FOX 5 was first to report on the error discovered by Louis Wilen, a retired computer programmer from Olney.
It took years for Wilen to convince state officials that Maryland has long been miscalculating the Homeowners Tax Credit (HTC) for some residents primarily in Montgomery County and Baltimore city.
"They tried to ignore me," Wilen said.
HTC is a credit for low-income residents and seniors who own homes. After the mistake was exposed, the state issued refunds totaling $8 million in 2021.
Now another round of checks has arrived in Montgomery County mailboxes. Wilen has maintained the county also owes people money because of the state miscalculation.
"We owe it back to people, there's not a question about that," said Montgomery County Executive Marc Elrich.
The county says it's issued checks to 5,455 homeowners, specifically those eligible for the county's $346 yearly senior supplement. The county refunded up to three years of supplement, so some checks were for over $1,000.
"I'm really glad that Louis Wilen, who can be very persistent, did a good job of figuring this out and I thank him and I think the people getting the check should thank him because his work made this possible," Elrich said.
The county initially thought the checks would come by the end of 2021 or early 2022, but Elrich said it took the state months to get the county the information needed to issue refunds. The initial estimate was that the refunds would total $8 million. County officials said they are confident refunds have been paid to everyone who's owed.
Wilen's efforts are a reminder to ask questions and do the math. Between state and county refunds, exposing the state error led to $12 million going back to homeowners and because the state fixed the mistake and stopped shortchanging people, taxpayers will keep countless millions into the future.