Assessing Your Pain

"If the fireplace doesn't work anymore or if our worksheet shows two bathrooms instead of one" or if the house has been damaged by flooding or development around it or has other problems, then a challenge would be in order, Sullivan said.

Assessment officials add that eye-popping assessments don't necessarily lead to corresponding tax bill increases. Maryland caps assessment increases statewide at 10 percent a year for tax purposes for people who live in their homes, with some counties keeping increases even lower. (Talbot County assessments are capped at their present level, Anne Arundel has a 2 percent assessment cap, and Prince George's sets it at 3 percent.) The District caps the annual tax-bill increase at 12 percent.

Virginia doesn't have any caps but generally has lower tax rates than jurisdictions across the river.

And local elected officials annually consider raising or lowering the actual tax rate.

Most area governments also offer some tax breaks, sometimes called homestead tax deductions, for owners who live in their properties. And some have tax credits for seniors or low-income families. But critics, such as taxpayer groups, say that's not adequate these days. They say the deductions and credits have not been adjusted in years to reflect higher property values.

Sullivan and county tax assessors in Maryland say they don't see a huge wave of appeals so far, despite the size of the most recent increases. Maryland's assessments are up 46.6 percent on average from three years ago, the largest value increase in the state since the beginning of the three-year assessment cycle in 1980.

"I think people were in shock when they got [the notices], but people also understand that the market has gone up considerably," said Joseph V. Glorioso, supervisor of assessments in Anne Arundel County.

And those officials also don't expect an appeals avalanche by the deadline date of Feb. 14 because Maryland has beefed up its computer systems for detecting neighborhoods where values are out of whack and alerting county assessors to possible problem areas before notices go out.

"Before we finalize the figures, the state has a check system, a computer program, for abnormal increases or decreases. It tells you the neighborhoods where these numbers are up or down abnormally, so we go back in and look at those neighborhoods" before sending the notices, said James P. Soresi, supervisor of assessments in Prince George's County.

Only 3 to 4 percent of Maryland residents have appealed their assessments in recent years; fewer than 1 percent have done so in Fairfax County, the most populous county in Virginia. The rate has been higher in recent years in the District -- at about 7 percent -- but District officials aren't offering estimates for this year's round of assessments, which aren't scheduled to arrive until next month.

Only Arlington County has mailed its notices so far in Virginia. Alexandria sends them on Tuesday, and others in the state will follow soon after.

In most jurisdictions in the past, about a third to a half of the people filing appeals have won reductions, say assessment officials.

If you want to challenge your assessment, first take a good look at the notice. It will tell you the steps to take. They vary by locality.

You can also consult the local government's Web site. Most have online appeals forms that can be printed out and submitted. Some, such as Fairfax County, disclose online the details about your house that the assessors considered, giving you a rundown of where to look for errors.