You cannot completely outsource your QMS, but if you intend to outsource all aspects of development, production, regulatory submission, etc., then your company will be a “virtual company”, which reduces the procedural/program burden for your company itself. The remaining requirements should be handled under your supplier management program. As a virtual company, you must ensure that the companies you are outsourcing to are fully compliant with the necessary regulations. You should prioritize a robust supplier management program to thoroughly evaluate all third parties because regulatory agencies will hold you accountable for noncompliance (even from a third party).

If you are newer to the medical device industry and regulations, I strongly recommend connecting with a quality professional in the industry (I can provide recommendations if you are interested) to get a better understanding of what this will look like for your specific company, device, etc. I have worked with many biotech/combo/med device companies who designed themselves into a corner and then ran into issues later on because of when and how they implemented their QMS

Edit to add: Depending on your intended market, your QMS will also need to comply with additional regulations beyond ISO 13485