Health and Human Services Secretary Tom Price may have violated a federal policy that requires officials to use the cheapest travel options available by repeatedly taking chartered flights, the Washington Post reports . HHS’s inspector general is investigating the matter.

Update September 29, 4:40 p.m. EST: President Trump has accepted Price’s resignation. Don J. White, a deputy assistant secretary at the agency, will be his temporary replacement.

It’s just the latest criticism leveled against executive branch officials over costly travel, under an administration in which, as Newsweek reported, President Trump is likely to outpace Barack Obama’s eight-year travel spend in just his first year in office.

Two other high-ranking Trump administration officials are also under investigation for their taxpayer-funded travel: Agency inspectors general are also scrutinizing Environmental Protection Agency head Scott Pruitt’s frequent trips to his home state of Oklahoma and Treasury Secretary Steve Mnuchin’s trip to Kentucky.

Here are some of the numbers that have surfaced around Price’s trips:

24 flights since May: How many times Price has flown private, at least. A Price spokesperson has said the charter jets are necessary for him to efficiently travel, manage a “$1.2 trillion agency,” and connect with constituents without dealing with airport delays and other hassles of commercial flight. (A critic of big government spending, Price tweeted in 2009, “Congress doesn’t need to have private jets.”)

How many times Price has flown private, at least. A Price spokesperson has said the charter jets are necessary for him to efficiently travel, manage a “$1.2 trillion agency,” and connect with constituents without dealing with airport delays and other hassles of commercial flight. (A critic of big government spending, Price tweeted in 2009, “Congress doesn’t need to have private jets.”) $300,000: The minimum total cost of his flights, according to the Post report.

The minimum total cost of his flights, according to the Post report. $25,000: The cost of one flight for Price and about 10 other people from Washington, D.C.’S Dulles International Airport to Philadelphia, Politico reports. By comparison, commercial flights likely would have cost between $447 to $725 per person—less with government discounts and early booking—and the group likely could have saved even more by driving or taking the train.

The cost of one flight for Price and about 10 other people from Washington, D.C.’S Dulles International Airport to Philadelphia, Politico reports. By comparison, commercial flights likely would have cost between $447 to $725 per person—less with government discounts and early booking—and the group likely could have saved even more by driving or taking the train. Five: number of Democratic ranking members of congressional committees who signed a letter on Thursday requesting a review of Price’s trips.

Other administration officials and family members are facing scrutiny for high-altitude taxpayer-funded figures like these:

$1,980: The cost of one of EPA head Scott Pruitt’s tickets on a commercial flight to Oklahoma, far in excess of what an economy ticket typically costs on that route. From March to May, Pruitt was in Oklahoma 43 days, according to records obtained by the Environmental Integrity Project watchdog group.

The cost of one of EPA head Scott Pruitt’s tickets on a commercial flight to Oklahoma, far in excess of what an economy ticket typically costs on that route. From March to May, Pruitt was in Oklahoma 43 days, according to records obtained by the Environmental Integrity Project watchdog group. $25,000: The cost per hour to operate the U.S. Air Force jet that took Treasury Secretary Steve Mnuchin from New York to Washington, D.C. on Aug. 15, when he and other cabinet members were in New York for a now-infamous press conference at Trump Tower following the violence in Charlottesville. Transportation Secretary Elaine Chao also flew on the C-37 jet, which is the government’s version of a Gulfstream V.

The cost per hour to operate the U.S. Air Force jet that took Treasury Secretary Steve Mnuchin from New York to Washington, D.C. on Aug. 15, when he and other cabinet members were in New York for a now-infamous press conference at Trump Tower following the violence in Charlottesville. Transportation Secretary Elaine Chao also flew on the C-37 jet, which is the government’s version of a Gulfstream V. $25,000: The cost per hour to operate the government jet that was proposed by Mnuchin’s office to take him and his wife, actress Louise Linton, on their European honeymoon in early August. (The request was subsequently withdrawn.) In August the couple flew to Kentucky on a government jet, in a widely discussed visit to Fort Knox. While the trip coincided with the totality of the solar eclipse that day, Mnuchin insists it was a coincidence.

The cost per hour to operate the government jet that was proposed by Mnuchin’s office to take him and his wife, actress Louise Linton, on their European honeymoon in early August. (The request was subsequently withdrawn.) In August the couple flew to Kentucky on a government jet, in a widely discussed visit to Fort Knox. While the trip coincided with the totality of the solar eclipse that day, Mnuchin insists it was a coincidence. Four: The number of luxury brands that Linton tagged in an Instagram glamour shot that showed her deplaning in Kentucky. Linton then took to the comments to call a critic who was upset by her lavish publicly funded travel “adorably out of touch,” and made her account private. The trip is now the focus of a Freedom of Information Act lawsuit by a government watchdog group.

The number of luxury brands that Linton tagged in an Instagram glamour shot that showed her deplaning in Kentucky. Linton then took to the comments to call a critic who was upset by her lavish publicly funded travel “adorably out of touch,” and made her account private. The trip is now the focus of a Freedom of Information Act lawsuit by a government watchdog group. $66,000: The estimated costs incurred during a high-end ski resort visit by Ivanka Trump, Jared Kushner, and their children in April, to cover the hotels, ski passes, and “recreational equipment” for the Secret Service, NBC News reported.

The estimated costs incurred during a high-end ski resort visit by Ivanka Trump, Jared Kushner, and their children in April, to cover the hotels, ski passes, and “recreational equipment” for the Secret Service, NBC News reported. $19,289 : The cost of two hotel bills related to Tiffany Trump’s trip to Berlin with her boyfriend in early June, according to USASpending.gov, which catalogs all federal government spending.

: The cost of two hotel bills related to Tiffany Trump’s trip to Berlin with her boyfriend in early June, according to USASpending.gov, which catalogs all federal government spending. $97,830: The cost to taxpayers from Eric Trump’s January business trip to Urugray, according to the Post. Donald Trump Jr., who also travels the world to oversee the family business empire while under Secret Service protection, has also run up big tabs for taxpayers. Frequent trips to Mar-a-Lago, New York, and other Trump resorts have reportedly cost the government millions and, according to USA Today, led more than 1,000 agents to already hit the salary and overtime allowance meant to last the entire year. (Trump, Jr. and White House advisor Kellyanne Conway recently elected to decline further Secret Service protection.)

The Trump administration has had at least one big win for budget-conscious executive travel: As the President demanded, as part of his efforts to drain the swamp, the U.S. Air Force in August secured a bargain price on two 4-year-old Boeing 747-8s for the Air Force One fleet. (The optics there could be a little better, though: It turns out the pair of planes have a Russia connection.)