WASHINGTON — Like the service men and women they are, the participants in my yearlong money-management challenge have hunkered down and are attacking their debts with mighty force.

In less than four months, Kim and George Colon have drastically cut their household expenses and have managed to pay off more than $8,800 in consumer and tax debt. Kim, 43, is a senior master sergeant in the Air Force. She’s been in the military for almost 20 years. George is 52 and retired from the Army after serving 22 years.

Tarek and Evibeth Bathiche, both 24-year-old Army personnel stationed at Fort Meade, Md., have paid off more than $16,000 in consumer debt since being put on my debt diet by cutting expenses and using a re-enlistment bonus Tarek received. Evibeth is a sergeant and Tarek just got promoted to staff sergeant.

Amber and Trenton Holmes have paid off more than $1,200 owed in credit card and retail debt. Trenton is an aircraft mechanic and tech sergeant with the Air Force. Amber is a paralegal specialist with the federal government.

In this year’s challenge, I wanted to work with military personnel. Throughout the year these three families in the Color of Money Military Challenge will open up their financial lives and follow debt-reduction plans I’ve laid out for them.

Several reports by the Defense Department and the Government Accountability Office have found that many military personnel are in financial trouble and that in turn may be affecting our country’s military readiness.

Family separations resulting from duty-station changes and deployments often put additional financial stress on military personnel, says Janet Pearson, publisher of Military-Money-Matters.com.

Serious financial problems can have a negative impact on service members’ careers. They could lead to loss of security clearance and other adverse personnel actions, including discharge.

Unchecked spending and the overuse of credit are what has landed the three military families in trouble.

The first step in their plan was to give up their credit cards.

Cutting off their credit supply forced the families to budget better.

“Not a lot of people can say that they are a cash-only family,” Tarek Bathiche said, adding: “At the same time it has been hard to discipline ourselves and our spending habits.”

George and Kim Colon have found that paying off the debts with the lowest balance first has motivated them to stick to their payoff plan.

Their original strategy of paying off the highest-interest debt first does make sense mathematically. But people in debt often get discouraged and abandon their payoff plan when the list of debts remains the same for too long.

“We didn’t see progress,” Kim said. “Now we’re just knocking them off.”

By attacking the lowest balance debt first, the Colons and the other couples were able to cross off entire bills in just a matter of months. That in turn motivated them to cut back their expenses even more and find more cash to throw at their debts.

It’s that same dark feeling of overwhelming debt that has forced Amber and Trenton Holmes to stick to their plan.

Unfortunately, they have had to tackle some needed and expensive home repairs, which have slowed them down a bit. However, the biggest impediment to their plan is their mortgage on a second home.

Like many people in recent years, the Holmeses decided to trade up to a bigger home. They thought they would have no problem either renting or selling their first home. They were wrong.

The housing market tanked and they’re now stuck paying about $1,000 a month on the second property. They have renters but the rent doesn’t cover the entire $2,800 monthly mortgage payment.

“I’m still frustrated because for me this is out of my comfort zone,” said Trenton, who isn’t used to being so cash-strapped. A lifelong saver, he’s struggling with the notion of being buried under so much debt.

Overall, I’m pleased with all the challengers’ results so far. These military families are displaying the kind of discipline any drill sergeant would expect and require.

Michelle Singletary is a personal finance columnist for The Washington Post, 1150 15th St., N.W., Washington, D.C. 20071 and may be e-mailed at singletary@washpost.com