When William "Billy" Kerr and his wife, Kerri, bought their 80-year-old bungalow on Anneslie Road near Towson this spring, property taxes were not a major concern.

"When you're sitting there at the closing table, you don't question details," Billy Kerr said. Compared with the $356,500 price of their home - nearly double its last sale price in 1998 - the local taxes seemed "a relatively small amount."

But that was before the Kerrs learned they owed Baltimore County $3,038.94 in taxes, while their next-door neighbors, Daniel and Mary "Grace" Bigelow, had a tax bill for $1,968.27 on a nearly identical house. The Bigelows bought their house six years ago for $115,000.

All over Maryland, buyers of new homes are in the same boat, thanks to sharply higher home prices and a state tax law that gives existing homeowners a break.

The assessment caps that keep taxes low come off when a home changes hands. That means that in parts of Baltimore City and Anne Arundel, Howard and Baltimore counties - as in other real estate hot spots - homeowners in the same neighborhood may get sharply different tax bills on nearly identical homes, depending on when they bought. The current system locks that gap in place until the homes with the lower assessments are sold.

Maryland attorneys general have issued opinions for decades arguing that the system is unconstitutional because it fails to treat all homeowners equally. No one has ever tested that theory with a lawsuit, however.

In California, a tax revolt in 1978 sharply limited property tax increases for existing homes - creating tax gaps in that state as well. In other states with soaring property values, assessment caps, tax rebates, breaks for seniors and other strategies also can create disparities in tax bills.

"Everyone's got a different scenario, and each scenario can be unique," said Bert Waisanen, a tax policy expert at the National Conference of State Legislatures in Denver.

Manageable taxes

Homeowners in Maryland - and their elected representatives - are protected from sudden jumps in their local property tax bills by a multi-tiered system that continually phases in higher home assessments over three-year spans. More important, that system limits annual increases through assessment caps.

When the law first passed the General Assembly in 1977, it included an assessment cap limiting increases to a maximum of 15 percent a year. After a property tax revolt toppled incumbents all over the state in 1990, the General Assembly lowered the cap to 10 percent, and gave local governments the power to go even lower.

Ten of Maryland's 24 jurisdictions have done that. Baltimore City and Baltimore County both have 4 percent caps; Howard County has a 5 percent cap, and Anne Arundel caps increases at 2 percent. Talbot County essentially froze increases with a zero cap.

But when a home changes hands, the cap comes off temporarily, allowing taxes to rise to a level closer to the home's retail value.

Robert Young, associate director of the state Department of Assessments and Taxation, said a tax cap is intended to protect longtime homeowners, not new homebuyers. The assumption, Young said, is that "somebody who is buying the home has the income" to pay the taxes.

Some buyers and even some tax-reform advocates are outraged by the difference in tax bills.

Issue of fairness

"It's definitely not fair," said David Boyd, co-founder of Property Taxpayers United, a Baltimore County tax-protest group formed after sharply higher assessments in 1989. "We're willing to pay our share, but this is not right, and it's got to be corrected."

But James Oglethorpe, a leader of the Howard County Taxpayers Association, takes the opposite view.

"I think it's fair because people move into a home and they understand that's the rule. They're part of the increased demand for all the services," he said. "If they're not aware, they should be."