Different requirements for Class II and Class III Medical Devices

Hi all, the company I work for is transitioning into the manufacture of class III medical devices. I'm just wondering what additional requirements there are other than PMA instead of 510k? Is there a document that compares both sets of requirements side by side? Thanks, your help would be appreciated.
In principle, the requirements of the QSR are the same for Class II and Class III devices. However you will get an inspection from FDA during the PMA process for a Class III device, whereas for a class II device, you will be placed on the routine inspection schedule. The most obvious difference for Class III devices is the need for very strict control of changes and the need to assess when FDA needs to be notified of process changes.

There are also a whole bunch of guidance documents here.
PMA Guidance Documents


Involved In Discussions
I"m going to assume that "like" means "yes." In that case, I concur with Chris and then some. The last Class I/II device company (not contract manufacturer) I saw try to take on Class IIIs...let's just say that did not have a happy ending.

It didn't seem to be the typical "they just won't listen," after numerous people tried to tell them, but that companies that have long experience with Class I/II simply have a hard time wrapping their minds around Class III, even if they want to. It can seem like you are dealing with a whole different FDA. Much more scrutiny, much less flexibility, much quicker to move to enforcement action.

If you were a device company, I'd advise you against it. However, if your responsibilities are limited to manufacturing, I will say tread with extreme caution. In particular, I would be very clear on the responsibilities you are inherently taking on under the QSR, and which ones you are agreeing to take on in your agreement with your client.

If you've been in this biz for more than 5 minutes, I'm sure you won't be shocked to hear that device companies, especially startups, frequently try to task out their legal responsibilities along with the contract work. In some cases, that just doesn't work, because the QSR is clear. In other cases, there can be some gray areas where the contract manufacturer can find itself on a hook it didn't know was there. Complaint management and investigation is an area I'd look very carefully at, along with responsibilities related to management review. And I'd make sure your client knows whatever you know, as soon as you know it.
Last edited:
I have to agree with Watchcat, FDA treat Class III devices and their manufacturers very differently from regular Class I or II. If you are not used to the level of scrutiny, it will come as a shock. If you are a contract manufacturer, make sure the quality agreements are very thorough and responsibilities well defined.

These days, a good ISO13485 compliant company should get through a FDA inspection for a Class II product without too much difficulty. For a Class III inspection, FDA will look for much more evidence, be very thorough when reviewing it, and take every clause in the QSR to the extreme. Its the same regulation, but taken to a whole new level.


Involved In Discussions
Which brings up another important issue...cost. The additional costs associated with Class III devices are truly insidious, in every dictionary sense of the word:

1a : having a gradual and cumulative effect : subtle
1b developing so gradually as to be well established before becoming apparent.
2a : awaiting a chance to entrap : treacherous.
2b : harmful but enticing

The additional costs will be hard to estimate up front, so you may end up pricing your services too low. Regardless, from a business perspective, all the changes you would have to make and the additional costs you would have to incur, just for one device? Might not be worth it....to you, even if the client is willing to pay a premium, or to the client. If this is a startup, they might not even know this. Or they might, and are looking for a Class I/II contract manufacturer that doesn't know this, and so will bid low.

PS Why does everyone always "have to" agree with me? Can't you just do it? :p

Top Bottom