A patent is a type of intellectual property issued by the U.S. federal government for an invention. A patent owner is granted certain rights for a limited period of time in exchange for public disclosure of the invention. Among other benefits, the patent owner can exclude others from making, using, or selling a patented invention without their permission throughout the United States.

The United States Patent and Trademark Office (USPTO), an agency of the U.S. Department of Commerce, is responsible for examining and issuing patents.

The USPTO issues three types of patents - utility patents, design patents, and plant patents. Utility patents are for useful inventions and protect the way an invention is used and how it works. Design patents are for the visual ornamental characteristics in, or applied to, an article of manufacture and protect the way an article looks. Plant patents are for the invention or discovery and asexual reproduction of a distinct and new variety of plant, other than a tuber propagated plant or a plant found in an uncultivated state and generally protect against the reproduction or making, using, offering to sell, selling, or importing a reproduced plant or any of its parts.

Three types of utility patent applications can be filed in the United States - provisional, nonprovisional, and Patent Cooperation Treaty (PCT) applications.

A provisional patent application is not examined, rather it is a placeholder patent application that does not have to meet the formal requirements of a nonprovisional patent application.  A provisional application can lend its filing date to a nonprovisional application for the same invention so long as the nonprovisional application is filed while the provisional application remains pending.  A provisional application has a pendency that lasts 12 months and this period cannot be extended.  
Provisional applications provide some extra time to pursue the commercial viability of an invention before pursuing a nonprovisional application.  Further, a provisional application does not start the 20-year term, thus, when you file the non-provisional a year later, in some cases you are effectively adding one year to the back end of the patent life.  

A nonprovisional patent application must include a specification, including a description of the invention, at least one claim, and drawings (as necessary).  The inventors must be identified, along with their city of residence and country/countries of citizenship, and must sign an oath or declaration. Any documents known to the inventors or patent professionals who were involved in filing the application must be submitted for consideration during the examination. This includes any documents that an Examiner at the United States Patent and Trademark Office (USPTO) would find relevant to the patentability of any of the claims in the patent application.

Each person who contributed to the conception of the invention set forth in any claim included in the patent application must be listed as an inventor in the patent application. If only one person contributed to the conception of the invention set forth in the claims of the patent application, that person is the sole inventor in the patent application. If multiple persons contributed to the conception of the invention set forth in the claims of the patent application, each of those persons is a joint inventor in the patent application. A person who did not contribute to the conception of the invention set forth in any claim of the patent application should not be listed as an inventor in the patent application.

Under the U.S. Patent Act, ideas that are directed to “any new and useful processes, machine, manufacture, or composition of matter, or any new and useful improvement thereof” are eligible for a patent. A process may be any process, act or method, and primarily includes industrial or technical processes. The term “manufacture” refers to articles that are made and include all manufactured articles. The composition of matter relates to chemical compositions and may include mixtures of ingredients as well as new chemical compounds. These classes of subject matter taken together generally include most things made by man and the processes for making them.

In order for a patent application to become a granted patent, the claims in the patent application must at least be subject matter eligible, useful, novel, non-obvious, definite, enabled, and meet a written description requirement.

An Examiner at the United States Patent and Trademark Office (USPTO) is assigned to each patent application and determines whether to issue a patent for the application based on whether or not it satisfies a set of patentability requirements.

Examiners serve to assess the patentability of invention(s) claimed under conditions set forth in Title 35 of the United States Code (e.g., §§101, 102, 103, and 112).  Examiners comply with the standards and policies set forth in Title 35 of the United States Code, Title 37 of the Code of Federal Regulations (CFR), and the Manual of Patent Examining Procedure (MPEP).  For example, 37 CFR 1.104 requires Examiners to make a thorough study and investigation of the patent application and the prior art related to the subject matter of the claimed invention.

Judicial exceptions to patent-eligible subject matter include natural phenomena or laws of nature, and abstract ideas. 
Examples of natural phenomena or laws of nature may include products of nature, isolated DNA, a cloned farm animal such as a sheep, a correlation between variations in non-coding regions of DNA and allele presence in coding regions of DNA, a correlation that is the consequence of how a certain compound is metabolized by the body, a correlation between the presence of an enzyme in a bodily sample (such as blood or plasma) and cardiovascular disease risk, electromagnetism to transmit signals, qualities of bacteria such as their ability to create a state of inhibition or non-inhibition in other bacteria, single-stranded DNA fragments known as “primers”, the chemical principle underlying the union between fatty elements and water, or the existence of cell-free fetal DNA (cffDNA) in maternal blood.
Abstract ideas not integrated into a practical application may include (a) mathematical concepts, such as mathematical relationships, mathematical formulas or equations, or mathematical calculations; (b) certain methods of organizing human activity, such as fundamental economic principles or practices (including hedging, insurance, and mitigating risk); commercial or legal interactions (including agreements in the form of contracts; legal obligations; advertising, marketing or sales activities or behaviors; and business relations); managing personal behavior or relationships or interactions between people (including social activities, teaching, and following rules or instructions); and (c) mental processes, such as concepts performed in the human mind.

Unless a patent applicant files a non-publication request, U.S. patent applications are automatically published after 18-months from their earliest priority date.     

A provisional patent application is not examined, rather it is a placeholder patent application that does not have to meet the formal requirements of a nonprovisional patent application.  A provisional application can lend its filing date to a nonprovisional application for the same invention so long as the nonprovisional application is filed while the provisional application remains pending.  A provisional application has a pendency that lasts 12 months and this period cannot be extended.  
Provisional applications provide some extra time to pursue the commercial viability of an invention before pursuing a nonprovisional application.  Further, a provisional application does not start the 20-year term, thus, when you file the non-provisional a year later, in some cases you are effectively adding one year to the back end of the patent life.  

An applicant can prevent the USPTO from publishing a patent application before it is issued by filing a non-publication request. In an application in which a non-publication request has been, the invention disclosed in the patent application cannot be the subject of an application filed in another country, or under a multilateral international agreement that requires publication 18 months after filing.

Yes, 35 U.S.C. 122(e) provides a mechanism for third parties to submit patents, published patent applications, or other printed publications of potential relevance to the examination of a patent application with a concise description of the asserted relevance of each document submitted.  Under 35 U.S.C. 122(e), such submissions may be made before (1) the later of (i) 6 months after the date of publication or (ii) the date of a first Office action on the merits rejecting any claims, or (2) before the date of a notice of allowance, if earlier.  This new provision was effective on September 16, 2012, and applies to any patent application.  You can find more details at https://www.uspto.gov/patents/initiatives/third-party-preissuance-submissions.

A patent owner has the right to exclude others from making, using, offering to sell, selling, or importing a patented invention in the United States without their permission. To enforce these rights, the owner can bring a patent infringement lawsuit, or add a patent infringement counterclaim to a lawsuit filed against them. The patent owner can also provide permission to use their patented invention through a contract called a license. In exchange for granting permission to use a patented invention in a license, the patent owner collects payments or other benefits called royalties. A patent owner may also sell their patent and the associated rights to a person or company.

An assignment is a transfer by a party or person of all or part of its right, title, and interest in a patent or patent application. For example, an assignment may transfer all of an inventor’s rights, title, and interest in a patent application to the inventor’s employer. An assignment document may be recorded with the U.S. Patent and Trademark Office in order to provide legal notice to the public of the assignment. 

A declaration is a statement by a person that the person is the original inventor or an original joint inventor of a claimed invention in a patent application, and that the patent application was made or was authorized to be made by the person. A declaration by each inventor in the patent application must be submitted to the U.S. Patent and Trademark Office while the patent application is pending.

Legal representatives of deceased or unavailable inventors may file an application for a patent in the U.S.  If an inventor dies during the time intervening between the filing of the application and the granting of a patent, the patent may be issued to the legal representative.  An assignee or person who shows sufficient proprietary interest in the application may pursue the patent application on behalf of the deceased or unavailable inventor by submitting an executed substitute statement in place of an inventor’s oath or declaration.

Patent applications are published in the U.S., by default, 18 months from their earliest priority date.  In the U.S., applicants have the option, at the time of filing, to request that the patent office not publish a patent application.  In such a case, the application would not be made public by the patent office until the application issues as a patent.  If the application never matures into a patent and non-publication had been requested, the application would not become public.

A restriction requirement is an action issued by an Examiner that asserts a patent application includes two or more independent and distinct inventions.  The restriction requirement requires the applicant to select a single invention for examination.  Claims directed to an unelected invention may be pursued in a divisional application.

Yes.  In the cases in which the Examiner issues a restriction requirement, any non-elected group of claims can be filed in a copy of the original application called a divisional application. Even when a restriction requirement is not made, one or more copies of the original application, called a continuation application, may be filed.  Each of these has its own claims and is eligible to issue its own patent.  Divisional and continuation applications can only be filed during the time the original application (or divisional or continuation application filed directly/indirectly from it) remains pending.

A continuation application is an application that claims the priority date of an earlier-filed co-pending application, and that is directed to an invention included in the earlier-filed application.  The continuation application can not include any subject matter that was not disclosed in the earlier-filed application and must include at least one inventor of the earlier-filed application.  A continuation application is often referred to as a child application, and the earlier-filed application is often referred to as a parent application.

Similar to a continuation application, a divisional application claims the priority date of an earlier-filed co-pending application.  However, in contrast to a continuation application, a divisional application claims an invention that is independent or distinct from the invention claimed in the earlier-filed co-pending application.  A divisional application is often filed as a result of a restriction requirement issued by the United States Patent and Trademark Office (USPTO).

In general, after filing a utility patent application, the average time to grant is about 3 years. However, it is possible to expedite the examination of a patent application by taking advantage of the Track One prioritized examination program. Under the Track One prioritized examination program, the applicant pays an additional fee at the time of filing of the application to have the application prioritized in the Examiner’s docket. Under the Track One program, the application will receive a final disposition within about 12 months.

The expiration date of a patent is 20 years from the filing date of the utility application. In the event that the patent application is filed with the USPTO claiming priority to a PCT application, the patent expiration date is 20 years from the filing of the PCT application. In some instances, the patent term is extended due to delays caused by the USPTO, which is referred to as Patent Term Adjustment (PTA). PTA adds the number of days of delay caused by the USPTO to the end of the patent term. In addition, certain patents that claim products that require regulatory approval by a government agency, in particular the FDA, may qualify for Patent Term Extension.

In order to keep a granted utility patent in force, maintenance fees must be paid at designated times during the term of the patent. A maintenance fee may be paid without a surcharge at 3 to 3.5 years, 7 to 7.5 years, and 11 to 11.5 years after the date of issue. A maintenance fee cannot be paid early. A maintenance fee may also be paid with a surcharge during the "grace periods" at 3.5 to 4 years, 7.5 to 8 years, and 11.5 to 12 years after the date of issue. If the maintenance fees are not timely paid, the patent will expire. In the event that the maintenance fees are not timely paid in error, and the owner of the patent wants to get the patent rights reinstated, a petition to the USPTO is required, along with payment of certain fees. One of the requirements of the petition is a statement that the delay in payment of the maintenance fee was unintentional.

Ownership of a patent gives the patent owner the right to exclude others from making, using, offering for sale, selling, or importing into the United States the invention claimed in the patent.  For applications filed on or after September 16, 2012, the original applicant is presumed to be the owner of the application for an original patent.  For applications filed before September 16, 2012, the ownership of the patent (or the application for the patent) initially vests in the named inventors of the claimed invention in the patent. Ownership of a patent may be transferred from the owner to another party by assignment of the patent via a contractual agreement.  To maintain records of ownership of patent applications and patents, assignments are recorded with the USPTO.  It is important to note that many employers require their employees to assign their rights to an invention, developed while performing duties as an employee, to their employer according to the terms of an agreement, such as an employment contract.  

A patent application or patent may be jointly owned by more than one inventor and/or assignee.  In the absence of an agreement to the contrary, each of the joint owners of a patent may make, use, offer to sell, or sell the patented invention within the United States, or import the patented invention into the United States, without the consent of and without accounting to the other owners.  In addition, joint owners of a patent application or patent must work together in matters before the USPTO, such as the selling of the entire patent, providing an exclusive license, or pursuing infringement claims.  

A third-party competitor can challenge your patent after the grant of the patent.  Inter partes review (IPR) is a trial proceeding conducted at the Patent Trial and Appeal Board to review the patentability of one or more claims in a patent only on a ground that could be raised under §§ 102 or 103, and only on the basis of prior art consisting of patents or printed publications.  For first-inventor-to-file patents, the inter partes review process begins with a third party filing a petition after the later of either: (1) 9 months after the grant of the patent or issuance of a reissue patent; or (2) if a post-grant review is instituted, the termination of the post-grant review. These deadlines do not apply to first-to-invent patents.  The procedure for conducting inter partes review took effect on September 16, 2012, and applies to any patent issued before, on, or after September 16, 2012.  You can find more details at https://www.uspto.gov/patents/ptab/trials/inter-partes-review.