Time Constraint: The 147-day period for authorization is shorter than the minimum 150- to 270-day review period for the De Novo classification pathway, which is required for initial LLM devices due to the lack of legal precedent.
Increased Depth of Review: Generative Artificial Intelligence (GenAI) systems are subject to a complex and in-depth review, with the Predetermined Change Control Plan (PCCP) published in August 2025 to manage unique risks such as "hallucinations" and "model drift."
High Risk Alert: The Digital Health Advisory Committee (DHAC) meeting in November 2025 increased oversight of LLMs, raising the possibility of extensive requests for additional information that would halt the review clock, particularly for high-risk applications.
Chance of Success: The only theoretical way to obtain authorization in this tight timeframe is if the application is submitted very early (before November 2025) and is a low-to-medium risk workflow optimization tool in areas like radiology, avoiding high-risk therapy claims.
To receive authorization by March 31, 2026 (i.e., within approximately 147 days), the LLM-based medical device must simultaneously meet the following critical requirements:
Some Details:
The Only Scenario That Will Achieve Approval: Low-Risk Workflow LLM
For an LLM device to receive approval within this tight timeline, it must navigate a very low-friction regulatory pathway and have an application already well advanced. The key requirements for this "Perfect Application" scenario are:
1. High-Quality and Early Filing (Timeliness)
Early Filing: The application must be submitted to the FDA before the forecast window opens on November 4, 2025, in early September or October 2025. The de novo pathway (mandatory pathway for new devices) has a minimum review time of 150 to 270 days. Meeting the 147-day deadline requires a review in near-record time with zero or very short pauses.
eSTAR Efficiency: The application must be submitted using the electronic application template (eSTAR), which became mandatory for De Novo applications starting October 1, 2025. This saves time by eliminating early-stage delays (RTA) in the review process due to application incompleteness.
2. Low-Risk Clinical Focus (Application Area)
Low Clinical Friction: The device should avoid high-risk diagnostic or therapeutic claims. Because the Digital Health Advisory Committee (DHAC) meeting in November 2025 focuses on high-consequence areas like digital mental health, LLMs in these areas will immediately be subject to additional review (Request for Additional Information (AI) and will miss the timeline.
Workflow Optimization: For the best chance of success, the LLM should be a tool used solely for workflow optimization (e.g., report drafting, summarizing patient history) in a field like radiology, where the FDA already has many traditional AI approvals. This will be seen as the least novel clinical intervention and minimize regulatory resistance.
3. Flawless Regulatory Compliance Process (Technology)
PCCP Preparation: The application must include a robust Predetermined Change Control Plan (PCCP) to manage the LLM's continuous learning and adaptation, in accordance with guidance finalized in August 2025. The FDA will rigorously review this methodology to ensure the safety and effectiveness of future changes to the model.
Zero Defects: Any "Request for Additional Information" (AI) received from the FDA during the review process stops the review clock and is not added to it. Therefore, for approval to occur by March 2026, the application must be nearly perfect the first time and have no significant flaws that would stop the review clock.
In summary, there is a chance, but only if a company (probably already experienced in radiology) has submitted the application months in advance, has applied for a low-risk workflow application, and has perfectly met all the new regulatory requirements (such as PCCP) necessary to manage the complex nature of the LLM.
Why do you think you're right?
Time Constraint: The 147-day period for authorization is shorter than the minimum 150- to 270-day review period for the De Novo classification pathway, which is required for initial LLM devices due to the lack of legal precedent.
Increased Depth of Review: Generative Artificial Intelligence (GenAI) systems are subject to a complex and in-depth review, with the Predetermined Change Control Plan (PCCP) published in August 2025 to manage unique risks such as "hallucinations" and "model drift."
High Risk Alert: The Digital Health Advisory Committee (DHAC) meeting in November 2025 increased oversight of LLMs, raising the possibility of extensive requests for additional information that would halt the review clock, particularly for high-risk applications.
Chance of Success: The only theoretical way to obtain authorization in this tight timeframe is if the application is submitted very early (before November 2025) and is a low-to-medium risk workflow optimization tool in areas like radiology, avoiding high-risk therapy claims.
* https://www.complizen.ai/post/de-novo-fda-pathway-complete-guide
* https://www.complizen.ai/post/samd-510k-vs-denovo-vs-pma
* https://www.jdsupra.com/legalnews/fda-s-digital-health-advisory-committee-2069955/
* https://www.psychiatrictimes.com/view/fda-committee-meets-on-generative-ai-digital-mental-health-devices
* https://www.fda.gov/regulatory-information/search-fda-guidance-documents/marketing-submission-recommendations-predetermined-change-control-plan-artificial-intelligence
* https://www.raps.org/news-and-articles/news-articles/2025/11/medical-groups-make-recommendations-for-fda-regula
* https://intuitionlabs.ai/articles/ai-radiology-trends-2025
Why might you be wrong?
To receive authorization by March 31, 2026 (i.e., within approximately 147 days), the LLM-based medical device must simultaneously meet the following critical requirements:
Some Details:
The Only Scenario That Will Achieve Approval: Low-Risk Workflow LLM
For an LLM device to receive approval within this tight timeline, it must navigate a very low-friction regulatory pathway and have an application already well advanced. The key requirements for this "Perfect Application" scenario are:
1. High-Quality and Early Filing (Timeliness)
Early Filing: The application must be submitted to the FDA before the forecast window opens on November 4, 2025, in early September or October 2025. The de novo pathway (mandatory pathway for new devices) has a minimum review time of 150 to 270 days. Meeting the 147-day deadline requires a review in near-record time with zero or very short pauses.
eSTAR Efficiency: The application must be submitted using the electronic application template (eSTAR), which became mandatory for De Novo applications starting October 1, 2025. This saves time by eliminating early-stage delays (RTA) in the review process due to application incompleteness.
2. Low-Risk Clinical Focus (Application Area)
Low Clinical Friction: The device should avoid high-risk diagnostic or therapeutic claims. Because the Digital Health Advisory Committee (DHAC) meeting in November 2025 focuses on high-consequence areas like digital mental health, LLMs in these areas will immediately be subject to additional review (Request for Additional Information (AI) and will miss the timeline.
Workflow Optimization: For the best chance of success, the LLM should be a tool used solely for workflow optimization (e.g., report drafting, summarizing patient history) in a field like radiology, where the FDA already has many traditional AI approvals. This will be seen as the least novel clinical intervention and minimize regulatory resistance.
3. Flawless Regulatory Compliance Process (Technology)
PCCP Preparation: The application must include a robust Predetermined Change Control Plan (PCCP) to manage the LLM's continuous learning and adaptation, in accordance with guidance finalized in August 2025. The FDA will rigorously review this methodology to ensure the safety and effectiveness of future changes to the model.
Zero Defects: Any "Request for Additional Information" (AI) received from the FDA during the review process stops the review clock and is not added to it. Therefore, for approval to occur by March 2026, the application must be nearly perfect the first time and have no significant flaws that would stop the review clock.
In summary, there is a chance, but only if a company (probably already experienced in radiology) has submitted the application months in advance, has applied for a low-risk workflow application, and has perfectly met all the new regulatory requirements (such as PCCP) necessary to manage the complex nature of the LLM.
* https://www.fda.gov/medical-devices/how-study-and-market-your-device/estar-program
* https://www.complizen.ai/post/de-novo-fda-pathway-complete-guide
* https://www.complizen.ai/post/samd-510k-vs-denovo-vs-pma