Since becoming president in 2017, Donald Trump has donated his entire annual salary of $400,000. Not accepting a salary was a strict promise that Trump made to the American people during his 2016 campaign for the presidency, one which he has kept. Trump donates his $100,000 check to a different federal agency every quarter.

Most recently, Trump donated his Q4 2019 salary to the U.S. Department of Health and Human Services (HHS) with the intent to fight the novel coronavirus pandemic of COVID-19, particularly important considering the urgent need for vaccine development.

Kayleigh McEnany, White House Press Secretary, tweeted the Q4 2019 announcement back in March: "President @realDonaldTrump made a commitment to donate his salary while in office. Honoring that promise and to further protect the American people, he is donating his 2019 Q4 salary to @HHSGov to support the efforts being undertaken to confront, contain, and combat #Coronavirus."

According to a recent tweet by Judd Deere, Special Assistant to the president, Trump will also donate his Q1 2020 check of $100,000 to the HHS.

While most presidents have not donated their paychecks, Trump isn't the first president to refuse a salary.

Herbert Hoover, a millionaire before becoming president, donated his entire presidential salary to a few different charities as well as to his staff.

John F. Kennedy, a millionaire after inheriting a sizable trust fund, donated his entire presidential salary to charities, although he maintained the $50,000 allowance given to presidents as a general expense account (such as for food and dry cleaning). In addition to donating his entire presidential salary, Kennedy donated his entire salary while in Congress, first as a representative and then as a senator. He did that for all 14 years he was in Congress.

George Washington desired to decline his presidential salary, but Congress didn't allow him to do so over special concerns of bribery and the need for financial independence.

U.S. presidents are also paid a pension for life, a lower amount than their salary while in office, according to the Former Presidents Act of 1958. It is unknown if Trump will accept his pension, though that prospect seems unlikely given his wealth and track record in this area.

Trump donated his Q3 2019 check to help fight the opioid crisis.