What Is a Patent? Types, Costs, and How Long Protection Lasts

What Is a Patent?

A patent is a government-granted property right that gives an inventor exclusive control over an invention for a defined period. In exchange for publicly disclosing the details of the invention — allowing others to learn from and eventually build upon it — the inventor receives a temporary monopoly on making, using, selling, and importing the patented invention. This bargain between inventor and society is the philosophical foundation of patent law.

In the United States, patents are granted by the US Patent and Trademark Office (USPTO). The US follows a first-to-file system since the America Invents Act of 2011: when two inventors independently develop the same invention, the patent generally goes to whoever filed first, not whoever invented first. This makes timely filing strategically important.

The Three Types of US Patents

The USPTO issues three fundamentally different types of patents, each protecting a different category of innovation:

• Utility patents: By far the most common type, covering the functional aspects of inventions — how something works, how it is made, or how it is used. Utility patents protect machines, processes, manufactured articles, and compositions of matter (including chemical compounds and pharmaceuticals). A new drug, software algorithm, manufacturing process, or mechanical device would each be candidates for a utility patent. Utility patents are granted for 20 years from the filing date.
• Design patents: Protect the unique ornamental or aesthetic appearance of a functional article — the way something looks, not the way it works. Apple's design patents on the shape and appearance of the iPhone interface are famous examples. Design patents last 15 years from the grant date (changed from 14 years by a 2023 law change implementing the Hague Agreement).
• Plant patents: Protect asexually reproduced, distinct, and new varieties of plants (other than tuber-propagated plants and plants found in uncultivated nature). These are relatively rare — fewer than 1,500 are granted annually. Plant patents last 20 years from the filing date.

Patent Eligibility: What Can Be Patented?

Not every invention qualifies for patent protection. US patent law requires that an invention be:

• Patent-eligible subject matter: Natural phenomena, abstract ideas, laws of nature, and products of nature are not patentable (these are Mayo/Alice doctrine issues for software and business method patents particularly).
• Novel: The invention must be new — not previously disclosed to the public in any prior art (earlier patents, publications, or public use).
• Non-obvious: The invention must not have been obvious to a person with ordinary skill in the relevant technical field at the time of the invention, given the prior art that existed.
• Useful: The invention must have a specific, substantial, and credible utility (a very low bar for most practical inventions).

The non-obviousness requirement is the most frequently litigated. Courts examine whether the differences between the claimed invention and prior art would have been obvious to a skilled practitioner — a subjective test that produces considerable uncertainty and dispute.

The Patent Application Process

Obtaining a utility patent involves several stages:

1. Provisional application (optional): A lower-cost, simplified filing that establishes a priority date without beginning examination. Valid for 12 months, after which a full non-provisional application must be filed or the priority date is lost. Commonly used to establish rights quickly while the invention is being refined.
2. Non-provisional utility patent application: The formal application includes a specification (description of the invention), drawings where necessary, and claims — the precise legal language defining what the patent protects. Claims are the heart of a patent; skilled drafting of claims is where much of the attorney's value lies.
3. USPTO examination: A patent examiner reviews the application for compliance with patentability requirements. The examiner typically issues at least one office action rejecting some or all claims. The applicant responds, often amending claims or arguing against rejections. This back-and-forth (prosecution) can take 2–3 years on average, longer in crowded technology fields.
4. Allowance and issuance: When the examiner is satisfied, the application is allowed and the patent issues upon payment of an issue fee.

How Much Does a Patent Cost?

Patent costs vary significantly depending on the complexity of the invention and whether you use an attorney:

• USPTO filing fees: Government fees for a non-provisional utility patent application (regular entity) include a basic filing fee (~$320), search fee (~$700), and examination fee (~$800). Maintenance fees are required at 3.5, 7.5, and 11.5 years after grant to keep a utility patent in force — totaling roughly $13,000 for a large entity over the patent's life. Small entities (independent inventors, small businesses under 500 employees) pay 60% of standard fees; micro entities pay 40%.
• Attorney fees: For inventions of moderate complexity, attorney fees for drafting and prosecuting a utility patent through allowance typically range from $10,000 to $30,000. Complex technologies (semiconductors, biotech) can cost $50,000 or more. Design patents are simpler and may run $2,000–$5,000 in attorney fees.
• Total cost: Expect to spend $15,000–$35,000 for a typical utility patent from application through grant, more for complex technologies or contested prosecution. International patent protection (through the PCT system and national phase filings in individual countries) multiplies costs substantially.

When Patent Protection Expires

Patent protection is intentionally temporary. A US utility patent provides 20 years of exclusivity from the filing date — not from the grant date. Because examination typically takes 2–3 years, effective market exclusivity is often closer to 17 years from grant. Maintenance fees must be paid at regular intervals to keep the patent in force throughout its term; failure to pay results in the patent expiring early.

Pharmaceutical patents often appear to last longer because of patent term extension under the Hatch-Waxman Act, which can add up to 5 years to compensate for time lost during FDA regulatory review. Patent term adjustments (PTAs) may also extend a patent if the USPTO caused delays during examination.

After a Patent Expires: The Public Domain

Once a patent expires, the invention enters the public domain and anyone may freely make, use, and sell it without permission or royalty payments. This is by design — the patent system trades a temporary monopoly for permanent public access after expiration. The expiration of drug patents is what allows generic manufacturers to produce affordable copies; the expiration of the original Wright Brothers aircraft patents opened aviation to widespread development. Patent expiration is thus a feature, not a bug, of the intellectual property system.