510(k) RTA: How to Avoid FDA Refuse to Accept

What is RTA?

Refuse to Accept (RTA) is FDA's administrative screening process for 510(k) submissions. Before substantive review begins, FDA checks whether your submission is complete and properly formatted.

Key facts: - RTA screening takes 15 calendar days - ~43% of 510(k)s receive RTA letters (FDA data) - An RTA means your submission is rejected without review - You must correct deficiencies and resubmit

An RTA is not a rejection on the merits. It means your submission is missing required elements or has formatting issues that prevent review.

Top Reasons for RTA

Based on FDA's published RTA criteria and industry data, these are the most common deficiencies:

1. Missing or incomplete Indications for Use statement (23%) - Must match exactly what's on your labeling - Must specify patient population, condition treated, and anatomical location if applicable

2. Inadequate device description (18%) - Not enough detail to understand what the device is - Missing materials, dimensions, software version, or accessories

3. Predicate comparison issues (16%) - Predicate not clearly identified - No comparison table showing substantial equivalence - Predicate is not legally marketed

4. Missing performance data (14%) - Bench testing referenced but not included - Biocompatibility data missing or incomplete - Software documentation gaps (for SaMD)

5. Administrative deficiencies (12%) - Wrong cover letter format - Missing user fee - Truthful and Accuracy Statement not signed - eSTAR formatting errors

6. Labeling deficiencies (10%) - Draft labeling not included - Labeling doesn't match device description - Missing warnings or contraindications

The RTA Checklist

FDA publishes an RTA checklist for each submission type. Use it as your pre-submission audit.

Administrative elements: - Cover letter with device name, 510(k) number (if resubmission), and contact info - Truthful and Accuracy Statement (signed) - User fee payment confirmation - eSTAR format compliance (if electronic)

Device elements: - Indications for Use statement (FDA Form 3881) - Device description with materials, dimensions, and function - Predicate device identification with 510(k) number - Comparison table (your device vs. predicate)

Performance elements: - Bench testing data or reference to predicate data - Biocompatibility assessment (ISO 10993-1 risk assessment minimum) - Software documentation (if applicable) - Sterilization validation summary (if applicable)

Labeling elements: - Draft labeling including IFU, package label, and device label - Proposed labeling claims - Warnings and contraindications

Predicate Selection Mistakes

Predicate problems are a leading cause of RTA and substantive review issues:

Choosing the wrong predicate: - A cleared device is not automatically a valid predicate - The predicate must be legally marketed (not recalled, not subject to PMA conversion) - The predicate must have the same intended use and similar technological characteristics

Insufficient comparison: - "See predicate labeling" is not a comparison - You need a side-by-side table: intended use, technology, materials, performance - Differences must be explained with data supporting why they don't raise new safety/effectiveness questions

Multiple predicates without justification: - Using one predicate for intended use and another for technology is allowed - But you must explain the rationale clearly - "Split predicate" submissions get more scrutiny

What to Do If You Get an RTA

An RTA letter specifies exactly what's missing. Your options:

Option 1: Fix and resubmit - Address every deficiency cited - Reference the original 510(k) number in your cover letter - You do NOT start a new submission

Option 2: Request RTA review - If you believe the RTA was issued in error, you can request review - This is rare and usually unsuccessful — FDA's RTA criteria are objective

Option 3: Withdraw and rework - If the deficiencies are fundamental (wrong predicate, wrong pathway), withdraw - A 510(k) with unresolved RTA issues will get NSE'd at substantive review