As of December 2023,[update] it had over 1.5 million members,[6] making it the largest trade association in the United States[7] including NAR's institutes, societies, and councils, involved in all aspects of the residential and commercial real estate industries.

[11] The NAR governs the hundreds of local Multiple Listing Services (MLSs) which are the information exchanges used across the nation by real estate brokers.

[27] RPAC now claims to be the largest trade association PAC in the country and gives around $4 million per year to candidates who support real estate interests.

[33][34] Realtors were prohibited from helping Black homebuyers move into white neighborhoods and faced career-ending penalties for not complying.

[37][38] The National Association of Realtors opposed the Fair Housing Act in 1968, which outlawed racial discrimination in home sales.

Many victims are encouraging the Securities and Exchange Commission to begin aggressively regulating[41] agents and refunding overpayments to homebuyers.

In 2005, the United States Department of Justice filed a formal complaint against the National Association of Realtors for violating Section 4 of the Sherman Antitrust Act.

[42][43] The complaint sought to enjoin the National Association of Realtors "from maintaining or enforcing a policy that restrains competition from brokers who use the Internet to more efficiently and cost effectively serve home sellers and buyers, and from adopting other related anticompetitive rules.

[42][18][44] In 2012, American Home Realty Network, Inc., the operator of NeighborCity, filed antitrust counterclaims in response to a pair of copyright lawsuits, alleging that the "copyright lawsuits filed against it by two multiple listing services with financial backing from the National Association of Realtors are part of a concerted effort by NAR to drive the company out of business and eliminate it as a provider of services to real estate brokers.

[47] Edina Realty is a subsidiary of HomeServices of America, Inc., a Berkshire Hathaway company, which owns real estate brokerage firms in states across the country, including Minnesota, Maryland, North Carolina, Georgia, Washington, Oregon, Arizona, Rhode Island, Connecticut, Iowa, Nebraska, Ohio, Illinois, Kansas, South Carolina, Missouri, Pennsylvania, Indiana, Kentucky, Alabama, and California.

[54][55] The lawsuit, Burnett et al v. National Association of Realtors et al, was heard in the U.S. District Court for the Western District of Missouri in Kansas City, and involved allegations of violations of federal and state antitrust laws by the NAR, HomeServices of America, Keller Williams Realty, Anywhere Real Estate (parent of Coldwell Banker, Century 21 Real Estate, and Sotheby's International Realty) and Re/Max.

[54][55][56] Anywhere and Re/Max had previously settled their liability and agreed to pay lesser damages, leaving NAR, HomeServices and Keller Williams to defend the suit at trial.

[54][55] Upon announcement of the verdict and before final judgment was entered, NAR and HomeServices stated their intention to appeal, and Keller Williams was considering doing so.

[54][55][57] In March 2024, NAR agreed to settle for a reduction of damages to US$418 million, eliminating its rules on commissions, and waiving its right to appeal.

[59] The Wall Street Journal reported the settlement is expected to reduce real estate commissions, force some agents out of the industry, and lead to a decline in NAR’s membership.