Looked up a couple of your prior posts and you mention being married to a French woman. Normally, a married couple files in together as the tax system is based on "household" for married folks.
As a US citizen living in , you need to declare your worldwide income both to the IRS and to the French Fisc. There are treaty provisions to avoid being double taxed on the same income, but those are probably best explained by someone at the local tax office. Right now is the French tax filing season, so you may want to wait a month or so before heading to the tax office. But it may just be a matter of adding your information to a t declaration with your wife if she has already filed.
But whether or not you're married to a French person, if most or all of your income is retirement income coming from the US, chances are you won't owe much (or even any) tax to . The Avis d'Imposition you get after filing comes in handy for many istrative matters, however.