Instead of competing with rivals by offering more affordable services, federal and state enforcers claim Apple imposed “a series of shapeshifting rules and restrictions” to “extract higher fees, thwart innovation, offer a less secure or degraded user experience, and throttle competitive alternatives.”

Through that conduct, the Justice Department and states allege in the complaint, Apple “built and reinforced the moat around its smartphone monopoly.”

“If left unchallenged, Apple will only continue to strengthen its smartphone monopoly,” U.S. Attorney General Merrick Garland said in a statement.

Apple spokesman Fred Sainz said in a statement that the lawsuit is “wrong on the facts and the law” and that the company “will vigorously defend against it.”

“This lawsuit threatens who we are and the principles that set Apple products apart in fiercely competitive markets,” Sainz said. “If successful, it would hinder our ability to create the kind of technology people expect from Apple—where hardware, software, and services intersect.”

Apple is facing mounting legal and regulatory scrutiny on several fronts, including for purportedly exploiting its grip over competitors and consumers by imposing restrictions and steep fees in its popular App Store.

Critics have long accused the tech giant of undermining smaller companies by barring app makers from using outside payment systems and charging hefty fees on transactions. The company has begun to open up its walled gardens, but competitors have continued to hammer the changes as insufficient.

European regulators fined Apple nearly $2 billion this month, accusing it of “abusing” its influence over music streaming platforms and preventing developers from informing users about “alternative and cheaper” services, the culmination of a years-long investigation. Apple said it plans to appeal the fine, which it said “ignores the realities” of the music streaming industry.

Apple is one of six tech giants subject to more stringent competition restrictions under Europe’s sweeping new rule book, known as the Digital Markets Act, which could force the company to open its products to outside services.

Last year, Apple largely prevailed in an antitrust lawsuit filed by rival Epic Games, maker of the popular Fortnite video game series. A federal appeals court ruled that Epic failed to make its case that Apple controls an app store monopoly under federal law, but that the giant did violate competition laws in California by forcing developers to use its payment services without informing consumers about alternatives.

Major tech companies including Facebook parent Meta and Microsoft have since argued that Apple’s plan to comply with the decision is deeply flawed.

The latest lawsuit alleges that Apple has maintained its iPhone monopoly by disrupting apps that could make it easier for consumers to switch smartphones, blocking mobile cloud streaming services that allow them to enjoy products outside the company’s ecosystem and degrading the quality of alternative messaging apps. Fifteen states including California, New York and Tennessee joined the District of Columbia and the DOJ in filing the lawsuit.

The DOJ lawsuit is the Biden administration’s latest major salvo against Silicon Valley giants over claims they are stifling competition through monopolistic and anti-competitive practices.

The DOJ sued to break up Google’s digital advertising business last year and is fighting the company in court in a separate lawsuit targeting its dominance over search that was launched under the Trump administration.

The Federal Trade Commission, meanwhile, is leading an antitrust lawsuit against Amazon, alleging the e-commerce giant abused its power to stifle competitors, and it previously sued Meta over its dominance in social media.

The Biden administration has pledged to fight corporate consolidation more aggressively than previous administrations.

Under Garland, the department has brought on big-named anti-trust lawyers to lead the section and has notched victories in fighting mergers in the healthcare and and publishing industries.

In January 2023, the law enforcement agency filed a high-stakes lawsuit challenging Google’s dominance in the online ad industry. And in March, JetBlue and Spirit Airlines announced they would drop their merger plans after the Justice Department successfully brought a suit against them.

The Justice Department has requested to significantly increase their antitrust budget in fiscal year 2025 to grow their enforcement capacity.

The Justice Department launched a broad review in 2019 of potential antitrust violations in the tech sector, which morphed into major investigations of several of Silicon Valley’s most powerful players, including Apple and Google.