Extended stays

If you're traveling on a US passport you do not need an extended stay visa unless you plan to stay more than 90 days. Longer than 90 days you will have to apply to France for an extended stay visa. Here is a thread from a few months ago, about half way down there is a post that includes a link to the French consulate and instructions for applying for that visa:

https://community.ricksteves.com/travel-forum/general-europe/a-different-twist-on-the-schengen-rule-question

If you're not a US citizen then the answer may be different.

Thanks! Looking ahead to retirement!

It is not easy to get long stay visas and you need to look on the French consulate site for your country to see what the requirements are. Basically you have to be not working there, have adequate financial resources which are proved by bank records and such, and show that you have health insurance that is equivalent to the insurance in France and provide evidence of housing. Health insurance is quite expensive and made more so by the fact that if you are a US citizen you need to keep paying for your medicare while abroad or else face much higher monthly charges when you return to the states. Comprehensive insurance at retirement age is expensive in Europe. We looked into it -- we had gotten a long stay visa for Italy earlier -- and decided we would just do long trips of 90 days or less rather than the longer stay. Another wrinkle if you are in the US. Most US medicare gap policies cover 60 days of emergency care internationally but not 90 so for 90 day trips you probably need to get travel medical insurance that includes emergency evacuation. We carry an annual policy with Medjet Assist that will fly us from a hospital abroad to a hospital near our home if necessary on the type of carrier appropriate to the medical condition. This is the sort of thing that can run 100K if you need expert care and so is worth insuring for even if you have coverage for emergency care. The cost of medical care is much less in France than the US and so you might not feel you need insurance for care for short stays, but the medical evacuation is something that needs to be covered as the cost is huge if you need it. The process is highly formalized and you need to get detailed instructions on the documents you need if you want to proceed.