The season was profoundly affected by the death of two-time Cup Series champion Kyle Busch on May 21, who succumbed to sepsis caused by pneumonia. Busch became the first active full-time driver to pass away during a season since Dale Earnhardt's death in 2001. His passing cast a shadow over the Coca-Cola 600 weekend and prompted tributes from across the motorsport community.
NASCAR introduced a new Chevrolet ZL1 body style for 2026, based on the Carbon Performance Package. Horsepower at tracks under 1.5 miles and road courses was increased from 670 to 750, a change intended to improve racing action on shorter circuits and road courses. A permanent A-post flap was mandated on all cars to reduce the risk of airborne accidents.
The points system underwent significant restructuring. NASCAR returned to the Chase format used from 2004 to 2013, abandoning the previous elimination-round playoff system. Under the revived Chase format, 16 drivers compete in the postseason without point resets between rounds, rewarding consistent performance across the full playoff stretch. First-place finishes now award 55 points instead of the previous 40, placing greater premium on winning races. The "win-and-you're-in" playoff berth rule was also removed, making the regular-season points battle more consequential throughout the year.
Following the resolution of the 23XI Racing lawsuit, NASCAR updated its charter agreement to offer teams "evergreen" charters that no longer expire at a set date, providing greater long-term stability for team owners.
The 2026 schedule comprises 32 oval races, three road course events, one street track race, and three non-championship oval races. Chicagoland Speedway returned to the schedule, and a new street race at Naval Base Coronado was added. Mexico City was removed from the calendar due to a scheduling conflict with the 2026 FIFA World Cup. The Daytona 500 opened the season on February 15, with Homestead-Miami Speedway hosting the championship finale on November 8.
Connor Zilisch of Trackhouse Racing served as the only full-time rookie, having replaced Daniel Suarez, who moved to Spire Motorsports. Zilisch's arrival was one of the most anticipated debuts in recent seasons given his rapid rise through junior categories.
Tyler Reddick emerged as the dominant force in the opening portion of the season, becoming the first driver in series history to win the first three races and accumulating five victories in the first nine events. Denny Hamlin also achieved notable success with multiple wins during the early calendar. The season's on-track narrative was repeatedly framed against the grief of Busch's death and the question of which competitor would emerge to challenge Reddick's early dominance across the revamped Chase format.