California Labor Code § 2870: Employee Invention Ownership Guide

Key takeaways:

• California Labor Code § 2870 protects an employee’s right to own inventions developed on personal time, with personal resources, and unrelated to the employer’s business.
• An employer’s “all inventions” assignment clause is unenforceable to the extent it reaches inventions protected under § 2870.
• Labor Code § 2872 requires employers to give written notice that the assignment agreement does not apply to § 2870-protected inventions.
• Stanford v. Roche turns on one detail: “I hereby assign” is a present transfer, while “I agree to assign” is only a future promise.
• AB 692 (2025) bans most “stay-or-pay” provisions, further strengthening California’s employee-mobility policy.

In California, an employer’s invention-assignment agreement often looks like it gives the company ownership of every idea an employee touches. For engineers at high-growth technology companies, physicians at academic medical centers, and professors consulting with industry, the stakes are substantial: entire product lines, patent families, and startup equity positions can turn on which inventions the employer actually owns.

California Labor Code § 2870 is the statutory limit on how far those agreements can reach. It reflects a deliberate decision by the California Legislature to protect employee creativity and mobility, even in industries that rely heavily on proprietary innovation. For any California employee-inventor, employer, or startup hiring former employees, understanding § 2870 — together with the companion provisions in §§ 2871 and 2872 — is essential to avoiding costly invention-ownership disputes.

This guide explains the statute, the doctrine that has developed around it, the recent legal developments that shape how California courts apply it today, and the practical steps each side of the employment relationship should take. It builds on our earlier overview of employee-employer intellectual property disputes and recent legal developments, and focuses specifically on the California statute most often at the center of those disputes.

Contents

• What Labor Code § 2870 Says
• Why California Enacted § 2870
• The Three-Part § 2870 Carve-Out
• Labor Code §§ 2871 and 2872 Explained
• Holdover and Trailer Clauses Under California Law
• Stanford v. Roche and Present-Assignment Language
• § 2870 in Specific Contexts
• What AB 692 Changed in 2025
• Practical Guidance for Employees, Employers, and Startups
• When to Seek California IP Counsel
• Frequently Asked Questions About § 2870

What Labor Code § 2870 Says

Labor Code § 2870(a) provides, in relevant part, that any provision in an employment agreement requiring an employee to assign an invention to the employer is not enforceable as to an invention that the employee developed entirely on his or her own time without using the employer’s equipment, supplies, facilities, or trade secret information — except for those inventions that either:

1. Relate, at the time of conception or reduction to practice, to the employer’s business or to the employer’s actual or demonstrably anticipated research or development; or
2. Result from any work performed by the employee for the employer.

Stated in plain terms: California employees own the inventions they make entirely on their own time with their own resources, unless those inventions overlap with the employer’s business or arose out of the employee’s actual work for the employer. The official statutory text is published by the California Legislature at leginfo.legislature.ca.gov.

Why California Enacted § 2870

The purpose of § 2870 is to balance two legitimate interests. Employers have a real stake in inventions arising from their investment in people, facilities, and direction. Employees have an equally real stake in the creative work they do on their own, particularly in a mobile, high-skill workforce in which side projects, open-source contributions, and entrepreneurial experiments are routine.

California’s approach — more employee-protective than most states — is consistent with its broader public policy favoring employee mobility. That policy is reflected in California’s ban on non-compete agreements under Business and Professions Code § 16600, the narrow judicial construction of trade-secret claims brought as de facto non-competes, and, most recently, the 2025 enactment of Assembly Bill 692.

The Three-Part § 2870 Carve-Out

The § 2870 analysis turns on three threshold conditions. All three must be satisfied for the statute to protect the invention from forced assignment to the employer.

What counts as an employee’s “own time”?

“Own time” means time outside the scope of the employment: evenings, weekends, holidays, vacation, and other periods when the employee is not on the clock and not performing work for the employer. Time records, project-management systems, calendar entries, and billing records are routinely used in litigation to establish (or rebut) this element.

Employees who want to preserve § 2870 protection should be disciplined about separating time spent on personal projects from time spent on employer work. Ambiguity here — for example, a commit history that shows after-hours contributions interleaved with work-hours contributions — is often where disputes take root.

What qualifies as employer equipment, supplies, facilities, or trade secrets?

This element is frequently the deciding factor in California invention-ownership disputes. “Equipment” and “facilities” are read broadly: company laptops, VPNs, cloud accounts, office space, internal databases, reserved lab benches, and specialized test equipment can all qualify. So can the employer’s trade secret information, even when accessed from a personal device.

For employees, the practical implication is straightforward but often overlooked. Personal projects should be developed on personal hardware, through personal accounts, using publicly available tools and information. A single reliance on company resources can convert a § 2870-protected invention into one the employer may claim.

The two statutory exceptions that return ownership to the employer

Even when an invention satisfies the two threshold conditions, it still falls outside § 2870’s protection — and can be validly assigned to the employer — if either statutory exception applies.

Exception (1): Relates to the employer’s business or R&D. The invention relates, at the time of conception or reduction to practice, to the employer’s business or to its actual or demonstrably anticipated research or development. “Demonstrably anticipated” is not an invitation for speculation. California courts have required concrete evidence — internal R&D roadmaps, investment decisions, product plans — rather than generalized interest in a field. The line between a mature internal program and a loose idea on a whiteboard is often dispositive.

Exception (2): Results from work performed for the employer. The invention results from any work performed by the employee for the employer. This is the broadest and often the most consequential exception. California courts read “results from” to include inventions that are a natural outgrowth of the employee’s assigned work, not only those directly produced by the assigned tasks.

The Federal Circuit’s decision in Whitewater West Industries, Ltd. v. Alleshouse, 981 F.3d 1045 (Fed. Cir. 2020), applying California law, is a leading example of how broad employment-based assignment language interacts with California’s policy limits. The court declined to enforce a provision that purported to reach inventions conceived after termination, reinforcing that California courts will police overreach even when the contract language is unambiguous.

Labor Code §§ 2871 and 2872 Explained

Section 2870 does not operate in isolation. Two companion provisions govern the mechanics of invention-assignment agreements in California and routinely determine how disputes are resolved.

Section 2871 — no assignment as a condition of employment

Section 2871 prohibits an employer from requiring, as a condition of employment, the assignment of any invention that § 2870 protects. Any provision purporting to do so is unenforceable to that extent.

In practice, this means that a blanket “all inventions” assignment clause cannot be enforced against a § 2870-protected invention, and that an employer cannot discipline, terminate, or refuse to hire an employee for declining to assign such an invention.

Section 2872 — the required written notification

Section 2872 requires that when an employment agreement contains an invention-assignment provision, the employer must provide the employee with written notification that the agreement does not apply to inventions protected under § 2870.

This notification is often missing or buried in boilerplate. Its absence does not automatically void the entire assignment agreement, but it can materially weaken an employer’s position in litigation and is one of the first items experienced counsel examines when evaluating an invention-ownership dispute.

Employers should ensure the § 2872 notice is delivered clearly, in writing, and ideally acknowledged by the employee at the time of hire. For employees, the presence or absence of this notice can be a useful early indicator of how carefully the employer drafted its Proprietary Information and Inventions Agreement (PIIA).

Holdover and Trailer Clauses Under California Law

Some invention-assignment agreements include “holdover” or “trailer” provisions that purport to assign any invention conceived within a specified period after termination — often six or twelve months — if the invention relates to the former employer’s business.

California courts treat these clauses skeptically. The statutory policy embodied in § 2870, the bar on non-compete agreements under Business and Professions Code § 16600, and California’s broader protection of employee mobility together mean that post-termination assignment clauses must be narrowly tailored to legitimate trade-secret protection. Clauses that sweep in inventions conceived on the employee’s own time, without use of trade secrets, and unrelated to actual assigned work are unlikely to survive scrutiny.

Whitewater West is the most recent high-profile application of this principle. More broadly, California courts applying § 2870 and § 16600 have consistently rejected attempts to use post-termination assignment clauses as de facto non-competes.

Stanford v. Roche and Present-Assignment Language

No discussion of employee invention ownership is complete without Board of Trustees of the Leland Stanford Junior University v. Roche Molecular Systems, Inc., 563 U.S. 776 (2011). The decision is not itself a California § 2870 case, but its doctrinal consequences are felt in nearly every California invention-ownership dispute involving academic inventors, consultants, and startup founders.

The core holding: patent rights vest in the inventor at the moment of invention. Those rights transfer to another party only through a valid assignment. The Supreme Court drew a sharp distinction between two common contract phrasings:

• “I agree to assign” — a promise to execute an assignment in the future. Does not itself transfer title.
• “I hereby assign” — a present assignment. Transfers title immediately upon the invention coming into existence.

When an inventor signs one agreement containing “agree to assign” language and a later agreement containing “hereby assign” language, the second agreement can take priority — even when the first was entered earlier and with a party that otherwise would have had the superior claim.

For California employee-inventors, physician-inventors at academic medical centers, and professors consulting with industry, this distinction often determines who owns a patent. Standard university IP policies, hospital consulting agreements, and corporate PIIAs each use different language. Reviewing the operative assignment language — word by word — is a necessary first step in any invention-ownership analysis.

If you are evaluating an invention-assignment agreement in advance of a new role, a startup formation, or a consulting engagement, a confidential California IP strategy consultation is often the most efficient way to identify risk before it matures into a dispute.

§ 2870 in Specific Contexts

Engineers at California technology companies

Software engineers, hardware engineers, and data scientists working at California technology companies are the canonical § 2870 population. Side projects, weekend applications, open-source contributions, and founder-stage prototypes frequently raise § 2870 questions.

Common fact patterns include an engineer who builds a consumer application on personal time and later departs to commercialize it; a founder who begins early-stage development while still employed at a larger company; and a departing engineer whose former employer claims ownership of a pending patent application filed after termination.

§ 2870’s protection is often available in these scenarios — but only where the facts are clean. The most common reasons § 2870 protection fails are (a) use of a company laptop or cloud account for personal work, (b) overlap between the personal project and the employer’s actual or anticipated research and development, and (c) after-hours work that drew on assigned projects at the employer.

Physician-inventors at academic medical centers

Physicians affiliated with academic medical centers, large hospital systems, or integrated health networks typically sign institutional agreements that assign clinical and research inventions to the institution. These agreements often extend beyond federally funded research and can reach into consulting work, device development, and digital health innovations.

§ 2870 still applies — but the analysis is often more complex. Key questions include whether the invention was developed on personal time outside clinical duties, whether hospital resources (EHR access, clinical populations, research infrastructure) were used, and whether institutional IP policy interacts with any separately executed consulting or advisory agreements.

Physician-inventors contemplating a device concept, a clinical algorithm, or a digital health tool should understand the layered ownership analysis before committing significant time or capital.

Academic inventors, professors, and university spinouts

Professors, postdoctoral researchers, and graduate students at California universities sit at the intersection of university IP policy, federal grant requirements (the Bayh-Dole Act), and California state law. Stanford v. Roche is central to this analysis, as is the specific language in each institution’s Patent Policy and sponsored research agreements.

Startup spinouts commonly surface the most difficult issues. A founder-professor may hold a valid § 2870 claim to certain work but not others; inventions tied to federally funded research may trigger university title claims; and consulting agreements with corporate sponsors can introduce a third layer of assignment. Cleanly documenting what was developed where, when, and with whose resources is essential.

Moonlighting and independent side projects

The classic § 2870 scenario: an employee develops a project outside work, using only personal resources, on a topic unrelated to the employer’s business. When the project matures into something commercially valuable, the former employer asserts ownership.

In these cases, § 2870 is typically the central defense. Its effectiveness depends on the quality of the employee’s evidence — time records, commit histories, receipts for personal equipment, location data — and on the scope of the employer’s business at the time the invention was conceived.

What AB 692 Changed in 2025

Assembly Bill 692, enacted in 2025, does not amend § 2870 directly. It does, however, add a significant restriction on “stay-or-pay” provisions — clauses that penalize employees financially for leaving a job before a specified date. With limited exceptions, these provisions are now prohibited under California law.

For invention-ownership disputes, AB 692 matters in two ways. First, it reinforces California’s long-standing policy preference for employee mobility, which courts have historically cited when construing invention-assignment clauses. Second, it narrows the toolkit employers can use to retain critical technical employees, increasing the practical importance of well-drafted and carefully limited invention-assignment provisions.

Read together, § 2870, § 16600, and AB 692 form a consistent regulatory direction: California continues to protect employee mobility and personal creative output, while allowing employers to retain what they have legitimately contributed to. For additional context on the 2025 changes, see our companion analysis: Employee-Employer Intellectual Property Disputes: Understanding Ownership and Recent Legal Developments (2025 Update).

Practical Guidance for Employees, Employers, and Startups

For employees and employee-inventors

Employees who expect to engage in any form of outside inventive activity should take the following steps to preserve § 2870 protection:

• Read every agreement before signing. Assignment language is usually located in a PIIA, an offer letter, or an employee handbook. Pay close attention to the scope of assignment, any holdover clause, and whether the required § 2872 notification is included.
• Separate personal and employer resources rigorously. Personal projects should run on personal hardware, personal accounts, personal cloud storage, and personal tools. Company devices, VPNs, and accounts should not be used for outside work.
• Document the timeline. Keep dated records of invention conception, reduction to practice, and development milestones. Version-controlled repositories with timestamped commits, dated lab notebooks, and photographs with metadata are all valuable.
• Disclose when required. Many PIIAs require disclosure of outside inventive activity. Where required, disclose in writing and retain the acknowledgment.
• Seek counsel before disputes arise. The cost of analyzing an invention-ownership question in advance is a fraction of the cost of litigating ownership after commercial value is on the table.

For California employers

Employers should treat § 2870 compliance as a routine feature of their employment documentation, not an afterthought:

• Include the § 2872 written notification in every PIIA and have it acknowledged at onboarding.
• Tailor assignment clauses to the actual scope of the role and the employer’s actual business. Boilerplate “all inventions” language invites § 2870 challenges and, in some cases, waives arguments the employer might otherwise have had.
• Use present-assignment language (“I hereby assign”) rather than promise-to-assign language (“I agree to assign”) to avoid the Stanford v. Roche trap.
• Keep holdover clauses narrow. Tie any post-termination reach to identified trade secrets rather than broad “related business” categories.
• Maintain invention-disclosure processes. A functioning disclosure program is the most reliable way to separate § 2870-protected inventions from assignable ones at the moment of conception, rather than years later in litigation.

For startups hiring former employees

Startups that hire engineers, scientists, or physicians from larger competitors should conduct a structured diligence review of each new hire’s prior assignment obligations:

• Ask about — and review — every prior PIIA, consulting agreement, and employment agreement.
• Identify any holdover or trailer clauses and analyze whether they survive California scrutiny.
• Where prior-employer IP risk is material, consider clean-room development procedures for the first generation of the startup’s technology.
• Address these risks in the founder and employee agreements themselves, including appropriate representations, warranties, and indemnities.

When to Seek California IP Counsel

Invention-ownership questions are rarely abstract. They typically surface at high-stakes moments — a startup’s formation, a key patent filing, a product launch, a departure from a major employer, or the threat of litigation from a former employer’s counsel. At those moments, the quality of the analysis directly affects commercial outcomes.

A confidential strategy consultation with experienced California IP counsel is often the most efficient way to map the facts onto the statutory framework, evaluate the strength of an ownership claim or defense, and identify the next concrete steps. For employees, founders, physicians, and academics navigating a § 2870 question, Cohen IP Law Group offers a focused advisory session designed to produce an actionable read on the situation.

Request a confidential California IP strategy consultation to discuss your specific invention-ownership question.

Related Reading

• Employee-Employer Intellectual Property Disputes: Understanding Ownership and Recent Legal Developments (2025 Update) — overview of the full IP ownership landscape, including patents, trade secrets, trademarks, and the 2025 Federal Circuit decisions on assignment language.
• Employee/Employer Intellectual Property Disputes — foundational explanation of assignment of invention agreements, work-for-hire, and PIIA/CIIA/EIAC structures under California law.
• Patent Litigation — our approach to invention-ownership and patent-enforcement disputes in California.
• Trade Secret Litigation — representation in departing-employee and misappropriation disputes that often accompany § 2870 issues.

Frequently Asked Questions About § 2870