ANDA Filing Requirements: What FDA Expects in Your Generic Drug Application
An ANDA filing requires Form FDA 356h, GDUFA user fee payment and cover sheet, chemistry/manufacturing/controls (CMC) data for drug substance and drug product, bioequivalence study reports, labeling with annotated comparison to the reference listed drug (RLD), patent certifications for all Orange Book-listed patents, environmental assessment or categorical exclusion claim, debarment certification, financial disclosure statements, and any Drug Master File (DMF) authorization letters. All content must be submitted electronically in eCTD format per 21 CFR 314.94.
Key Takeaways
Key Takeaways
- Every ANDA must include Form FDA 356h, GDUFA cover sheet with fee payment, CMC data, bioequivalence study reports, annotated labeling comparison to the RLD, and patent certifications for all Orange Book-listed patents
- CMC data requires at least 12 months of long-term stability and 6 months of accelerated stability on a minimum of 3 batches at the time of submission
- Paragraph IV patent certifications require notice to the NDA holder and patent owner within 20 days of FDA acceptance, including a detailed factual and legal basis for the invalidity/non-infringement opinion
- Most ANDAs qualify for categorical exclusion from environmental assessment under 21 CFR 25.31(a)
- ANDA filing requirements are codified in 21 CFR 314.94, which specifies every element FDA expects in an abbreviated new drug application. Missing or incomplete elements are the primary driver of refuse-to-receive decisions and complete response letters from the Office of Generic Drugs (OGD).
- Generic drug manufacturers face a precise set of documentation requirements that differ substantially from the NDA pathway. While ANDAs do not require clinical efficacy data, they demand rigorous chemistry, bioequivalence, labeling, and patent certification documentation. Understanding exactly what FDA expects in each section of the ANDA reduces review cycles and accelerates time to approval.
- In this guide, you'll learn:
- Every required section of an ANDA under 21 CFR 314.94
- How to complete Form FDA 356h for generic drug applications
- CMC data requirements for drug substance and drug product
- Bioequivalence study report specifications
- Patent certification obligations and how to address Orange Book listings
- DMF reference requirements and right-of-reference procedures
- Environmental assessment and user fee requirements
- Related guides:
- ANDA submission process
- Bioequivalence study requirements
- Drug Master File guide
- FDA Orange Book guide
- Paragraph IV certification guide
- GDUFA user fees guide
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Form FDA 356h: The Application Cover Form
Form FDA 356h is the mandatory application form for all drug applications submitted to CDER, including ANDAs. It serves as the cover form that identifies the applicant, the drug product, the type of submission, and the certifications required under federal law.
Form 356h must be completed in full for every original ANDA submission. Incomplete or incorrectly completed forms are a frequent refuse-to-receive trigger.
Required Information on Form 356h for ANDAs
| Section | Required Information |
|---|---|
| Applicant information | Legal name, address, establishment registration number |
| Application type | Check "ANDA" (505(j)) |
| Drug product details | Established name, proprietary name (if any), dosage form, route, strength |
| Reference listed drug | RLD name, NDA/ANDA number, applicant name |
| Submission type | Original application, amendment, or supplement |
| Cross-references | DMF numbers, referenced applications |
| Certifications | Debarment, financial disclosure, field copy, patent certifications |
| Signature | Authorized representative signature and date |
Critical Form 356h requirements specific to ANDAs:
- The RLD must be identified by its NDA number and approved dosage form/strength
- The applicant must certify compliance with debarment provisions under 21 USC 335a
- Financial disclosure or certification per 21 CFR Part 54 must be provided for all clinical investigators who conducted BE studies
- The application must identify all manufacturing sites, including contract manufacturers
FDA periodically updates Form 356h. Always use the current version from FDA.gov. Submitting an outdated version does not trigger RTR but creates processing delays. As of early 2026, FDA accepts both the standard and electronic versions of Form 356h.
GDUFA Cover Sheet and User Fee Payment
Under the Generic Drug User Fee Amendments, every original ANDA submission must be accompanied by a GDUFA cover sheet and evidence of user fee payment.
GDUFA Cover Sheet Requirements
The GDUFA cover sheet is a separate document from Form 356h. It must include:
- GDUFA facility identification number (FEI) for each manufacturing facility
- User fee payment identification number
- Applicant name and DUNS number
- Indication of whether a fee waiver or reduction is being requested
Fee Payment Process
| Step | Action |
|---|---|
| 1 | Create an account in FDA's Generic Drug User Fee Cover Sheet system |
| 2 | Generate the cover sheet with facility and payment information |
| 3 | Pay the ANDA application fee via Pay.gov |
| 4 | Include the cover sheet and payment confirmation in Module 1 of the eCTD submission |
Fee waiver provisions under GDUFA III:
- Small business fee waivers are available for the first ANDA submitted by applicants meeting small business criteria
- Fee waivers may be granted for applicants with gross revenues under $8 million in the preceding fiscal year
- Orphan drug ANDAs may qualify for reduced fees
- Fee waiver requests must be submitted to OGD before or concurrent with the ANDA
FDA's published FY 2026 GDUFA rates include an ANDA application fee of $358,247 and a Type II DMF fee of $102,584. Facility and program fees should be confirmed from FDA's current GDUFA fee schedule because they differ by facility and portfolio category.
Chemistry, Manufacturing, and Controls (CMC) Requirements
The CMC section represents the largest portion of most ANDA submissions and is the most common source of complete response letters. CMC data must demonstrate that the generic product is pharmaceutically equivalent to the RLD and manufactured under cGMP conditions.
Drug Substance Requirements (eCTD Module 3.2.S)
| Section | Required Information | Regulatory Reference |
|---|---|---|
| 3.2.S.1 | General information: nomenclature, structure, properties | 21 CFR 314.94(a)(5) |
| 3.2.S.2 | Manufacture: manufacturer(s), process description, controls | 21 CFR 314.94(a)(5) |
| 3.2.S.3 | Characterization: elucidation of structure, impurities | ICH Q6A |
| 3.2.S.4 | Control of drug substance: specifications, analytical procedures, validation | ICH Q6A, USP/NF |
| 3.2.S.5 | Reference standards: primary and secondary standards | USP General Chapter <11> |
| 3.2.S.6 | Container closure system: description and suitability | 21 CFR 211.94 |
| 3.2.S.7 | Stability: protocol, data, shelf life | ICH Q1A(R2) |
When referencing a Drug Master File (DMF):
If the drug substance information is maintained in a DMF, the ANDA applicant must:
- Provide a letter of authorization from the DMF holder granting right of reference
- Include the DMF number in Form 356h and in the eCTD cross-reference section
- Submit an applicant's portion summarizing the drug substance information available to the ANDA applicant
- The DMF holder must separately authorize FDA to reference the DMF (21 CFR 314.420)
Drug Product Requirements (eCTD Module 3.2.P)
| Section | Required Information | Regulatory Reference |
|---|---|---|
| 3.2.P.1 | Description and composition: qualitative and quantitative | 21 CFR 314.94(a)(5) |
| 3.2.P.2 | Pharmaceutical development: formulation rationale, component selection | ICH Q8(R2) |
| 3.2.P.3 | Manufacture: process description, batch formula, in-process controls | 21 CFR 211 Subpart F |
| 3.2.P.4 | Control of excipients: specifications and analytical methods | USP/NF, 21 CFR 211.84 |
| 3.2.P.5 | Control of drug product: specifications, methods, batch analysis | ICH Q6A |
| 3.2.P.6 | Reference standards | USP General Chapter <11> |
| 3.2.P.7 | Container closure system: description and suitability testing | 21 CFR 211.94 |
| 3.2.P.8 | Stability: long-term, accelerated, and in-use stability data | ICH Q1A(R2), Q1E |
Stability Data Requirements
FDA expects stability data at the time of ANDA submission sufficient to support the proposed shelf life:
| Condition | ICH Guideline | Minimum Data at Filing |
|---|---|---|
| Long-term (25C/60% RH) | Q1A(R2) | 12 months |
| Accelerated (40C/75% RH) | Q1A(R2) | 6 months |
| Intermediate (30C/65% RH) | Q1A(R2) | Required if accelerated fails |
- At least 3 batches are expected, with at least 1 at production scale or 100,000 units (whichever is larger) per FDA guidance
- Stability protocols must include all ICH Q1A(R2) parameters: appearance, assay, degradation products, dissolution, moisture (as appropriate)
- Proposed shelf life should be supported by available data or extrapolation per ICH Q1E
One of the most common CMC deficiencies in ANDAs is submitting fewer than 3 stability batches or insufficient time points. OGD typically expects at least 12 months of long-term data and 6 months of accelerated data at the time of original ANDA submission. Submitting with less data invites a complete response letter.
Bioequivalence Study Requirements
The bioequivalence (BE) section is the scientific foundation of an ANDA. It demonstrates that the generic product delivers the same rate and extent of drug absorption as the RLD, establishing therapeutic equivalence under 21 CFR Part 320.
Required BE Documentation
| Document | Content | Reference |
|---|---|---|
| BE study protocol | Study design, population, dosing, sampling, endpoints | 21 CFR 320.21 |
| Clinical study report | Complete study report per ICH E3 format | 21 CFR 320.21(c) |
| Bioanalytical method validation | Method development, validation per FDA guidance | FDA Guidance (2018) |
| Statistical analysis | 90% CI for AUC and Cmax (80-125% acceptance range) | 21 CFR 320.23 |
| Dissolution data | Comparative dissolution profiles (12 units each, 4 media) | FDA Guidance |
| Certificate of analysis | For both test and reference products used in BE study | 21 CFR 320.63 |
Standard In Vivo BE Study Design
Most ANDAs require an in vivo pharmacokinetic BE study with the following design elements:
- Study type: Single-dose, 2-period, 2-sequence crossover
- Population: Healthy adult volunteers (typically 24-48 subjects)
- Dosing: Highest strength, fasting and/or fed conditions per PSG
- Pharmacokinetic parameters: AUC0-t, AUC0-inf, Cmax, Tmax
- Statistical criteria: 90% confidence interval of the geometric mean ratio (test/reference) for log-transformed AUC and Cmax must fall within 80.00-125.00%
- Washout period: At least 5 half-lives between periods
BCS-Based Biowaivers
For certain drug products, in vitro dissolution data may substitute for in vivo BE studies under 21 CFR 320.22. FDA's BCS-based biowaiver guidance allows this for:
| BCS Class | Solubility | Permeability | Biowaiver Eligible |
|---|---|---|---|
| Class 1 | High | High | Yes (with rapid dissolution) |
| Class 3 | High | Low | Yes (with very rapid dissolution, per 2021 guidance) |
| Class 2 | Low | High | Generally no |
| Class 4 | Low | Low | No |
Requirements for a BCS-based biowaiver:
- Drug substance must meet BCS Class 1 or Class 3 criteria
- Drug product must be an immediate-release solid oral dosage form
- Drug product must exhibit rapid (Class 1) or very rapid (Class 3) dissolution
- Excipients should not affect absorption (for Class 3)
- Product must not have a narrow therapeutic index
Labeling Requirements for ANDAs
ANDA labeling must be the same as the RLD labeling, with limited exceptions. Labeling deficiencies account for approximately 18% of ANDA complete response letters, making this a critical filing requirement.
Required Labeling Documents
| Document | Description | Format |
|---|---|---|
| Draft labeling | Complete prescribing information, container label, carton label | Per 21 CFR 201 |
| Side-by-side comparison | Annotated comparison of proposed generic labeling vs. current RLD labeling | Redline format |
| Medication Guide (if applicable) | Must be same as RLD Medication Guide | Per 21 CFR Part 208 |
| Patient Package Insert (if applicable) | Must match RLD patient labeling | Per 21 CFR 201 |
Labeling "Sameness" Requirements
Under 21 CFR 314.94(a)(8), ANDA labeling must be the same as the RLD labeling except for:
Permitted differences:
- Trade name (generic must use established name per 21 CFR 299.4)
- Manufacturer name and address
- Expiration date and lot number
- Container size
- Section viii statement carve-outs (patented indications or methods of use)
- Removal of trade-name-specific information
Not permitted to differ:
- Active ingredient name and strength
- Indications and usage (except for section viii carve-outs)
- Dosage and administration
- Contraindications, warnings, precautions
- Adverse reactions
- Clinical pharmacology
Always pull the most current RLD labeling from DailyMed (dailymed.nlm.nih.gov) immediately before finalizing your ANDA labeling. RLD labeling can change during ANDA development. If your submitted labeling references an outdated version of the RLD labeling, OGD will issue a deficiency.
Section viii Statement (Labeling Carve-Out)
Under 21 CFR 314.94(a)(8)(iv), an ANDA applicant may omit from its labeling any indication or method of use that is protected by a method-of-use patent listed in the Orange Book. The applicant must include a "section viii statement" identifying the omitted information and the patent it seeks to avoid.
Requirements for a valid section viii carve-out:
- The carved-out indication must be protected by a method-of-use patent listed in the Orange Book
- The carve-out must not render the remaining labeling clinically meaningless
- The applicant must not promote the generic for the carved-out indication
- The proposed labeling must still be adequate for safe and effective use of the product
Patent Certifications Under 21 CFR 314.94(a)(12)
Every ANDA must include a patent certification or statement for each patent listed in the Orange Book for the RLD. This is one of the most legally consequential sections of the ANDA filing.
Certification Types and Requirements
| Certification | When Used | Required Documentation |
|---|---|---|
| Paragraph I | No patent listed in Orange Book | Statement to that effect |
| Paragraph II | Patent has already expired | Identification of expired patent |
| Paragraph III | ANDA applicant will wait for patent expiry | Patent number and expiration date |
| Paragraph IV | Patent is invalid, unenforceable, or not infringed | Detailed statement of factual and legal basis |
Paragraph IV Notice Requirements
If the ANDA includes a Paragraph IV certification, the applicant must send notice to:
- The NDA holder (per FDA records)
- Each patent owner identified in the Orange Book patent listing
Notice content requirements (21 CFR 314.95(c)):
- Identity of the patent(s) subject to Paragraph IV certification
- Detailed statement of the factual and legal basis for the applicant's opinion
- An offer of confidential access to the ANDA
- Notice must be sent by registered or certified mail, return receipt requested
Timing: Notice must be sent within 20 days of FDA's acceptance of the ANDA for filing.
Drug Master File (DMF) References and Right of Reference
Many ANDA applicants source drug substance from suppliers who maintain Drug Master Files (DMFs) with FDA. Properly referencing a DMF is essential for a complete ANDA filing.
DMF Reference Requirements
| Requirement | Details |
|---|---|
| Authorization letter | DMF holder must provide a written letter authorizing the ANDA applicant to reference the DMF |
| DMF number | Must be included in Form 356h and in Module 1 of the eCTD |
| Applicant's portion | ANDA applicant must submit an "open" summary of drug substance information in Module 3.2.S |
| Closed portion | DMF holder's confidential information reviewed directly by FDA |
| Annual update | DMF holder must keep the DMF current; outdated DMFs can delay ANDA review |
Right of Reference Under 21 CFR 314.3(b)
A right of reference is the authority to rely on an investigation or approval by another party. For ANDAs, right of reference is most commonly used for:
- Referencing a Type II DMF for drug substance information
- Referencing contract manufacturer data
- Referencing bioequivalence studies conducted by a third party
The right of reference letter must:
- Be signed by the DMF holder or authorized representative
- Identify the specific information being authorized for reference
- Identify the ANDA applicant and the specific ANDA by number (or "to be assigned")
- Be submitted to FDA by the DMF holder
Environmental Assessment Requirements
Under 21 CFR Part 25, ANDA applicants must address the National Environmental Policy Act (NEPA) requirements in their submission.
Categorical Exclusion
Most ANDA submissions qualify for categorical exclusion from the requirement to prepare an environmental assessment. Under 21 CFR 25.31(a), categorical exclusion applies to:
- ANDAs for drugs that are the same as already-approved drugs (which covers most ANDAs)
- Actions that do not individually or cumulatively have a significant effect on the human environment
To claim categorical exclusion, the ANDA must include:
- A statement citing the applicable categorical exclusion provision (21 CFR 25.31(a))
- A statement that no extraordinary circumstances exist that would require an environmental assessment
If the product is not eligible for categorical exclusion (rare for ANDAs), a full environmental assessment per 21 CFR 25.40 is required.
Additional Required Certifications and Statements
Debarment Certification (21 CFR 314.94(a)(11))
Every ANDA must include a certification that the applicant did not and will not use the services of any person debarred under Section 306 of the FD&C Act (21 USC 335a). This includes individuals convicted of felonies related to the generic drug approval process.
Financial Disclosure (21 CFR Part 54)
For each clinical investigator who conducted or supervised a BE study included in the ANDA, the applicant must submit either:
- Form FDA 3454: Certification that no financial interests or arrangements exist that could affect study outcome
- Form FDA 3455: Disclosure of financial interests or arrangements
Field Copy Certification
The applicant must certify that a complete copy of the ANDA has been submitted to the FDA district office responsible for the manufacturing site, enabling pre-approval inspection.
Complete ANDA Filing Checklist
| Section | Required Element | Regulatory Reference | Included? |
|---|---|---|---|
| Administrative | Form FDA 356h (completed and signed) | 21 CFR 314.94(a)(1) | |
| Administrative | GDUFA cover sheet and fee payment | GDUFA III | |
| Administrative | Debarment certification | 21 CFR 314.94(a)(11) | |
| Administrative | Financial disclosure (Forms 3454/3455) | 21 CFR Part 54 | |
| Administrative | Field copy certification | 21 CFR 314.94(a)(1) | |
| Administrative | Environmental assessment or categorical exclusion | 21 CFR Part 25 | |
| Patent | Patent certifications (Paragraphs I-IV) for all listed patents | 21 CFR 314.94(a)(12) | |
| Patent | Paragraph IV notice letters (if applicable) | 21 CFR 314.95 | |
| Labeling | Draft labeling | 21 CFR 314.94(a)(8) | |
| Labeling | Annotated side-by-side RLD comparison | 21 CFR 314.94(a)(8) | |
| Labeling | Medication Guide (if RLD has one) | 21 CFR Part 208 | |
| CMC | Drug substance data (or DMF reference with authorization) | 21 CFR 314.94(a)(5) | |
| CMC | Drug product formulation and manufacturing | 21 CFR 314.94(a)(5) | |
| CMC | Specifications and analytical methods | ICH Q6A | |
| CMC | Stability data (3 batches, 12-month long-term, 6-month accelerated) | ICH Q1A(R2) | |
| CMC | Container closure system information | 21 CFR 211.94 | |
| BE | Bioequivalence study report | 21 CFR Part 320 | |
| BE | Bioanalytical method validation | FDA Guidance (2018) | |
| BE | Dissolution data (comparative profiles) | FDA Guidance | |
| BE | Statistical analysis (90% CI, 80-125%) | 21 CFR 320.23 | |
| DMF | Authorization letters from DMF holders | 21 CFR 314.420 | |
| DMF | Applicant's portion (open section) | 21 CFR 314.420 |
References
The most common RTR triggers are administrative: unpaid GDUFA fees, missing Form 356h, absent patent certifications, or failure to include any bioequivalence data. These are threshold requirements that must be met for OGD to accept the application for substantive review. Scientific deficiencies (incomplete stability data, suboptimal BE study design) are addressed during review through information requests or complete response letters, not RTR.