What Do You Still Own After Signing an Invention Assignment?

What an Invention Assignment Actually Transfers

Patent rights start with the person who invents. The U.S. Supreme Court opened its decision in Board of Trustees of the Leland Stanford Junior University v. Roche Molecular Systems, Inc., 563 U.S. 776 (2011) with that rule: “Since 1790, the patent law has operated on the premise that rights in an invention belong to the inventor.” The Court added that “an employer does not have rights in an invention ‘which is the original conception of the employee alone’” unless there is an agreement to the contrary, and that “mere employment is sufficient to vest title” was an idea it had rejected.

That is why your employer asked you to sign. The invention assignment is the agreement that moves your rights to the company. Under 35 U.S.C. § 261, patent applications and patents “shall be assignable in law by an instrument in writing.”

Present Assignment Versus a Promise to Assign

The wording matters. Some agreements say you “hereby assign” future inventions; others say you “agree to assign” them. In the litigation behind Stanford v. Roche, the Federal Circuit treated a researcher’s “agree to assign” as, in the Supreme Court’s description, “a mere promise to assign rights in the future,” while a later agreement that said “do hereby assign” “itself assigned” his rights. The company holding the second document came out ahead. If your agreement uses present-tense language, assume ownership of covered inventions passed to the company the moment they came into existence.

The Shop Right When There Is No Assignment

Without an assignment, an employer may still hold a limited right. In United States v. Dubilier Condenser Corp., 289 U.S. 178 (1933), the Supreme Court described the “shop-right”: when an employee, “during his hours of employment, working with his master’s materials and appliances, conceives and perfects an invention for which he obtains a patent, he must accord his master a non-exclusive right to practice the invention.” The employee keeps ownership; the employer keeps the right to use the invention.

Minnesota’s Limit: Minn. Stat. § 181.78

Minnesota caps how far an assignment clause in an employment agreement can reach. Minn. Stat. § 181.78, subd. 1 provides that an assignment provision “shall not apply to an invention for which no equipment, supplies, facility or trade secret information of the employer was used and which was developed entirely on the employee’s own time, and (1) which does not relate (a) directly to the business of the employer or (b) to the employer’s actual or demonstrably anticipated research or development, or (2) which does not result from any work performed by the employee for the employer.” A provision that tries to reach such an invention is “to that extent void and unenforceable.”

In plain English, an invention you made is outside the clause when you can answer yes to every question in the left column and yes to at least one in the right:

Both must be true	And at least one must be true
You used none of the employer’s equipment, supplies, facilities, or trade secret information	The invention does not relate directly to the employer’s business or to its actual or demonstrably anticipated research or development
You developed it entirely on your own time	The invention does not result from any work you performed for the employer

Expect an employer to read these conditions narrowly. Your strongest position is an invention that meets all of them at once: built on your own time and equipment, outside the company’s line of business, and unconnected to your job. One use of a company laptop or one test run in the company lab can put an otherwise personal invention in dispute.

The statute adds two protections. Under subdivision 2, “No employer shall require a provision made void and unenforceable by subdivision 1 as a condition of employment or continuing employment.” Under subdivision 3, an employer whose agreement (entered into after August 1, 1977) requires you to assign inventions “must also, at the time the agreement is made, provide a written notification” to you describing the same exclusion. Look for that notice in your onboarding papers; it is often an exhibit to the agreement. Section 181.78 itself does not state a consequence for an employer that skipped the notice, so a missing notice is a fact to raise with an attorney, not an automatic release. The employer-side view of the same statute is in IP ownership for Minnesota employers.

What You Still Own

After signing a typical invention assignment, you generally still own:

• Inventions outside the clause’s own definition. Many clauses cover only inventions made during employment that relate to the business. Read the definition before assuming the worst.
• Inventions protected by section 181.78. Any part of the clause that reaches them is void.
• Inventions you listed as prior inventions. Most agreements include a schedule for inventions you brought with you.
• Your general skill and know-how. An invention assignment transfers inventions, not your experience. Confidentiality obligations still restrict what company information you may use.

Starting a Business or Joining a Competitor

Leaving does not undo what the agreement already assigned. Before you build a product or accept an offer, take these steps:

1. Find every agreement you signed. The offer letter, the invention assignment, any confidentiality agreement, and any equity or bonus plan documents can each carry IP terms.
2. Read the definition of covered inventions and the time window. Some agreements reach inventions conceived during employment even if you finish them later, and some include a clause reaching inventions made for a period after you leave. Whether such a clause is enforceable is its own question; see post-employment IP assignment clauses and enforceability of assignment of invention clauses.
3. Check what you disclosed. Many agreements require you to report inventions while employed. See invention disclosure requirements.
4. Separate the new work cleanly. Use your own equipment and your own accounts, work on your own time, and keep dated records of when and how you developed the new idea. That record is what proves the section 181.78 conditions if a dispute arises.
5. Leave the employer’s materials behind. Taking files, code, or customer data invites claims against you; see litigation risk from former employer IP.

A noncompete is a separate question. Under Minn. Stat. § 181.988, subd. 2, “Any covenant not to compete contained in a contract or agreement is void and unenforceable,” and the enacting session law makes that section apply to agreements entered into on or after July 1, 2023. The same section excludes nondisclosure agreements and agreements “designed to protect trade secrets or confidential information” from its definition of a covenant not to compete, so your confidentiality obligations survive even where a noncompete does not. More on that in the Minnesota noncompete FAQ.

You Stay the Inventor Even After Assigning Ownership

Inventorship and ownership answer different questions. Ownership says who holds the rights; inventorship says who conceived the invention. Under 35 U.S.C. § 115(a), a patent application “shall include, or be amended to include, the name of the inventor for any invention claimed in the application.” An assignment to your employer does not change that requirement, so your name belongs on the application if you invented what it claims.

You do not need to have contributed to every claim. Under 35 U.S.C. § 116(a), joint inventors may apply together even though “each did not make a contribution to the subject matter of every claim of the patent.” The USPTO’s rule, 37 C.F.R. § 1.45(c), requires each named inventor in a nonprovisional application to have “made a contribution, individually or jointly, to the subject matter of at least one claim.”

If the company leaves you off, or names you on claims you did not invent, the error can be fixed. 35 U.S.C. § 116(c) lets the USPTO amend an application when “through error an inventor is not named,” and 35 U.S.C. § 256 provides the same correction for an issued patent, including by court order. Inventor status is part of your professional record, and it matters if your agreement pays a bonus for patents or if you later need to show what you invented and when.

What the Company Can Ask You to Sign

When an employer or former employer files a patent application on an invention you worked on, it will usually ask for two documents.

Document	What it says	Governing law
Inventor declaration	That the application was made or authorized by you, and that you believe you are an original inventor or joint inventor of a claimed invention	35 U.S.C. § 115(b); 37 C.F.R. § 1.63
Assignment	That you transfer your rights in the invention and the application to the company	35 U.S.C. § 261; your invention agreement

Read the declaration as a statement made under penalty. Under 37 C.F.R. § 1.63(c), a person may not execute it “unless that person has reviewed and understands the contents of the application, including the claims.” Under 35 U.S.C. § 115(i), the declaration must acknowledge “that any willful false statement made in such declaration or statement is punishable under section 1001 of title 18 by fine or imprisonment of not more than 5 years, or both.” Because the rule requires that review, ask for the application and its claims if they were not sent with the documents.

The company can combine the two documents. 35 U.S.C. § 115(e) lets an inventor “under an obligation of assignment” include the declaration statements in the assignment itself. The company can also file the application as the applicant: under 37 C.F.R. § 1.46(a), “A person to whom the inventor has assigned or is under an obligation to assign the invention may make an application for patent,” and the rule names an “employment agreement” as evidence of that obligation.

Before signing either document, check four things:

1. Which application it covers. The assignment should identify the specific application, not every invention you ever made.
2. Whether you invented what the claims describe. If you did not, the declaration is not yours to sign.
3. Whether the invention falls within your agreement. If you believe it falls outside the agreement or within section 181.78, signing an assignment gives that position away.
4. Whether the recitals are accurate. An assignment often recites why the company owns the invention. You can ask the company to correct a recital you believe is wrong before you sign.

What Happens If You Decline

Declining to sign the declaration does not stop the application. Under 35 U.S.C. § 115(d)(2)(B), the applicant may file a substitute statement in place of your declaration for an individual who “is under an obligation to assign the invention but has refused to make the oath or declaration.” The USPTO’s rule, 37 C.F.R. § 1.64(a), allows a substitute statement when the inventor “has refused to execute the oath or declaration.” Under 35 U.S.C. § 118, a patent granted on such an application “shall be granted to the real party in interest.” You remain the named inventor either way.

Declining the assignment is a different matter, and the outcome depends on your agreement:

• If the agreement already says “hereby assign,” ownership of a covered invention may already sit with the company, and your signature on a separate assignment mainly confirms it for the record.
• If the agreement says “agree to assign,” the company can sue to compel the transfer. In Dubilier, the Supreme Court stated that an agreement to assign a patent not yet issued, “if valid as a contract, will be specifically enforced.”
• If the agreement has a cooperation or further-assurances clause, a refusal can itself be a breach, separate from who owns the invention.

Declining makes sense when the invention is genuinely outside the agreement or protected by section 181.78, when you are not an inventor of what the claims describe, or when the document asks you to state something you believe is untrue. In those cases, put your position in writing and keep a copy. Refusing simply because the request is inconvenient, when the invention plainly falls within a valid assignment, usually creates a contract dispute you would lose. An attorney can help with this decision, because the right answer turns on the agreement’s words and the facts of when and how the invention was made.

If You Were a Contractor, Not an Employee

Section 181.78 addresses a provision “in an employment agreement.” If you signed a consulting or independent contractor agreement, expect that agreement’s own wording to control which inventions it reaches, and read its IP section closely. The patent filing mechanics above apply the same way: you are still the inventor, the company may still ask for a declaration and an assignment, and a refusal still allows a substitute statement if you are obligated to assign. For how ownership defaults differ between employees and contractors, see patents for Minnesota employers and the employment law practice area.

Steps Before You Sign Anything

When you receive a patent declaration or assignment, or before you launch a business near your former employer’s field, Aaron Hall recommends this sequence:

1. Gather every agreement you signed with the company, including any section 181.78 notice.
2. Ask for a copy of the patent application and its claims.
3. Compare the claims to what you actually contributed and when you contributed it.
4. Compare the invention to the agreement’s definition and to the section 181.78 conditions.
5. Decide whether to sign as written, sign with corrected recitals, or decline in writing with your reasons.