Returning to Schengen Area Visa Questions

Upvote:4

As far as the maximum stay rule is concerned, you should be fine, for two reasons:

The rule is such that you only need 90 days (and not 180 days) between stays. It's a bit counterintuitive but if you left 91 days ago, the first day of your first 90-day stay is now exactly 181 days in the past and does not count anymore. So you have the right to stay for one day. The day after, the second day of your first stay is now out of the sliding window too (but the first day of your second stay counts!), so you still have exactly one day left. And so on until you reach 90 days again. With multiple stays, the whole thing can get confusing but fortunately there are calculators to help, see How does the Schengen 90/180 rule work?
The time spent under a long-stay visa (like your au-pair visa) is indeed excluded from the count. For more on that, see e.g. Does tourist visa (90 days) apply after a long-term visa ends in Schengen countries? You could even stay for 90 days immediately after the end of your long-stay visa or leave and re-enter the Schengen area during this time. Do carry any relevant documentation with you (au-pair visa, proof that you left the country, things about your status in the US or what you plan to do in Italy, etc.) in case there are questions but I would not expect any problem (don't volunteer anything, just have it ready if needed).

Relaxed 102681

Source: stackoverflow.com