It’s getting closer to that time of the year in the US where everybody files their taxes with ‘Uncle Sam’. I don’t know how many people are like me and prefer to keep a copy of their forms that they fill-in from the IRS on their computer, but using Preview you cannot save the PDF directly.

However, you can save the PDF in it’s filled-in form by simply printing out the PDF, but instead of actually printing it, save it as a PDF. Therefore you can always pull it up again and print off another copy.