Over the 1951-1952 winter, Tony Hulman and IMS president Wilbur Shaw put together the IMS Radio Network to broadcast the Indianapolis 500. This was not a new idea but rather it was born of necessity.

The first coverage of the Indianapolis 500 was in 1922 when two small Indianapolis radio stations began broadcasting snippets of the race to the local market. Within three years, WFBM in Indianapolis and WGN in Chicago took over with periodic updates throughout the race. In 1928, NBC covered the final hour of the race live while CBS covered the race in the late 1930s.

Nationwide coverage began in 1939, when the Mutual Broadcasting System broadcast the race. The format was live segments for 15 minutes at the start and the finish with five-minute hourly updates throughout the race. The anchor, Bill Slater, announcing career started after one of the students at the Blake School for Boys in Minneapolis, whose father was a radio executive, suggested that not only did he have the voice for radio but also the sports knowledge.  Among Slater's early radio announcing gigs was the 1933 Army Navy football game on CBS. He was the primary voice of the Paramount News reels beginning in 1936. He covered the 1936 summer Olympics for NBC and announced the New York Yankees and New York Giants baseball games, various college football games, and tennis matches including Wimbledon.

The Mutual Broadcast System began as a cooperative in September 1934 with WOR (Newark), WGN (Chicago), WXYZ (Detroit), and WLW (Cincinnati) as members. It covered the race from 1939 to 1950. Prior to WW II, the Mutual Broadcast System used the production services of WLW. After WW II, Indianapolis station WIBC provided the production services for the race.

In 1950, Slater was expected to miss the Indianapolis 500 because of illness. He was replaced as the anchor by Sid Collins who had previously reported from one of the south turns. When Slater arrived for the broadcast duties, he shared them with Collins. In 1951, Mutual substantially raised its advertising rates for the race, and its sponsor, Perfect Circle Piston Rings, pulled it financial support. Without a primary sponsor, the broadcast of the race was in limbo. At the last minute, Shaw convinced WIBC to cover the race using the same format as Mutual’s. WIBC shared its coverage with twenty-five other Mutual affiliates. The broadcast began about 15 minutes before the start of the race. After the 1951 race, the other four Indianapolis radio stations complained of WIBC providing the coverage.

Shaw and Hulman launched the Indianapolis Motor Speedway Radio Network in-house using the on-air talent and production services from WIBC. For 1952, not only were all five Indianapolis radio stations represented by on-air announcers led by Sid Collins of WIBC, Collins led an effort to announce the race in its entirety and all five Indianapolis radio stations broadcast the race. The affiliates to the IMS Radio Network expanded to 130 stations nationwide. Expansion of the network grew rapidly and in 1955, coverage was provided to all 48 states. When Hawaii and Alaska were added to the United States, the coverage grew. Worldwide shortwave transmission through the Armed Forces Radio Network was added. By 1976, there were 1200 stations and over 100 million listeners to the race.

Sid Collins died unexpectedly in early May 1977 after being diagnosed with Lou Gehrig’s Disease. He was replaced by Paul Page, whom Collins had mentored, from 1977 to 1987. A variety of other people have served as the chief announcer with Mike King serving for fifteen years from 1999 until 2013. At that point, Paul Page returned to the chief announcer role.

When television coverage of the Indianapolis 500 began in 1986, stations in the IMS Radio Network steadily declined. It remains a crucial part of reaching out to fans, particularly in the Indianapolis area as television coverage is blacked out if the race is not sold out. With the beginning of the IndyCar league, the IMS Radio Network provided coverage of races beside the Indianapolis 500. Today, it is known as the IndyCar Radio Network and is available on Sirius, on line streaming platforms, and shortwave radio.

In 1994 when NASCAR started the Brickyard 400 at the Speedway, the IMS Radio Network provided coverage of that race. It was the only NASCAR race not covered by either the Performance Racing Network (PRN) or the Motor Racing Network (MRN). In 2004, PRN began jointly producing the Brickyard 400 races and the broadcast streaming rights became a part of PRN.