My "top contributor" rating disappeared from Yahoo Answers - why?

It's a static rating that changes from week to week based on your participation in a category.

Jump back in, ask and answer questions and it'll probably be back next week.

The badge is all about contribution/best answers in a category. Perhaps like me you have not been spending much time in your chosen category so the badge goes away, as mine has done as well. If you want to get it back then you will have to go back into your chosen category and answer some more questions and receive the best answers needed to get the badge back again.

I lost mine as well, once YA! picked up this new layout. It was gone, there one day, then gone again. Even though I've seen people with lower percentages of best answers in the same category I'm active in. I don't get it. :(

The TC designation is dynamic and can be removed if your percentage of BA and answers in a category drops below the Yahoo requirement. If that happens spend a little more time in that category answering questions and quite possibly you will regain the designation. http://help.yahoo.com/kb/index?page=content&id=SLN...

They come and go. It works according to the section you have been posting to, and the way your answers have been received by other posters.