Key Takeaways

  • The FDA Orange Book, officially titled Approved Drug Products with Therapeutic Equivalence Evaluations, lists all drug products approved by the U.S. Food and Drug Administration along with relevant patent and exclusivity information.
  • It plays a central role in patent litigation, ANDA (Abbreviated New Drug Application) filings, and market entry for generic drugs.
  • Only drug substance, drug product, and method-of-use patents are eligible for listing—manufacturing process patents are excluded.
  • The Orange Book promotes transparency by helping generic manufacturers assess risks of patent infringement before launching their drugs.
  • Recent FDA updates modernized Orange Book data structures and clarified reissuance and certification procedures, improving the accuracy of patent listings.
  • The Medicare Modernization Act of 2003 and subsequent regulations expanded the Orange Book’s function in 180-day exclusivity determinations and 30-month litigation stays.
  • The Orange Book also supports risk management and compliance frameworks in the pharmaceutical industry by identifying IP boundaries and regulatory status.

Orange Book listed patents are those patents that the U.S. Food and Drug Administration (FDA) has approved and deemed both safe and effective for the general public's use.

Orange Book Listed Patents

The Orange Book provides information on patents for drugs that the FDA has approved for public use, which makes it much easier for generic drug companies to identify whether or not the drug they wish to manufacture is already patented and FDA-approved. However, not all FDA-approved patented drugs are listed in the Orange Book, and that could be for two reasons:

  • The patent is a process patent and not a patent on the actual medication.
  • The patent holder failed to ask the FDA to include it in the Orange Book.

More specifically, pharmaceutical patents are only permitted if they are ‘"composition" or ‘"method of use" patents. This means that the patent must cover the actual drug compound, formulations of the drug, or the method of treating a certain disease by administering the drug. However, process patents, which identify the method for making the drug compound, are not permitted.

History and Purpose of the FDA Orange Book

The FDA Orange Book was first published in 1980 to promote transparency and competition within the pharmaceutical industry. Its primary goal is to inform the public and drug manufacturers about which drug products are approved under the Federal Food, Drug, and Cosmetic Act. The Orange Book’s distinctive color gave rise to its nickname, while its official title—Approved Drug Products with Therapeutic Equivalence Evaluations—reflects its dual role as both a patent registry and a resource for assessing therapeutic equivalence between brand-name and generic drugs.

The publication’s foundation stems from the Drug Price Competition and Patent Term Restoration Act of 1984 (Hatch-Waxman Act), which balanced incentives for innovation with pathways for generic drug entry. The Act required brand-name drug manufacturers to submit patent information to the FDA, which would then publish it in the Orange Book. This listing process ensures that potential generic applicants can identify any active patents before filing an ANDA (Abbreviated New Drug Application).

Submission of Patent Information to the Orange Book

As of November 21, 2017, the Orange Book drug listing and search results will provide patent submission dates when available. This is in compliance with the final FDA rule that was part of the 2003 Medicare Modernization Act.

By knowing the date the patent was submitted, you will have clarification on whether or not the patent will trigger a 30-month patent litigation stay. Previously, if you had wanted to know the date of submission, you would have had to contact the Orange Book staff. This often caused problems for generic companies when they tried to determine if a patent was late-listed, relisted, or properly listed.

It is important to note that the new information only goes back to 2013, when the FDA first began the collecting of patent information. If you do not find a listed patent, you may still need to contact the office to locate older ones.

Patent Types and Listing Criteria

Only certain types of patents may be listed in the FDA Orange Book. The FDA accepts:

  • Drug substance patents, covering the active ingredient itself.
  • Drug product patents, which protect specific formulations or compositions.
  • Method-of-use patents, which claim specific approved uses of the drug.

Patents that describe manufacturing processes, packaging, or intermediates are not eligible for listing. The FDA requires the patent owner or NDA holder to submit Form FDA 3542 within 30 days of patent issuance to ensure timely listing. This information is then made publicly accessible to promote consistency across the industry.

The FDA also allows electronic submissions and maintains an Orange Book Data Files API, enabling companies and researchers to track updates programmatically—a change implemented as part of the agency’s modernization initiative in 2024.

Benefits of the Orange Book

  • The Orange Book makes it easier for drug makers to monitor for new generic drugs that come on the market and infringe on their own patents. Therefore, such businesses holding patents on FDA-approved drugs will very easily know if new generic versions are being manufactured and sold.
  • If a drug maker finds the new generic version in the Orange Book, it can notify the new creator of possible infringement and can subsequently file a patent infringement suit (without having to see the generic drug that was created).
  • Filing a lawsuit will generate an automatic 30-month hold, meaning that the new generic drug maker cannot sell its drug.
  • The Orange Book is available for anyone to view online, for free.
  • Consumers can view the drug's expiration date and any other pertinent details regarding a specific drug.
  • The Orange Book also displays the dates on which drugs were submitted for patent protection and the dates on which patents became effective. Note that this information is only available for those drugs for which patents were obtained on or after 2013. For any drugs patented before 2013, the interested party must reach out to the FDA for exact dates of patent submissions.
  • The patent submission date also helps generic drug makers know whether or not they can, in fact, create and sell their generic version of that drug and whether or not 30 months have passed since the drug patent became effective.

Role in Generic Drug Approvals and Litigation

The FDA Orange Book is crucial to the ANDA process for generic drug approval. When a generic manufacturer files an ANDA, they must include a Paragraph Certification under Section 505(j)(2)(A)(vii):

  • Paragraph I: No patent information has been filed.
  • Paragraph II: The patent has expired.
  • Paragraph III: The generic applicant will wait until the patent expires.
  • Paragraph IV: The patent is invalid, unenforceable, or will not be infringed.

A Paragraph IV Certification often leads to patent litigation. If a lawsuit is filed within 45 days, the FDA imposes a 30-month stay on approval of the generic application while the courts resolve the dispute. The first generic applicant to successfully challenge a listed patent typically earns 180 days of market exclusivity.

This system encourages early patent challenges and creates a predictable pathway for generic entry while maintaining protections for valid patents.

Requirements for Submitting Reissued Patents

When an original patent is relisted, the new drug applicant (i.e., the generic drug maker) must include information on whether or not a patent submitted for relisting is a reissuance of a patent that was previously submitted for listing. The submission would still be subject to the 30-day time period for timely filing of patent information.

The original patent and the reissued patent would then be treated as one for the purpose of certification requirements. Further, the 30-month holding period, as well as the 180-day exclusivity period, would be counted from the latest day of such reissuance.

Certifications to a Reissued Patent

In the case where a 505(b)(2) or ANDA applicant does not provide a patent certification or statement of the original patent due to untimely filing, it could be considered late-listed. If this occurs, the applicant will be required to provide a patent statement or certification for a reissued patent even if it was filed in a timely manner and does not differ from the patent. Instances where this may occur include:

  • If an applicant submits a paragraph IV certification to an original patent and the patent suit came about within about 45 days of the notice of the certification, the 30-month stay would not be affected.
  • If an applicant submits a section viii statement or a paragraph III certification and submitted a paragraph IV certification, a 30-month stay would be allowed.
  • If an applicant submits a paragraph IV certification to an original patent and no patent suit was initiated within the 45 days that the paragraph IV certification was filed, a 30-month stay could occur.

180-Day Exclusivity for Reissued Patents

There are also instances where there may be a 180-day exclusivity period in the case of an amended patent certification to reissuance of an original patent where paragraph IV certification was submitted. Examples include:

  • If there are multiple applicants for eligibility for 180-day exclusivity, the first one who applied will need to submit a paragraph IV certification to the reissued patent within 30 days of its being listed.
  • If no applicant had submitted a paragraph IV certification on the original patent but then filed their paragraph IV certification after the patent was reissued, 180-day exclusivity could result.

When a listed patent is challenged by an applicant in a supplement or amendment to an ANDA or 505(b)(2) application, a paragraph IV certification must be provided regardless of:

  • The applicant already giving notice to another paragraph IV certification
  • A patent infringement case being started in response to a notice

FDA Modernization and Data Transparency Efforts

In recent years, the FDA has launched multiple modernization projects to make Orange Book data more transparent and interoperable. These updates include:

  • API Integration: Developers and companies can now access structured Orange Book data through the FDA’s open-data interface.
  • Patent Submission Tracking: Public visibility into patent listing and delisting actions.
  • Exclusivity Code Updates: Clearer categorization of exclusivity periods for biologics, complex generics, and small molecules.
  • Clarified Patent Delisting Procedures: Ensuring timely removal of expired or withdrawn patents.

These updates were designed to improve the accuracy of patent listings, facilitate compliance monitoring, and support drug competition and patent policy analysis.

Clarification of 20-Day Period

With the proposed FDA rules, there would be clarification for the time frame in which a notice of a paragraph IV certification to a patent can be provided to an NDA holder as well as each patent owner.

  • The new rules clarify the practice that a notice sent before an FDA acknowledgment letter or paragraph IV acknowledgment letter is invalid.
  • According to the rules, when a patent is issued after the NDA approval is received, any notice that has been sent before the first working day after the patent was published in the Orange Book would be invalid.
  • The new rules provide specifics about the calculation of the 20-day period for delivering notices. The first day of the 20-day period will commence the day after the date of the postmark on the paragraph IV acknowledgment letter. All weekdays are to be included except for federal holidays. If the deadline is not met, the FDA will move the date of submission by the number of days past the time frame the applicant took to submit.

Certification for a Patent That Was Reissued to the Original Drug Maker

In this instance, you are a generic drug maker who received a certification or applied for a new drug after you noticed that the original drug maker was in fact listed in the Orange Book. If you were required to obtain a certification or statement to the original patent of the original drug maker, then you will be required to obtain a new certification or statement for any reissued patents for that particular drug. However, if you weren't required to submit such a certification after you initially applied for the new drug, then you won't need to do so for any reissuances.

Risk Management and Compliance Applications

Beyond its legal and regulatory purposes, the FDA Orange Book also serves as a risk management tool. Pharmaceutical companies use the data to assess patent exposure, plan market-entry strategies, and maintain compliance with intellectual property laws. Integrating Orange Book data into enterprise risk management frameworks helps identify potential infringement risks early in product development.

For example, organizations adopting Orange Book Risk Management Principles align their R&D and legal teams by creating centralized tracking systems for patent expirations and exclusivity windows. This approach minimizes litigation risk and supports data-driven decision-making during drug development.

Medicare Modernization Act of 2003

In 2015, the FDA issued regulations that had long been awaited to implement the Medicare Modernization Act of 2003. The proposed rules list multiple provisions for:

  • Submitting patent by NDA holders
  • Patent certifications by ANDA and 505(b)(2) applicants
  • Notices for paragraph IV certifications
  • The particulars of 30-month litigation
  • Other supplements to ANDA and 505(b)(2) applications

Recent and Future Developments

As of 2025, the Orange Book celebrates its 45th anniversary, marking decades of evolution in regulatory science and pharmaceutical innovation. Current discussions within the FDA and policy groups focus on expanding the Orange Book’s scope to include biosimilar products and complex generics that currently fall outside its traditional framework.

The FDA also aims to clarify patent use codes and strengthen collaboration with the U.S. Patent and Trademark Office (USPTO) to improve patent accuracy and prevent overlisting. These ongoing updates reflect the FDA’s commitment to maintaining a transparent and competitive pharmaceutical marketplace while safeguarding public health.

Frequently Asked Questions

1. What is the FDA Orange Book used for? The FDA Orange Book lists approved drug products and their associated patents and exclusivities, helping generic manufacturers assess whether they can legally produce equivalents.

2. Who submits information to the FDA Orange Book? Brand-name drug manufacturers (NDA holders) submit their patent details to the FDA for inclusion, typically within 30 days of patent issuance.

3. Are all patents related to a drug listed in the Orange Book? No. Only drug substance, drug product, and method-of-use patents are eligible for listing. Process and packaging patents are excluded.

4. How does the Orange Book affect generic drug approval? Generic applicants must certify against each listed patent. A Paragraph IV certification can trigger patent litigation and a 30-month approval delay.

5. Is the Orange Book relevant for biologics? Not yet. Biologics are tracked in a separate database—the Purple Book—but future FDA efforts may harmonize data across both systems.

If you need help with reviewing Orange Book listed patents or you are unsure whether or not you can apply for a new generic drug based on what you find in the Orange Book, you can post your legal need on UpCounsel's marketplace. UpCounsel accepts only the top 5 percent of lawyers to its site. Lawyers on UpCounsel come from law schools such as Harvard Law and Yale Law and average 14 years of legal experience, including work with or on behalf of companies like Google, Menlo Ventures, and Airbnb.