
- Foundation for Accoutning Education CFO Conference: New York UpdateNew York, NY, July 17, 2013
- June & July 2013
- Leib Preis Tax Study Group: New York UpdateNew Jersey, June 11, 2013
- Estate Planning Council of Westchester County: Tax Update With Emphasis on DomicileWhite Plains, NY, June 5, 2013
- American Assocation of Attorney- Certified Public Accountants: Hot Topics in New York Tax EnforcementNew York, NY, June 4, 2013
- The Ayco Company: Multistate UpdateBoston, MA, June 3, 2013
- American Institute of CPAs: Multistate Tax (Individual & Business)Las Vegas, NV, May 21, 2013
- American Institute of CPAs: Best Tax Ideas PanelLas Vegas, NV, May 20, 2013
- New York State Bar Association 17th Annual NYS & NYC Tax Institute: New York State UpdateNew York, NY, May 7, 2013
- The CPA Club: New York State/ New York City UpdateWest Orange, NJ, February 6, 2013
- Toronto, ON, January 31, 2013
- ISA Meeting: New York UpdatePhoenix, AZ, January 24 & 25, 2013
- Palm Beach & Naples, FL, January & February 2013
- New York, NY, January 16, 2013
- PrimeGlobal: Nonresident Income TaxSan Diego, CA, January 7, 2013
- June & July 2012
- Morristown, NJ, June 5, 2012
- Palm Beach & Naples, FL, January & February 2012
- Buffalo, NY, July 19, 2011
- June & July 2011
- Palm Beach & Naples, FL, January & February 2011
- Buffalo, NY, July 22, 2010
- June & July 2010
- Uniondale, NY, January 27, 2010
- New York, NY, October 27, 2009
- July 16, 2009
- June & July 2009
- New York, NY, January 28, 2008