Mac reinstalled, need file back

Odds are it's completely gone. Reinstalling usually involves a reformat and/or overwriting of existing data.

 

If it is important you can get it off a backup. If there is no backup, it's not important. If your having trouble with your backup maybe we can help you.

 

Taken literally, I wonder what that would mean. I think you mean you wiped it clean and installed the OS. Your file is gone. If you have a printed copy, make a new one.

 

While there is a chance that the file has been overwritten, the OS itself takes up only a small portion of the drive. If the file was elsewhere than where the install and temp files since then were, you may be able to use data recovery software to get it back. Try something like FileSalvage to get the deleted file back. You can use the demo to see if the file(s) can be recovered before you buy so if you find the file(s) are gone, you aren't out any money. Good luck. In the future as others have said, always make sure you backup before clean installing the OS. It's a painful lesson to learn.