Yes, he can be. However, it is not clear that he has to reply to it. He can refuse most subpoena because of his right of executive privilege.
Theodore Roosevelt
Andrew Johnson
Woodrow Wilson (1919)
Susan faced a dilemma when she was subpoenaed by the courts
James A. Garfield
He was the sitting Governor of the state of Texas.
In March of 1807, President Jefferson issued a written statement roundly condemning the institution of slavery in the US. He was the first sitting president to do so before President Abraham Lincoln's time.
No US president- elect has been assassinated. Four sitting presidents have been assassinated: Lincoln.Garfield,McKinley and Kennedy.
a president that is in ofice
There are one hundred senators, two from each state in the union. If you include the President of the Senate, who is not an elected senator but who is the sitting vice president of the US, you could say there are 101 seats. The President of the Senate can break a tie vote.
This is the location that President Abraham Lincoln, the 16th president of the US, was assassinated in 1865. He was sitting in the balcony when John Wilkes Booth shot him from behind in the head.
Sitting means "current" or "active" president. According to the smarties on StackExchange politics, it is acceptable, to call ex-presidents "Mister [lastname]", or "Former President", or even "Mister President" - even though they no longer have that role. Famously, Marilyn Monroe addressed a sitting member of the executive staff (President Kennedy) as "Mister President" in a happy birthday song, and most guys who listened to that.. well, their members were standing rather than sitting afterwards. ;)