In May 2025, Donald Trump Jr. questioned on X how "Dr. Jill Biden" missed former President Joe Biden's aggressive metastatic cancer. Former U.S. first lady Jill Biden holds a doctorate in education. She is not a medical doctor. Donald Trump Jr. later wrote on X that he meant his comment to be sarcastic.

Biden's health, both physical and mental, was discussed at length during the 2024 presidential election cycle, more recently after excerpts from a new book by CNN 's Jake Tapper and Axios' Alex Thompson, Original Sin: President Biden's Decline, Its Cover-Up, and His Disastrous Choice to Run Again, were published by multiple media outlets.

President Donald Trump said Monday he was “surprised” the public didn’t know about former President Joe Biden’s cancer diagnosis sooner—a comment that came after other Republicans, including Vice President JD Vance, appeared to insinuate Biden may have hidden his cancer diagnosis from the American public while he was in office.

The book said that the Biden family wanted to keep Beau Biden’s cancer diagnosis a secret and misled the media about his condition.

The president's son suggested there was a cover-up after former president Joe Biden announced his prostate cancer diagnosis.