Choosing Between a § 371 National Stage and a Bypass Continuation in U.S. PCT Practice

I.             Introduction

A PCT application designating the United States gives applicants a choice that does not exist in the same way in many other jurisdictions: enter the U.S. national stage under 35 U.S.C. § 371, or file a domestic U.S. application under 35 U.S.C. § 111(a) claiming benefit of the PCT application. Practitioners usually call the second route a bypass continuation.

That choice is a U.S.-specific product of continuation practice. Other major offices may provide divisionals, domestic-priority mechanisms, or early national or regional processing, but they generally require national or regional phase entry before a PCT-originating application can be prosecuted or divided in that office.[1]

This article is not a foreign-law comparison. The foreign-office point simply frames the U.S. issue: when U.S. counsel discusses a “bypass,” they are using a domestic prosecution concept. The working question is practical: when a PCT application designates the United States, what filing route best supports the intended U.S. claims, timing, priority record, and prosecution strategy?

The answer turns on filing basis, application identity, filing-date consequences, benefit and priority mechanics, copendency, new matter, restriction versus unity of invention, Track One eligibility, patent term, and patent term adjustment.

II.          The two U.S. routes

The conventional route is the U.S. national stage. An international application enters the national stage when the applicant files the documents and fees required by 35 U.S.C. § 371(c) within the time period set by 37 C.F.R. § 1.495. See 35 U.S.C. § 371(c); 37 C.F.R. § 1.495; MPEP § 1893.01(a)(1)[*]. In that route, the PCT application proceeds before the USPTO as the U.S. national-stage application.

The bypass route uses a different statutory structure. A regular national application filed under 35 U.S.C. § 111(a) may claim benefit of a prior international application designating the United States if the conditions of 35 U.S.C. §§ 120 and 365(c) and 37 C.F.R. § 1.78(d) are satisfied. The USPTO guidance states that, rather than submitting a national-stage application under § 371, an applicant may file a continuation, divisional, or continuation-in-part of the international application under § 111(a). MPEP § 1895.01. (USPTO)

A useful shorthand is this: § 371 continues the PCT into the U.S. national stage; a bypass creates a domestic child application. That shorthand should not replace the statutory analysis, but it helps avoid many filing and docketing errors.

III.      Quick comparison table

Issue	§ 371 National Stage	Bypass Continuation
Filing basis	35 U.S.C. § 371; 37 C.F.R. § 1.495	35 U.S.C. § 111(a); 37 C.F.R. § 1.53(b)
Application identity	The PCT application enters the U.S. national stage	A new U.S. domestic application claims benefit of the PCT
Filing date	International filing date for most legal purposes. See 35 U.S.C. § 363; MPEP § 1893.03(b).	Date the § 111(a) specification is received by the USPTO. See 35 U.S.C. § 111(a); 37 C.F.R. § 1.53(b); MPEP § 1896(I).
Benefit date	Not a benefit claim to the same PCT; the national-stage filing date is the international filing date	Properly supported claims may receive benefit of the PCT filing date under §§ 120 and 365(c)
Primary timing risk	30-month national-stage requirements, especially basic national fee and required copy. See 37 C.F.R. § 1.495(b).	Copendency and proper domestic benefit claim. See 35 U.S.C. § 120; 37 C.F.R. § 1.78(d).
Foreign priority	Usually handled through the international phase and IB priority-document transmission	Must be claimed in the bypass application itself. See 37 C.F.R. § 1.55; MPEP § 1895.01.
Restriction / unity	Unity of invention. See 37 C.F.R. §§ 1.475, 1.499; MPEP § 1893.03(d).	U.S. restriction practice. See 37 C.F.R. §§ 1.141–1.146; MPEP § 1896(III).
Track One at initial filing	Not available at national-stage entry; possible later with proper RCE	Potentially available at filing if Track One requirements are met. See 37 C.F.R. § 1.102(e); MPEP § 708.02(b)(I)(B).
New matter	New matter may not be added. See 35 U.S.C. § 132(a); 37 C.F.R. § 1.121(f).	Continuation should not add new matter; CIP may add matter, but later-added subject matter has later effective filing date
Patent term	Generally 20 years from international filing date for post-June 8, 1995 applications	Generally 20 years from parent international filing date if § 365(c) benefit is claimed. See 35 U.S.C. § 154(a)(2); MPEP § 2701(II).
PTA	Measured using national-stage commencement under § 371(b) or (f) for key PTA periods	Measured from § 111(a) filing date for key PTA periods. See 35 U.S.C. § 154(b); 37 C.F.R. § 1.703(a), (b).

IV.       Filing date, benefit date, and patent term

The filing-date issue is often the first place where the two routes diverge.

For a U.S. national-stage application, 35 U.S.C. § 363 provides that an international application designating the United States has the effect, from its international filing date, of a national application regularly filed in the USPTO. USPTO guidance emphasizes that the national-stage entry date is often confused with the filing date; the filing date of the international-stage application is also the filing date for the national-stage application. MPEP § 1893.03(b). (USPTO)

A bypass continuation filed under § 111(a) has its own U.S. filing date—generally, the date the specification is received by the USPTO. See 35 U.S.C. § 111(a); 37 C.F.R. § 1.53(b); MPEP § 1896(I). If the benefit claim is proper, claims supported by the PCT disclosure may receive the benefit of the PCT filing date under §§ 120 and 365(c). See 35 U.S.C. §§ 120, 365(c); 37 C.F.R. § 1.78(d). The support inquiry remains claim-specific: the earlier application must disclose the later-claimed invention in the manner required by § 112(a), other than best mode. See 35 U.S.C. § 112(a); MPEP § 211.

That distinction tends to matter when the U.S. claim set has moved away from the PCT claims. A bypass continuation may be entitled to the PCT filing date for one claim set but not for another. The continuation label does not answer the written-description question.

Patent term is related but distinct. For a continuation or CIP claiming benefit under § 365(c) of an international application designating the United States, the patent term generally runs from the filing date of the parent international application, not from the later bypass filing date. See 35 U.S.C. § 154(a)(2), (a)(3); MPEP § 2701(II). (USPTO)

V.          Timing: 30 months versus copendency

The national-stage route is built around the 30-month deadline. To avoid abandonment as to the United States, the applicant must, by 30 months from the priority date, provide the required copy of the international application if needed and pay the basic national fee. See 35 U.S.C. § 371(c); 37 C.F.R. § 1.495(b). The rule states that the relevant 30-month period may not be extended, and the USPTO guidance emphasizes that the basic national fee cannot be paid after the deadline with a surcharge. 37 C.F.R. § 1.495(a), (b), (h); MPEP § 1893.01(a)(1). (USPTO)

The bypass route has a different failure mode: copendency. To obtain benefit under §§ 120 and 365(c), the later § 111(a) application must include the required specific reference, be copending with the prior international application, and have at least one inventor in common. See 35 U.S.C. §§ 120, 365(c); 37 C.F.R. § 1.78(d); MPEP § 1895.01. (USPTO)

A familiar problem arises near the 30-month date. Before the deadline, the applicant may still have both options. After the deadline, the bypass route may be unavailable if the PCT application has become abandoned as to the United States and no timely U.S. national-stage or other continuing application preserves copendency. See 35 U.S.C. § 120; MPEP § 1895.01.

The docketing point is direct: a bypass can be a strategic route, but it should not be treated as a generic cure for a missed national-stage deadline.

VI.       Priority and benefit claims

Priority and benefit claims are a frequent source of bypass errors because the two routes use different mechanics.

In a U.S. national-stage application, the foreign priority claim is ordinarily made during the international phase. If the International Bureau supplies the priority document to the USPTO, that may satisfy the certified-copy requirement for the national-stage application. See 35 U.S.C. §§ 119(a)–(d), 365(b); 37 C.F.R. § 1.55(f)(2); MPEP §§ 1893.03(c), 1896(II). The MPEP contrasts that practice with § 111(a) priority practice, under which the priority claim and certified-copy timing are governed by 37 C.F.R. § 1.55. MPEP § 1896(II). (USPTO)

A bypass continuation requires domestic-application discipline. For post-AIA applications, the specific reference to the prior international application must be made in an application data sheet. See 37 C.F.R. § 1.78(d)(2). The ADS should identify the international application number, international filing date, and relationship—continuation, divisional, or continuation-in-part. MPEP § 1895.01.

Foreign priority must also be claimed in the bypass application itself. The MPEP states that a foreign priority claim under § 119(a)–(d) must be made in the continuing application regardless of whether that claim was made in the parent international application. MPEP § 1895.01; see also 35 U.S.C. § 119; 37 C.F.R. § 1.55.

A bypass application can therefore have a proper domestic benefit claim to the PCT application but still have a defective or missing foreign priority claim. Those are different claims, governed by different rules.

VII.   New matter and claim drafting

Neither route permits new matter to be added without consequence.

A § 371 national-stage application proceeds on the PCT disclosure. New matter may not be added to the disclosure. See 35 U.S.C. § 132(a); 37 C.F.R. § 1.121(f). If the PCT was filed in a non-English language, the U.S. national-stage translation should not be used as a vehicle for substantive edits; corrections and amendments should be handled through the proper procedures. See 37 C.F.R. §§ 1.121, 1.495(c); MPEP § 1893.01(d).

A bypass continuation gives counsel more control over the U.S. application package, but a true continuation should still be supported by the parent disclosure. The benefit claim does not rescue unsupported claim language. If the commercial embodiment changed after the PCT filing, counsel should decide whether the new material belongs in a separate application, a CIP, or a continuation with carefully limited claims.

A bypass CIP may be attractive when post-PCT data, examples, embodiments, or fallback positions are valuable. But claims supported only by added material receive the later CIP filing date and may face intervening prior art. See 35 U.S.C. §§ 102, 112, 120; MPEP §§ 201.08, 211.05.

The strategic fork is not simply “national stage or bypass.” It is whether the U.S. case should preserve the PCT disclosure cleanly, repackage the same disclosure for U.S. practice, or deliberately add later-developed subject matter with the priority consequences that follow.

VIII.                  Unity of invention versus U.S. restriction practice

The selected route determines the framework for multiple-invention practice. A § 371 national-stage application is examined under unity of invention principles. A bypass continuation filed under § 111(a) is subject to ordinary U.S. restriction practice. See 37 C.F.R. §§ 1.141–1.146, 1.475, 1.499; MPEP §§ 1893.03(d), 1896(III). The MPEP identifies this as one of the key differences between § 111(a) applications and § 371 national-stage applications. (USPTO)

That difference can matter. In some cases, unity may help keep related claims together longer than ordinary U.S. restriction practice would. In others, U.S. restriction practice may be more familiar and easier to plan around. The right question is not which standard is abstractly better, but which standard fits the intended U.S. claim set.

Counsel should look at the claims before selecting the route, particularly where the PCT includes multiple independent inventive concepts, product-and-method claims, apparatus-and-use claims, or several species.

IX.       Fees, translations, and filing formalities

The fee frameworks are different. A § 111(a) application is subject to the ordinary U.S. filing-fee rules in 37 C.F.R. § 1.16. A § 371 national-stage application is subject to the national-stage fee rules in 37 C.F.R. § 1.492. See 37 C.F.R. §§ 1.16, 1.492; MPEP § 1896(IV). (USPTO)

The more important issue is often the consequence of an omission. In a national-stage case, the basic national fee and required copy of the international application, if needed, must be handled by the 30-month deadline. See 37 C.F.R. § 1.495(b), (h); MPEP § 1893.01(a)(1). In a § 111(a) filing, missing-parts practice is different, but filing-date objectives, Track One requirements, or client-driven timing may impose their own constraints.

Translation strategy also differs. If the PCT was filed in a non-English language, national-stage entry raises translation-compliance issues. A bypass filed under § 111(a) may allow counsel to prepare a U.S.-style English specification rather than merely translate the PCT document, but drafting freedom should be exercised carefully. Edits that improve clarity are useful; edits that alter support may create priority problems.

X.          Track One and accelerated prosecution

Track One is one of the clearest practical reasons to consider a bypass continuation.

A newly filed utility or plant application under § 111(a), including a continuing application, may be eligible for Track One if the requirements of 37 C.F.R. § 1.102(e) are satisfied. See 37 C.F.R. § 1.102(e)(1); MPEP § 708.02(b)(I)(B). By contrast, applications entering the national stage under § 371 are not eligible for Track One at the time of entry. The MPEP states that an applicant who filed an international application may participate by filing a bypass continuation under § 111(a) claiming benefit under § 365(c), rather than entering the national stage under § 371. MPEP § 708.02(b)(I)(B). (USPTO)

A national-stage application may become eligible for prioritized examination in connection with a proper RCE, but that is later and procedurally different. See 37 C.F.R. §§ 1.102(e)(2), 1.114; MPEP § 708.02(b)(I)(A), (I)(C). For a client launching a product, seeking investment, or needing early claim clarity, the timing difference can affect portfolio sequencing and continuation strategy.

XI.       Patent term adjustment

Patent term adjustment deserves a separate look because the filing route can affect the PTA framework even when it does not change the ordinary 20-year patent term.

For PTA, the fourteen-month first-action period is measured from the filing date under § 111(a) for a bypass application, but from national-stage commencement under § 371(b) or § 371(f) for a national-stage application. See 35 U.S.C. § 154(b)(1)(A)(i); 37 C.F.R. § 1.703(a)(1); MPEP § 2731. Similarly, the three-year pendency provision is measured from the § 111(a) filing date or the § 371 national-stage commencement date, depending on the route. See 35 U.S.C. § 154(b)(1)(B); 37 C.F.R. § 1.703(b); MPEP § 2731. (USPTO)

The PTA analysis should be done with the actual filing facts in hand: when national-stage requirements were satisfied, whether early processing was requested, when the bypass was filed, and whether prosecution delay is commercially relevant. The route selection should not be reduced to a simplistic patent-term assumption.

XII.   When § 371 may fit the case

A § 371 national-stage application may fit when the PCT package is already the package the applicant wants to prosecute in the United States. That is common when the disclosure is settled, the claims were drafted with the U.S. market in mind, and the applicant does not need Track One at initial filing.

National stage may also be attractive where unity of invention is expected to align with the claim strategy, where priority documents and international-stage formalities are clean, or where the client’s global docketing process treats U.S. entry as part of a broader national-phase campaign.

The question is not whether § 371 is better in the abstract. It is whether the applicant wants continuity of the PCT record without the extra domestic-benefit mechanics of a bypass filing.

XIII.                  When bypass may be worth considering

A bypass continuation may be worth considering when the applicant wants the U.S. case to behave like a domestic continuing application from day one. Common reasons include Track One eligibility at filing, U.S.-style claim restructuring, desire for ordinary restriction practice, or a CIP strategy involving later-developed subject matter.

Bypass practice can also be useful when the PCT was drafted for international compromise and the U.S. case needs a sharper domestic presentation. The housekeeping burden, however, is real: copendency, ADS benefit claims, foreign priority claims, translations, and written-description support all need deliberate review.

Counsel should be especially cautious with bypass filings prepared under deadline pressure. The route is flexible, but it is not forgiving of a defective benefit chain.

XIV.                   Common pitfalls

The recurring mistakes are predictable.

First, practitioners sometimes use “national phase” as shorthand for any U.S. filing based on a PCT. That shorthand is harmless in conversation until it appears in filing instructions, ADS data, or client reporting.

Second, applicants may file a bypass without a proper ADS benefit claim. For post-AIA applications, the specific reference required by 37 C.F.R. § 1.78(d)(2) must be in the ADS. See MPEP § 1895.01.

Third, applicants may assume that the PCT’s foreign priority claim automatically carries into the bypass. It does not. The bypass needs its own foreign priority claim under 37 C.F.R. § 1.55. See MPEP §§ 1895.01, 1896(II).

Fourth, a bypass filed after the PCT has become abandoned as to the United States may fail for lack of copendency. See 35 U.S.C. § 120; MPEP § 1895.01.

Fifth, applicants may add new matter while continuing to treat all claims as if they were entitled to the PCT filing date. That is a priority problem waiting to happen.

These are ordinary docketing and drafting errors caused by treating the two routes as interchangeable.

XV.   Conclusion

A § 371 national-stage application and a bypass continuation can both bring PCT-originating subject matter before the USPTO, but they serve different prosecution objectives.

The § 371 route often fits when the applicant wants ordinary U.S. national-stage treatment of the PCT application. The bypass route often deserves consideration when the applicant wants domestic continuation practice, Track One at filing, U.S.-specific claim restructuring, or a CIP strategy.

The better question is not, “Which route is generally better?” It is, “Which route best supports the U.S. claims we intend to pursue, on the timeline the client needs, with the cleanest priority and benefit record we can create?”

Where the answer is not obvious, the decision should be made before the 30-month deadline, with the ADS, priority claim, translation, and claim-support issues reviewed as part of the filing strategy—not cleaned up after the fact.

Notes

[*] Citation convention: Statutes and rules are cited as legal authority. The MPEP is cited as USPTO examination guidance. Unless otherwise indicated, MPEP citations are to MPEP, 9th ed., Rev. 01.2024 (published Nov. 2024; current through Jan. 31, 2024). The USPTO’s MPEP landing page states that Rev. 01.2024 was published in November 2024 and is current through January 31, 2024; later USPTO policy and procedure changes are not incorporated in that revision.

[1] See Guidelines for Examination in the European Patent Office pt. A-IV, § 1.1 (2026) (stating that, where the earlier application is a Euro-PCT application, a divisional may be filed only upon effective European-phase entry); Japan Patent Office, PCT International Applications (Mar. 25, 2026) (describing Japan’s 30-month national-phase and translation requirements); WIPO, PCT Applicant’s Guide—Republic of Korea, Summary of Requirements for Entry into the National Phase (valid from June 1, 2026) (listing 31-month national-phase deadlines); WIPO, PCT Applicant’s Guide—China, Summary of Requirements for Entry into the National Phase (valid from Apr. 16, 2026) (describing Chinese national-phase practice).