After graduating in 1990, he attended the University of Colorado at Boulder as a ski racer but never finished the final semester of his BA degree course in economics.

Hamilton acted as a scout in individual time trials, riding as hard as possible to provide time-split comparisons for Armstrong.

Hamilton fractured a shoulder in a crash in the 2002 Giro d'Italia but still managed to win stage 14 and finish second overall, under 2 minutes behind race winner Paolo Savoldelli.

Instead of withdrawing from the race, he stayed to finish the tour, and exceeded everyone's expectations when he was able to follow and attack Armstrong up Alpe d'Huez on stage 8.

Later, he rode one of the Tour's most memorable feats, winning stage 16 with a 142 km solo breakaway, gaining two minutes over the field.

Furthermore, he placed 2nd in the 2004 Dauphine Libere, beating Armstrong up the Mont Ventoux time trial which promoted him to one of the Tour de France favorites.

[6] In 2019, Hamilton joined Black Swift Group, LLC, an investment advisor and money manager based in Boulder, Colorado.

[7] At the 2004 Summer Olympics in Athens, Hamilton won the gold medal in the men's individual time trial.

[9] In the Vuelta a España, he won the stage 9 time trial on September 11, 2004, but left the race six days later, citing stomach problems.

He was told by the Union Cycliste Internationale (UCI) on September 13, 2004 that his two samples from two days earlier showed a "foreign blood population.

[13] On April 18, 2005 Hamilton was sanctioned by the United States Anti-Doping Agency and received a two-year suspension,[14] the maximum sentence for a first offense.

[15] Hamilton claimed the UCI-sanctioned test was insufficiently validated (and may have returned a false positive result) and that some of the agencies involved had concealed documents that would support his case.

[16][17] On May 20, 2011, he also made the confession in an email to friends and family after a taping of the TV news show 60 Minutes, during which he also implicated Lance Armstrong in the doping scandal.

[18][19] Hamilton then voluntarily surrendered the gold medal he won at the 2004 Summer Olympics to the United States Anti-Doping Agency, which said it would continue its joint investigative work with the IOC.

[21][22] On June 18, 2006, the Madrid daily El País alleged that the Spanish civil guard investigation of doping in Spanish professional sport, "Operación Puerto", had found that Hamilton paid more than US$50,000 to Dr. Eufemiano Fuentes between 2002 and 2004 to plan and administer his use of performance-enhancing erythropoietin (EPO), growth hormone treatment, blood doping, and masking agents.

[23] El País charged that Hamilton's 2003 win of Liège–Bastogne–Liège came days after a "double" blood transfusion planned by Fuentes.

On June 26, 2006, Hamilton stated on his website: "I was very upset to read the accusations against me and to see my name associated with the Operación Puerto investigation in Spain.

The next day, August 20, 2006, the Belgian Dutch language Het Laatste Nieuws newspaper published more details of Hamilton's doping diary.

[25] On September 14, 2006, USA Cycling announced information from the UCI "regarding Tyler Hamilton and his alleged involvement in 'Operación Puerto' along with a request to move forward with disciplinary action."

[26] On April 30, 2007, La Gazzetta dello Sport published allegations that Spanish authorities had completed a second dossier on Operation Puerto, 6000 pages long and naming 49 cyclists.

[30] In September 2007, Tyler competed at the US national championship in Greenville, SC, coming sixth in the time trial and 12th in the road race.

Hamilton did not ride in the team's season-opening Tour of California because of that race's rules against riders involved in doping investigations.

Wearing his Rock Racing gear, Tyler Hamilton finished second of approximately 60 category one and two riders March 9, 2008 at a collegiate criterium in Denver's City Park.

[37] On September 5, 2012, Random House (Bantam Books) published Hamilton's memoir The Secret Race: Inside the Hidden World of the Tour de France: Doping, Cover-ups, and Winning at All Costs, coauthored with American writer Daniel Coyle.

He then recounts his years on the Phonak Team when he tested positive during the Vuelta a España to an alleged homologous blood transfusion.

His career in shambles, he raced for lesser teams after his suspension, tested positive for DHEA (in an OTC herbal anti-depressant) and retired.