In the US, an author holds the copyright to his work for all his life, and his heirs hold it for 70 years after his death, at which point the work becomes public domain. (source) In other countries the number of years after the author's death may vary, but I do not know of a single country nowadays where copyright expired before author's death. (This used to be the case in the beginning of last century - copyright would only last for X years after publication. It isn't the case now.)
A publisher pays the author royalties in exchange for the rights to publish their work. Since the author holds the copyright, the publisher cannot just go ahead and publish - the right needs to be paid for. That's what royalties are. (Source)
So to answer your question, yes, a living author continues to get paid royalties for their older works.