John Nathaniel Kogan

John Nathaniel Kogan, beloved husband, father, grandfather, brother, colleague, and friend, died on August 23, 2026, at the age of 86, after living with Parkinson’s disease for 25 years.

John was born on January 15, 1940, to Jeanne and Robert Kogan and was the eldest of five children. Growing up on Manhattan’s Upper East Side, he was independent, outspoken and endlessly curious, always looking for the next adventure.

That sense of adventure was matched by an exceptional intellect. After attending P.S. 6 on the Upper East Side, John earned a place at the Bronx High School of Science. He then boarded an Amtrak train with a single suitcase and his bicycle to enroll at the Massachusetts Institute of Technology, where he earned his undergraduate degree in Electrical Engineering with honors. He later attended the Sloan School of Management.

John spent more than four decades at Andersen Consulting, where his combination of analytical brilliance, leadership and mentorship skills, and ability to problem solve earned him the respect of his colleagues and clients. Among his many professional accomplishments, he led the firm’s global consulting practice for the Y2K transition, traveling around the world to tackle an enormous and unprecedented technological challenge with the doggedness and determination that were hallmarks of his character.

John also believed strongly in helping others. As CEO of SCORE, he helped small-business owners navigate the challenges of entrepreneurship, including developing business plans and building the skills and strategies needed to succeed.

For 25 years, John faced the challenges of Parkinson’s disease with extraordinary resilience, grit and grace. He defied expectations throughout the course of the disease, continuing to pursue the activities and interests he loved and refusing to give up. His determination and optimism remained undiminished until just days before his death.

John had a lifelong love of sports(diagramming over 300 baseball games in parks throughout the country), travel, cycling, photography, music and comedy. He traveled to 108 countries, bringing to each journey his characteristic curiosity and enthusiasm. He could be equally passionate about a bicycle ride, a photograph, a meal or a good joke. He had an encyclopedic memory and served as the household Chat GPT.

But above all else, John was devoted to his family.

He was married for 64 years to his beloved wife, Ann Gordon Kogan. Together they built a life filled with family, travel, laughter and love. He was the proud father of two daughters, Suzanne Kogan Yearley, (Andrew Yearley,) and Laura Kogan Tichner, (Jerome Tichner.)

His grandchildren—Alexander Yearley, (Sydney); Campbell Yearley, (engaged to Josh Wasserman;) Marin Yearley; Nicole Tichner; and Hailey Tichner—were a tremendous source of pride and joy.

John is also survived by his sisters Nan Rydzy, Jill Blake and Victoria Murphy. He was predeceased by his brother, Bruce Kogan.

To those who knew him, John was brilliant, persistent and, when he believed something mattered, nearly impossible to dissuade. He was also deeply loving, generous with his time and always willing to help solve a problem. John, your curiosity, humor, determination, and love of life will live forever in the hearts of those who were fortunate to know you.

A memorial service will be held at Levine Chapels, 470 Harvard Street, Brookline, on Thursday, August 27, at 11:00 a.m. Livestream viewing available using the following link: www.tinyurl.com/JohnKogan

In lieu of flowers, donations may be made in John’s memory to The Michael J. Fox Foundation for Parkinson’s Research at https://give.michaeljfox.org/campaign/754698/donate .