Patent Term Extension

Examination delay

USPTO failed to: mail first OA within 14 months of filing, respond to applicant submission within 4 months, act within 4 months after an appeal board decision, or issue patent within 4 months of payment of issue fee.

Extended prosecution

Application pending for more than 3 years (36 months from filing date to issuance), excluding: RCE pendency, appeal pendency, secrecy order period, interference/derivation periods.

Appellate proceedings

Delays due to interference/derivation proceedings, secrecy orders, and successful appellate review (the portion exceeding what would be expected in normal examination).

Applicant delay

Days deducted for applicant actions that extended prosecution: failure to respond within 3 months, filing RCEs, requesting continued prosecution, appealing an allowable rejection.

Eligible products

• Human drugs (new chemical entities, biologics)
• Medical devices (Class III PMA)
• Animal drugs
• Food additives
• Color additives

Eligible patents

• Patent claiming the approved product
• Patent claiming a method of using the product
• Patent claiming a method of manufacturing the product
• Only one patent per product can receive PTE

Calculation

• ½ of clinical testing period (Phase I–III)
• + Full regulatory review period (IND to NDA/BLA submission)
• + Full FDA review period (submission to approval)
• = Total regulatory review period → halved for PTE

Caps and limits

• Maximum PTE: 5 years
• Remaining term after PTE: cannot exceed 14 years from FDA approval date
• PTE covers only the approved product (and equivalent products) — not other uses
• One PTE per product, regardless of how many patents cover it

What is Patent Term Adjustment (PTA) and how is it calculated?

Patent Term Adjustment (PTA) under 35 U.S.C. § 154(b) compensates patent owners for days lost to USPTO delays during prosecution. The USPTO calculates PTA automatically and prints it on the patent face. PTA accumulates from three types of delay: (A) delays from USPTO failure to meet statutory prosecution timelines (e.g., failure to mail first office action within 14 months of filing, or failure to respond to applicant submissions within 4 months); (B) delays when the application is pending for more than 3 years (excluding time applicant RCEs, appeals, or secrecy orders are pending); and (C) delays from appellate or interference proceedings beyond what is expected. These delays are added together, then reduced by any 'applicant delay' — time the applicant failed to respond within 3 months. PTA can add months or years to a patent term. For example, a patent prosecuted for 5 years might receive 1–2 years of PTA, extending the effective expiry from filing+20 to filing+21 or +22.

What is the difference between PTA and PTE?

PTA (Patent Term Adjustment, § 154(b)) compensates for USPTO prosecution delays and applies to every utility patent automatically — you do not need to apply for it. PTE (Patent Term Extension, § 156) applies exclusively to patents claiming a product that required FDA regulatory review before commercial marketing (pharmaceuticals, medical devices, animal drugs, food additives, color additives). PTE must be applied for within 60 days of first FDA approval, and it is not automatic. The maximum PTE is 5 years, and the remaining patent term after PTE cannot exceed 14 years from the date of approval (whichever is shorter). Only one patent can receive PTE per FDA-approved product. PTA and PTE can both apply to the same patent — they are cumulative — but each has its own calculation and rules.

How do I challenge a USPTO error in my PTA calculation?

The USPTO's PTA calculation can be wrong — and errors are common enough that specialized law firms focus entirely on PTA recovery. To challenge a PTA calculation: (1) Within 2 months of patent issuance, file a PTA Request for Reconsideration with the USPTO. The request must specifically identify the alleged error and provide a corrected calculation. (2) If the USPTO denies the request, the patent owner can appeal to the Director of the USPTO within 63 days. (3) If still denied, the patent owner can file a civil action in the US District Court for the District of Columbia under 35 U.S.C. § 154(b)(4). Courts have ordered the USPTO to correct PTA calculations in numerous cases. Common errors include: misclassifying applicant delay, miscounting B delay when RCEs are filed, and failing to give credit for partially overlapping A and B delays. The financial stakes are high — each day of PTA on a blockbuster pharmaceutical patent is worth millions of dollars.

How do I apply for Patent Term Extension (PTE) for an FDA-approved drug?

PTE applications must be filed with the USPTO within 60 days of FDA approval of the product. The 60-day window is absolute — missing it means no PTE, regardless of the reason. To apply: (1) Identify the eligible patent: the patent must claim the approved product or a method of using or manufacturing it, and must not have already received PTE. (2) File the PTE application (patent application form PTO/SB/440 or equivalent) with the USPTO, identifying the patent, the FDA approval date, the regulatory review period calculation, and the requested extension. (3) The USPTO reviews eligibility and consults with the relevant federal agency (FDA for drugs, USDA for animal products) to determine the regulatory review period. (4) After publication of a notice in the Federal Register, third parties have 180 days to submit objections. PTE can extend the effective patent life by up to 5 years for the approved product (and equivalent products), but the remaining term after PTE cannot exceed 14 years from FDA approval.

Can both PTA and PTE apply to the same patent?

Yes, PTA and PTE can both apply to the same patent — they are cumulative. A pharmaceutical patent might receive, for example, 18 months of PTA (for USPTO prosecution delays) plus 3 years of PTE (for FDA regulatory review time). The total term of the patent would then be the base 20 years + 18 months PTA + 3 years PTE = approximately 24.5 years from the filing date. However, the remaining term after PTE cannot exceed 14 years from the date of FDA approval, which can act as a cap. The specific calculation is complex and should be verified with a patent attorney specializing in pharmaceutical patent law, especially for blockbuster drugs where each additional day of exclusivity is worth tens of millions of dollars.