What is Patentable?

An Explanation of Patentable Subject Matter

Businesses and entrepreneurs often face a critical problem: they fail to recognize patentable subject matter in their innovative products or services and inadvertently forfeit valuable patent rights by entering the marketplace without first filing a patent application. Whether developing cutting-edge digital technologies, advanced electronics, chemical innovations, novel consumer products, or new machinery, innovators must understand how to protect their creations from the outset.

You Must Recognize Patentable Innovations Early and Pursue Patent Protection

In the United States, there is a limited grace period (12 months for utility patents and 6 months for design patents) after public disclosure, sale, or offer for sale of an invention during which a patent application can still be filed. If the application filed is not submitted within this grace period, the invention becomes part of the public domain, and the patent applicant permanently forfeits the right to obtain a patent grant for that invention.

First-time patent applicants, tech startups, and other innovators must understand when to initiate the patent process to avoid losing protection. Understanding patentable subject matter and recognizing potentially patentable innovations enables inventors to investigate patent protection and maximize the commercial value of their developments.

This article provides an overview of the types of inventions that may be protected under U.S. patent law pursuant to 35 U.S.C. §101. We also discuss important aspects of design patents, plant patents, and developments under European patent law to give innovators a comprehensive guide to safeguarding their innovations.

Legal Definition of Patentable Subject Matter Under US Patent Law

Under 35 U.S.C. §101, a patentable invention must be a "new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof." This definition encompasses substantially every invention that falls within the "useful arts," but it is not without limits.

Utility Patents: Processes, Machines, Manufactures, and Compositions

The most common type of patent is a utility patent, which protects functional inventions and innovations. Four categories define utility patent eligibility under U.S. patent law, each requiring that the claimed invention be new, useful, and directed to eligible subject matter.

• Process: A new and useful process consists of a series of steps or acts that achieve a specific result. For example, a patented method for purifying contaminated groundwater through a novel filtration sequence would be a patentable process. Another example is a method for encrypting digital data using a new algorithm that reduces computational load.
• Machine: A machine is a concrete apparatus consisting of moving parts or circuitry. An example would be a robotic arm that assembles smartphones with higher precision than existing robots. Another example is a medical imaging device that utilizes a unique sensor arrangement to improve diagnostic accuracy.
• Manufacture: A manufacture refers to an article produced from raw or prepared materials. An example would be a prefabricated modular wall system for quickly constructing residential homes. Another example could be a non-slip flooring tile with a novel surface texture for better traction.
• Composition of Matter: This category covers chemical compositions and new materials. For instance, a synthetic polymer designed for enhanced flexibility and biodegradability would qualify. A new pharmaceutical compound effective against antibiotic-resistant bacteria would also be a patentable composition of matter.
• Improvement Thereof: An improvement thereof refers to any patentable improvement to an existing process, machine, manufacture, or composition. An example would be an improved braking mechanism for electric scooters that provides faster stopping power under wet conditions. Another example could be a new catalyst that accelerates a well-known industrial chemical reaction at lower temperatures.

To be eligible, the invention claimed must meet the utility requirement, meaning it must serve an intended purpose and provide some identifiable benefit. While the threshold for utility is low, courts and the patent office have occasionally rejected inventions for lacking practical utility, such as perpetual motion machines or other devices that violate the laws of physics.

Judicial Exceptions to Patentable Subject Matter

Despite the breadth of §101, courts have carved out certain judicial exceptions to what is considered patentable subject matter. Subject matter that falls into these judicially created categories are non-patentable:

• Abstract Ideas: These are fundamental concepts that are not tied to a particular technological implementation. For example, the concept of hedging risk in financial transactions, as addressed in Bilski v. Kappos, 561 U.S. 593 (2010), is not patentable. Similarly, a method for organizing human activity, such as managing a dinner reservation schedule without a specific technological advancement, would be considered an abstract idea.
• Laws of Nature and Natural Phenomena: These include natural relationships and naturally occurring substances. For instance, Einstein's formula E=mc² is a law of nature and is not patentable. In Association for Molecular Pathology v. Myriad Genetics, 569 U.S. 576 (2013), the Supreme Court held that isolated naturally occurring DNA sequences are natural phenomena and not patentable, although complementary DNA (cDNA) was found to be patentable because it is not naturally occurring.
• Mental Acts: These are purely mental processes that can be performed in the human mind without the aid of any device or machine. For example, a method for diagnosing medical conditions purely by observing symptoms without using any diagnostic tools would be considered a mental act and not patentable. Another example would be solving a complex mathematical equation in one's head without involving a computer or other tangible device.

A claimed invention that falls into one of these judicial exception categories is not patentable unless it includes additional elements that amount to "significantly more" than the judicial exception itself—a standard articulated in landmark cases such as Alice Corp. v. CLS Bank, 573 U.S. 208 (2014) (regarding abstract ideas implemented on a generic computer) and Mayo Collaborative Services v. Prometheus Labs, 566 U.S. 66 (2012) (regarding laws of nature in medical treatment methods). In practice, this means the invention must incorporate an inventive concept sufficient to transform the judicial exception into a patent-eligible application.

The Other Patentability Requirements: Novelty and Non-Obviousness

To be eligible for a patent grant, an invention must satisfy three primary patentability requirements: (1) it must be within the statutory subject matter defined by §101, (2) it must be novel under §102, and (3) it must be non obvious under §103. This article focuses on the first prong—patentable subject matter.

Novelty Requirement

The novelty requirement ensures that a claimed invention is new and has not been disclosed in the prior art before the filing date of the patent application. Under 35 U.S.C. §102, an invention is anticipated, and therefore not novel, if a single prior art reference discloses each and every element of the claimed invention, either expressly or inherently. Anticipation requires that the prior art enable a person of ordinary skill to make and use the invention without undue experimentation. If an invention is anticipated, it cannot receive a patent grant because it does not add anything new to the public domain. Click for a more in-depth explanation of novelty.

Non-Obvious Requirement

The non-obviousness requirement, set forth in 35 U.S.C. §103, mandates that a claimed invention must not be an obvious variation of the prior art to a person having ordinary skill in the relevant field. Even if an invention is novel, it is not patentable if the differences between the invention and prior art would have been obvious at the time the patent application was filed. Courts assess non-obviousness by considering factors such as the scope and content of the prior art, the differences between the prior art and the claimed invention, and the level of skill in the pertinent art. Click for a more in-depth explanation of obviousness.

Patent Search and Prior Art

A critical step in determining whether your invention is patentable is conducting a thorough patent search and prior art search. The United States Patent and Trademark Office (USPTO) evaluates whether the claimed invention is novel and non obvious in view of the prior art, which includes any printed publication, earlier patent applications filed, or known uses. As each patent application must be tailored to the unique attributes of an invention, a thorough prior art search is essential to achieving a patent grant.

Non-Provisional and Provisional Applications

In the U.S., an application filed can take the form of a provisional application or a non provisional application. A provisional application is a placeholder that establishes an early filing date but is not examined. A non provisional application is the full patent application examined by the USPTO.

Design Patents

A design patent protects the ornamental appearance of an article of manufacture, rather than its utilitarian features. Unlike a utility patent, which protects how an invention works, a design patent protects how an article looks. This includes the shape, surface ornamentation, or a combination of both applied to an article of manufacture.

To qualify for design patent protection, the design must meet several specific requirements:

• Novelty: The design must be new and must not have been publicly disclosed in any prior art reference before the filing date of the patent application. For instance, if an identical beverage bottle shape was already sold or described in a printed publication, the later design would not be novel.
• Non-Obviousness: The design must not be an obvious modification of existing designs to a designer of ordinary skill in the art. For example, merely changing the color of an existing smartphone interface would likely be considered obvious, whereas a fundamentally new graphical user interface layout could be non-obvious.
• Non-Functional: The design must be primarily ornamental and not dictated by function. If the shape or configuration of an object is essential to its function—such as the shape of a key designed specifically to interact with a lock—then it would not be eligible for a design patent. For example, the specific curvatures of a beverage bottle that are purely aesthetic and do not enhance grip or strength would be considered ornamental.
• Applied to an Article of Manufacture: The design must be attached to a tangible object. Purely artistic works such as paintings or sculptures not tied to an article of manufacture are protected by copyright, not by a design patent. For example, a unique chair design, a jewelry piece, or a car hood ornament could each be the subject of a design patent.

The scope of protection for a design patent is limited to the visual features shown in the submitted drawings, making the preparation of accurate and comprehensive drawings critical to the patent process. Term protection for U.S. design patents is 15 years from the date of patent grant, with no maintenance fees required during that period. Click for a more in-depth explanation of design patents.

Plant Patents

Under 35 U.S.C. §161, a plant patent may be granted to anyone who invents or discovers and asexually reproduces any distinct and new variety of plant. The plant must be asexually reproduced (not grown from seed), not found in an uncultivated state, and distinct from known varieties. Examples include new rose or apple tree cultivars. Like utility patents, plant patents last for 20 years from the filing date. Click for a more in-depth explanation of plant patents.

European Patent Law and Industrial Applicability

Under European patent law, the criteria are slightly different but similar in concept. The European Patent Convention (EPC) recognizes patentable inventions if they have industrial applicability, are novel, and involve an inventive step. Under EPC Article 56, the "inventive step" requirement is akin to obviousness; what matters is whether the claimed invention would have been obvious to the person skilled in the art, considering the state of the art as a whole.

Software inventions, for example, are treated more restrictively in Europe and must provide a "further technical effect" beyond a basic computer implementation. European practice also places emphasis on technical processes and disallows claims that are purely business, aesthetic, or mental in nature.

Ownership, Enforcement, and Maintenance

A valid patent gives the patent owner the exclusive right to exclude others from making, using, or selling the patented invention for a limited time. For utility patents in the U.S., that term is generally 20 years from the earliest effective filing date, subject to the payment of maintenance fees.

Ownership initially resides with the named inventors unless assigned. Patents can enter the public domain if maintenance fees are not paid, or if the patent expires.

Other Forms of IP Rights - Not Patentable

It is important to distinguish patents from other forms of intellectual property, as different types of legal protection cover different aspects of creative and commercial endeavors.

• Copyrights vs. Patents: Patents protect inventions and discoveries that fall within patentable subject matter, such as processes, machines, manufactures, compositions of matter, and ornamental designs. In contrast, copyright law protects "respective writings," meaning original works of authorship fixed in a tangible medium of expression. This includes literary works, music, paintings, software code, and architectural works. While a patent might protect a novel mechanism for a musical instrument, copyright would protect the sheet music composed for use with that instrument. Additionally, artistic works such as paintings, sculptures, and films are exclusively within the realm of copyright, not patent protection, unless the artistic work is integrated into an article of manufacture in a novel and ornamental way that could qualify for a design patent.
• Trademarks vs. Patents: Trademarks protect brand identifiers, words, phrases, symbols, designs, or a combination thereof, that distinguish goods or services in the marketplace. Trademarks are registered through the trademark office and serve to indicate the source of a product rather than its functional or ornamental aspects. By contrast, patents protect inventions themselves, not their branding or marketing. For instance, the name "iPhone" and the Apple logo are protected by trademark law, while the underlying technological features of the iPhone (such as touch screen innovations) are protected by utility patents, and the distinctive shape and appearance of the device may be protected by design patents. Trademark protection can last indefinitely, provided that the mark continues to be used in commerce and properly maintained, whereas patent protection is limited to a limited time.

Understanding these distinctions is essential for securing comprehensive intellectual property rights. Innovators often seek overlapping protection—for example, by obtaining patent protection for functional features, copyright protection for related written materials or designs, and trademark protection for product names and logos—to create robust legal safeguards for their creations and business assets.

Conclusion

Entrepreneurs that innovate and development novel products and services should understand how to identify patentable innovations. Whether your innovation is a composition of matter, a technical process, a novel design, or a new plant variety, being able to recognize whether it includes patentable subject matter can mean the difference between acquiring intellectual property rights or forfeiting them.

© 2025 Sierra IP Law, PC. The information provided herein does not constitute legal advice, but merely conveys general information that may be beneficial to the public, and should not be viewed as a substitute for legal consultation in a particular case.