In 1995, the GRG added the GRG.org website, and in 1998 began tracking the world's oldest validated living people.
The group was co-founded by L. Stephen Coles who is the Director and Treasurer of the Supercentenarian Research Foundation.  The other co-founder was Steven M. Kaye. Editions of the Guinness World Records through the year 2008 indicate that the the Gerontology Research Group is used as its authority for its "World's Oldest Living People" category, which the group verifies using birth and marriage certificates.
The New York Times wrote that the GRG has been recognized as "an authority on the matter" of verifying supercentenarians. The group started as an organization to investigate the limits of life spans in all mammalian species, and around 1998-1999 they started a committee to investigate claims to find out who was the oldest person at any point in time.
As of 9 June 2016, the organization is monitoring 49 people whom they have validated as living supercentenarians, of whom 47 are female and 2 are male. This does not include additional pending claims under investigation.
Current membership, which is over 500 persons, in the GRG includes:
- GRG Executive Director (2014-present) Johnny Adams; GRG system operator, business administator; GRG member from 2000
- Robert Young, Director, GRG Supercentenarian Research and Database Division (2015-), M.A., M.A., USA; GRG member from 1999
- Dr. Aubrey DeGrey, founder of SENS, USA-UK
- Hubert Warner
- Dr. Leonid Gavrilov (University of Chicago)
- Stan Primmer, M.A., USA
- Dr. Andrew Holmes, UK
- Dr. Luc de Lay, France
- Chris Law, M.A., UK
- Waclaw Jan Kroczek, DMD., Poland
- Dr. Harold Katcher, USA
- Mark Muir, USA
- Dr. Leonard Hayflick
- Marco Wikkerink, M.A., Netherlands
- Dr. George Church, USA
- Ricardo Pereira Lago, Brazil
- Tiago José Soares, Brazil
- List of the verified oldest people
- Longevity Claims
- Longevity myths
- Oldest People
- Extreme longevity tracking
- Kaye, Steven M. "General Concepts for Directions to Proceed with the 21st Century Biotechnology Group.". Joint Venture Partners. Retrieved 2007-10-31.
Much of the philosophy and technological developments described above, have come from the doctors and scientists participating in the Gerontological Research Group in Los Angeles. Gerontological Research, co-founded in 1992 by Steven M. Kaye, MD and Stephen Coles, MD, PhD., has become a "Rand Corporation" think tank for life extension research and development. The JVP Venture Fund Biotechnology Group has full access to the world’s most advanced thinking, and visionary medical scientists.
- "Odds of reaching 100 get better.". Pittsburgh Tribune Review. June 1, 2006.
... according to The Gerontology Research Group, a nonprofit volunteer organization ...Check date values in:
- "Research group tracks oldest-living people.". Daily Bruin. June 10, 2004. Retrieved 2007-10-31.
They are searching for an alternate route to immortality other than the fountain of youth. ... The group works closely with the Guinness Book of World Records and is now considered the primary source for verifying the world’s oldest person for the annual records’book. ... Coles added that about a year ago, the Guinness Book began to recognize the group as the primary source for verifying the ages of people.Check date values in:
- "The 100+ club". BBC. 2 September 2005. Retrieved 2007-10-31.
The term applies to anyone older than 110 and, according to the US Gerontology Research Group, there are 68 supercentenarians in the world today. None of them were born in the UK - Ms d'Abreu was born in India.Check date values in:
- "One of oldest Portuguese women, 110, dies.". Modesto Bee. November 9, 2007. Retrieved 2007-10-31.
... according to the Gerontology Research Group. Mrs. Sanders spent the last decade of her life at the La Sierra Care Center in Merced, ...Check date values in:
- "Supercentenarian Research Foundation". Gerontology Research Group. http://www.grg.org/. Retrieved 2007-10-31. "L. Stephen Coles, M.D., Ph.D., Director and Treasurer of the Supercentenarian Research Foundation"
- "Researchers Work to Crack Code of Long Life". Web MD. Retrieved 2007-10-31.
People don't live to be 110 "because they don't age; it's a fortuitous, genetic roll of the dice, so there is not an intervention available to people who are still alive," says L. Stephen Coles, MD, PhD, a gerontologist with the Los Angeles Gerontology Research Group at UCLA.
- "Guinness World Records 2008". 2008. pp. p. 67. ISBN 1-904994-19-9.
- Zaslow, Jeffrey (February 28, 2005). "Gerontology sleuths search for 'supercentenarians'". Wall Street Journal. Pittsburgh Post-Gazette. Retrieved 2007-10-31.
Her ripe old age was "a falsehood perpetrated by the tourism industry there," says GRG co-founder L. Stephen Coles, a physician and stem-cell researcher at UCLA's David Geffen School of Medicine, where GRG is based. GRG counts just 12 undisputed cases of people ever reaching 115. ... The 14-year-old GRG, which the Guinness World Records Book now relies on to confirm longevity records. ...Check date values in:
- "Researchers are studying what causes some people -- such as two OC...". Orange County Register. August 3, 2004.
Coles is co-founder of the Los Angeles Gerontology Research Group, which verifies supercentenarian ages for Guinness world Records using birth and marriage ...Check date values in:
- "In Connecticut, World's Oldest Woman Dies at 114.". New York Times. January 30, 2007. Retrieved 2007-11-16.
In the last month alone, the title of oldest person has changed hands three times, according to the Gerontology Research Group, an authority on the matter. 'The Guinness Book of World Records will not be able to keep up,' said Dr. L. Stephen Coles of the University of California, Los Angeles, the executive director of the group. 'This has been a pretty volatile time. Usually we’ve had a more stable No. 1 position.'Check date values in: