The Inevitable Disclosure Doctrine in 2026: Why Trade Secret Lawsuits against Former Employees Are Harder in California

About the author: Scott Lesowitz is a 2007 Harvard Law School graduate and former Assistant United States Attorney whose civil litigation practice is based in Southern California. Scott is a founding partner of Lesowitz Gebelin LLP. Scott lives in San Diego with his wife, three children, and bernedoodle. Scott represents clients throughout California, including San Diego, Los Angeles, and Orange Counties.

An issue that arises frequently in trade secret litigation is that an employer is concerned about trade secret misappropriation when an employee leaves to work for a competitor or to start a competing business. The now former employer will often believe it is inevitable that the former employee will use or otherwise misappropriate the trade secret in the new employment or in the new business.

However, there may be no tangible evidence of trade secret misappropriation (a term that encompasses theft, use, or disclosure of trade secrets) other than the similarity between the employee’s new job duties and the employee’s old job duties.

Can the employer file a lawsuit and obtain a temporary restraining order or injunction against the former employee? If so, what would be the permissible scope of the injunction?

I am an experienced trade secret litigator based in San Diego, and as I will explain, due to California rejecting the inevitable disclosure doctrine and having a strong policy against non-competition agreements and restraints on trade, the situation is more difficult–but not hopeless–for former employers in California.

The Inevitable Disclosure Doctrine in Trade Secret Misappropriation Cases

In most states, even when there is no tangible evidence of trade secret misappropriation, the employer might be able to obtain an injunction barring the former employee from working for the competitor or running the new competing business because of a high likelihood that trade secrets will be used or disclosed. This is the inevitable disclosure doctrine.

While the nuances may be different in a given state, in general, under the inevitable disclosure doctrine, “a plaintiff may prove a claim of trade-secret misappropriation by demonstrating that a defendant’s new employment will inevitably lead him to rely on the plaintiff’s trade secrets.” Nonmacher v. Tri-State Iron & Metal Co., 2025 Ark. App. 356, 32 (2025).

As one court explained, under the inevitable disclosure doctrine, when “an employee with detailed and comprehensive knowledge of an employer’s trade secrets and confidential information has begun employment with a competitor of the former employer in a position that is substantially similar to the position held during the former employment,” the court may enjoin (bar) the employee from engaging in the new employment or position. McGowan & Co., Inc. v. Bogan, 93 F.Supp.3d 624, 645 (S.D. Tex. 2015).

Thus, the inevitable disclosure doctrine is a powerful tool when the former employer wants a temporary restraining order, preliminary injunction, or permanent injunction against a former employee, but lacks solid evidence of actual trade secret misappropriation.

California Rejects the Inevitable Disclosure Doctrine

California rejects the inevitable disclosure doctrine. Hooked Media Group, Inc. v. Apple Inc., 55 Cal.App.5th 323 (2020); Whyte v. Schlage Lock Co., 101 Cal.App.4th 1443 (2002).

This poses a problem for the former employer. If the former employer must wait to file suit until a trade secret has been used or disclosed, irreparable damage may have already occurred by the time the former employer files the lawsuit.

However, while California rejects the inevitable disclosure doctrine, courts in California may issue an injunction in a case of “threatened misappropriation.” Applied Medical Distribution Corp. v. Jarrells, 100 Cal.App.5th 556 (2024); Central Valley General Hospital v. Smith, 162 Cal.App.4th 501 (2008). That begs the question, what is threatened misappropriation?

Threatened misappropriation may be proved in a number of ways, such as by providing evidence that the former employee intends to use the trade secret or evidence that the former employee wrongfully rejected a demand to return the trade secret. However, mere possession of a trade secret originally acquired by proper means is insufficient to establish threatened misappropriation. Cypress Semiconductor Corp. v. Maxim Integrated Products, Inc., 236 Cal.App.4th 243, 265 (2015); Central Valley General Hospital.

California Law Greatly Restricts Non-Competition Agreements and Restraints on Trade

Except in narrow circumstances, in California, non-competition agreements are unenforceable. Unlike most other states, this is true even if the agreement is limited in time and geographic scope. California Business and Professions Code § 16600.

This is not a new innovation of California law. California law has voided noncompetition agreements except in narrow circumstances since 1872.

California courts are reluctant to allow trade secret law to be a way of limiting Section 16600 and the prohibition of non-competition agreements. Therefore, in California, courts are limited in their ability to simply bar employment or the engaging in a business altogether, even in the face of threatened misappropriation. The Retirement Group v. Galante, 176 Cal.App.4th 1226 (2009).

While courts will almost certainly not enter a blanket prohibition against employment or the engaging in a business altogether based on threatened misappropriation, courts can prohibit the former employee and his or her new employer or new business from using or otherwise misappropriating trade secrets. Additionally, courts can take measures to undo any advantage from prior acts of misappropriation. While not as far-reaching as the relief that may well be available in other states, this still may accomplish the goals of the employer.

For example, if a former employee has a customer list that constitutes a trade secret, a court might be able to order the employee not to solicit customers on the customer list. Perry v. Stuart, 111 Cal.App.5th 472 (2025); Morlife, Inc. v. Perry, 56 Cal.App.4th 1514 (1997). It should be noted that not all customer lists are trade secrets. Customer lists must be sufficiently secret, difficult to reconstruct, and valuable to constitute trade secrets.

Additionally, an injunction may prohibit the former employee from using or disclosing trade secrets and also order the return of documents and media containing the trade secrets. Central Valley General Hospital v. Smith, 162 Cal.App.4th 501 (2008).

So, in summation, in California, it is more difficult for businesses to obtain injunctions against former employees. However, businesses still have a likelihood of obtaining effective relief. Furthermore, the business may be able to obtain injunctive relief against both the former employee and the new employer or business.

Businesses should be cognizant that in trade secret cases, whether or not a preliminary injunction is granted barring acts of trade secret misappropriation pending trial (which may not occur for two or three years), may be the most important part of the litigation. Therefore, for all parties involved, it is important to have an experienced attorney as soon as practicable.

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