Congress is facing more challenges than it has ever before — ethical, political, financial … and numismatic.

Challenge coins have spilled out across the Capitol’s hallways like change from a broken piggy bank. Having long embraced the military, members of Congress are now embracing one of its traditions: minting custom coins that celebrate a particular unit, squadron, ship or office.

At least 10 members — all veterans by Roll Call’s count — hand out their own, personalized coins, decorated with details about their lives and districts. They’re usually around 2 inches in diameter and twice as thick as a silver dollar, but vary in size, shape and heft.

Rep. Tony Gonzales’ coin is more rectangular, featuring the retired Navy master chief petty officer’s two stars and anchor insignia, a destroyer, a P-3 Orion surveillance plane, his cryptologic technician emblem, 29 stars (one for each county he represents) and the congressional seal. All those elements give the Texas Republican’s coin enough heft to use as a weapon. “That way, in case there’s an insurrection, you’re ready to go,” he joked.

The coins get their “challenge” in the form of a check: A coin holder — usually a member of a specific military unit, police department or firehouse, and usually out drinking with some of his comrades — shouts “coin check,” requiring the rest of the group to produce their tokens. If someone doesn’t have their coin on them, then they’ll have to pay for a round of drinks. But if everyone’s rolling in coins, then the well-met challenger ponies up for the next round.

As with most traditions, especially those involving alcohol, there are variants to the rule — loser has to chug a beer, or do pushups, or do pushups while chugging a beer — but the underlying ethos of instilling an esprit de corps doesn’t change.

Arkansas Rep. Steve Womack, for example, likes handing out his congressional coins to children, “to inspire them to do good, to have goals and objectives and to honor their country.”

California Rep. Mike Garcia got his first challenge coin as a kid, when the captain of the USS Ranger passed them out on a tour of the aircraft carrier. The former naval aviator’s congressional coin crams in a ton of references to his SoCal district: an F-35 joint strike fighter jet (built partially in the district), Ronald Reagan (the presidential library is there), some rides from the 25th’s Magic Mountain amusement park, a rock formation made famous as the backdrop for some early “Star Trek” episodes, and poppies. Despite all that, there’s still room for a built-in bottle opener.

Garcia admits that last feature could have come in handy back in his Navy days. “I’ve been burned a couple of times,” forgetting his squadron coin at the bar, he said. “It’s a camaraderie thing — it’s meant to be like a uniform, something that binds the team.”

Tennessee Republican Rep. Mark Green’s “coolest” coin check in the Army happened in the back of a helicopter in Afghanistan after picking up some special operations soldiers. “A buddy of mine got in the aircraft,” he said. “He saw me and coin checked me. Of course, I’m in my kit with all my gear, I didn’t have it on me. So, I had to buy him a beer.”

It’s not clear how exactly the military tradition began, but one legend dates it back to World War I: When a nameless American soldier — or maybe a pilot — was mistakenly captured by the French, he used his unit’s commemorative coin to prove he wasn’t German. Another tale traces it all the way back to the Revolution — apparently General George Washington would hand out gold coins to his aides, and that led to commanders giving the officers beneath them specially-minted coins to prove they were American soldiers, not spies. Perhaps more accurate accounts say the tradition began in Korea or Vietnam, beginning with elite special forces units or fighter pilot squadrons.

No one CQ Roll Call spoke to for this story — we emailed 90 congressional offices, asking every veteran in the House and Senate — expressed any qualms about civilians co-opting this military tradition in recent decades. Green, a Bronze Star recipient who served with the 82nd Airborne and as the flight surgeon for the 160th Special Operations Aviation Regiment, said he’s happy to see it spread.

“Our country is made better by many military traditions going out into the country,” he said. “I love the idea that there is a coin out there for law enforcement, for firefighters, sheriffs, schools, nonprofits — I think it’s great.”

According to Jordan Haines, CEO of challenge coin manufacturer CoinForce, only a few units issued coins when he was enlisted. He got his first in 1988, while working as a mechanic on fighter jets in South Korea, a full eight years after he joined the Air Force. Later, when he became a flight engineer, he got his second upon joining his squadron in 1992, along with the unit’s other swag — T-shirts, hats. It was only then that he was introduced to a coin check.

Since Haines started his company in 2003, he’s minted more than 3 million coins.  Haines estimates that at the start, military units and affiliates like VFW halls made up 90 percent of his orders. Now they’re about half, with the rest coming from the civilian world, including politicians.

Civilian coins really boomed around 2005, Haines said, as troops who served in Iraq and Afghanistan brought the tradition with them as they recirculated back into civilian life. They first took off among police and fire departments, which recruit heavily from ex-military ranks and share similar cultures, but coins have expanded far beyond that since.

The tradition is to give someone a coin as part of a handshake — to slip it into your slightly upward-facing palm, then rotate your hand so the recipient holds it after the shake. Some coins are earned — Gonzales says he’s handed out only five of his so far — while others are handed out freely. Military units often give challenge coins to visiting dignitaries, and many lawmakers like to reciprocate with their own.

“Even though we no longer wear the uniform, we can continue to be an example of a nation in service to others,” Pennsylvania Rep. Chrissy Houlahan said in a statement. “It’s why I brought the challenge coin tradition to my office — to thank the many veterans and service members I meet for being part of that common cause.” 

Like medals and ribbons, they can tell a story: Displayed at home or in the office, challenge coins can tell you where someone’s been, who they’ve met.

“I have about 2,000 coins in my [home] office — my granddaughters call it my treasure chest,” said Rep. Don Bacon of Nebraska. “I’ve got coins from presidents, joint chiefs of staff, joint chief chairmen and vice chairmen.”

Over the course of his nearly 30 years in the Air Force, Bacon minted five command coins of his own, but decided against crafting one for his congressional office. “It costs a little bit of money to design and print them and I’m in an R+1 district, so it didn’t feel like the right focus.”

Coins aren’t cheap. Most will run around $6-$7 per coin, not counting design fees, and really complex or large coins can easily cost double that.

Members minting their own coins cannot use office funds for them, according to guidance from the Senate Ethics Committee. The cash for coins has to come out of either their own pocket or out of campaign funds. Paying with the latter comes with various conditions — like not using the Senate seal if you want to hand them out at campaign events — as the committee detailed in a letter earlier this year.

Senate guidance was even stricter before that. Personalized challenge coins (bearing a lawmaker’s name or likeness) were banned because they carried a risk of “undue self-promotion and conflation of campaign and official activities,” according to a 2016 letter. But the Ethics panel relaxed its stance in July, citing “an ever-growing number of civilian public officials” adopting the tradition. (The House Ethics Committee has not specifically addressed challenge coins, but many members we spoke to said they use personal funds.)     

The trend is bipartisan: Democrats Kai Kahele of Hawaii and Houlahan, both Air Force vets, have their own designs. Kahele likes to give his coin, featuring the C-17s he flew and two volleyballs for the sport he played in college, to members of his staff who go above and beyond the call of duty, “and, of course, my wife,” he said. “She’s very important.”

It’s also bicameral, but out of the 16 veterans in the Senate, only Iowa’s Joni Ernst responded to CQ Roll Call’s coin check. “As a former company commander who served our nation in uniform for over 23 years, I proudly present my Challenge Coins to those who exercise leadership, serve selflessly, and exemplify a determined spirit — from our veterans, servicemembers, and the brave men and women in law enforcement, to people of all ages who join me for ruck marches, one of my favorite traditions while serving in the Senate,” she said in an emailed statement.