Q: Can I publish my late father's poem in his name if I do not get paid for the publication?

A: Your late father's copyright will endure for 70 years after his death, assuming he did not create the work for some other entity.

Did your late father hold any interest in his work at the time of his death? That is, did he sell the rights in his work before his death?

If he did not sell or transfer any interest in his literary works before his death, how did he dispose of those interests at his death? If he registered his works with the U.S. Copyright Office, you could look up the copyright claimant information on their website. You may want to update the ownership information if you have an ownership interest in his literary works.

Whether you hold any interest in your late father's work will depend on how his property was distributed at his death. If his property passed via will, and the will had a clause disposing of intellectual property assets, the person named as the beneficiary of the intellectual property assets holds the rights to publish his works. If he died without a will, you'll have to consult the law of the state in which his assets were disposed, likely where he lived and held property at the time of his death.

All that being said, who else might own an interest in your late father's literary works? Your siblings? You may be a co-owner of his works, or you may have no interest at all in his works. Whether republishing his work online will pose a problem for you depends on whether the current copyright holder of the work will seek compensation for your unauthorized use of the work (without knowing how your father's property was distributed, no one will be able to tell you whether your use is authorized). A simple solution may be to ask all potential owners for permission to post your father's poem online. If every possible copyright claimant consents to this use in writing, who would sue you?

You don't have to receive compensation to be liable for copyright infringement.