According to 21 CFR 807.81(a)(3), a new complete 510(k) application is required for changes or modifications to an existing device, where the modifications could significantly (likely to have a huge effect) affect the safety or effectiveness of the device, or the device is to be marketed for a new or different indication.

When a 510(k) holder decides to modify an existing device, the holder must decide whether the proposed device modification(s) requires submission of a 510(k). It is not FDA's intent that a 510(k) must be submitted for every modification. However, all changes in indications for use require the submission of a 510(k). A change in indication for use includes prescription use to over the counter use. Deciding When to Submit a 510(k) for a Change to an Existing Device provides guidance to 510(k) holders on deciding when to submit a 510(k) for a change to an existing device.

Examples of modifications that may require a 510(k) submission include, but are not limited to, the following:[1]

  • Sterilization method
  • Control Mechanism. The manner by which the actions of a device are directed. An example of a change in control mechanism would be the replacement of an electro-mechanical control with a microprocessor control.
  • Structural material
  • Manufacturing method
  • Operating parameters or conditions for use. An example of a change in operating principle would be using a new algorithm to compress images in a picture archiving and communications system. For an IVD, an example would be a change from immunofluorescence to ELISA.
  • Patient or user safety features (ergonomics). The way in which the device and the patient/user are intended to interact. Examples of this would be the various audible or visible alarms intended to alert the user to a hazardous condition, the layout of a control panel, or the mode of presentation of information to the user.
  • Sterile barrier packaging material
  • Stability or expiration claims. The date beyond which there are no data to assure that the product may perform safely or effectively and beyond which the manufacturer states the product should not be used.
  • Energy Type or Character. The type of power input to or output from the device. Examples of a change in energy type or character would be a change from AC to battery power (input) or a change from ionizing radiation to ultrasound to measure a property of the body (output). Note that this type of change does not include a change from 3V to 9V operation or a change from NICad to lead acid storage batteries. Also, adding an additional ground wire (a redundant ground) in parallel with the power cord safety ground is not considered a significant modification to a medical device. Lastly, when in doubt you can always contact the FDA directly for further guidance and clarification to "what is or isn't considered a modification"?
  • Software. The set of instructions used to control the actions or output of a medical device, to provide input to or output from a medical device, or to provide the actions of a medical device. This definition includes software that is imbedded or permanently a part of a medical device, software that is an accessory to a medical device, or software that is itself a medical device.
  • Labels. An example of modified Precautions and Warnings signs or labels.
  • Environmental Specifications. Examples of changes in environmental specifications are expanding the acceptable temperature range in which the device will operate properly or hardening the device to significantly higher levels of electromagnetic interference.

FDA believes that the 510(k) holder is best qualified to determine when modifications to their device could significantly affect safety or effectiveness. Therefore, every modification to the device should be reviewed by appropriate personnel to determine if it affects safety or efficacy. Any design or labeling change to a device should be evaluated and documented in accordance with the 21 CFR 820, Quality System regulation. If it is determined that the modification is not significant, the basis for this decision should be documented with supporting data in the 510(k) holder's device master file. If it is determined that the modification is significant, a new 510(k) must be submitted to FDA.

There are no provisions for a 510(k) amendment or supplement to the existing 510(k). A new 510(k) must be submitted. However, FDA developed a streamlined 510(k) process for modifications to a device cleared under 510(k), called the Special 510(k).


  1. Alpert, Susan., Ph.D., M.D."Deciding When to Submit a 510(k) for a Change to an Existing Device". January 10, 1997. [1]


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