Reader Jim, who says he bought his house in 1993, asks:

My new assessment for my home is 22% less than it was last year. So won't my next Howard County tax bill (as of the new 7/01/2010 lower assessment) be substantially less than it was for 2009?

The answer is no, it might not be. It's true that assessed values of Maryland homes are plunging, as Larry Carson reported this week. But for many Marylanders who have owned and lived in their homes for many years, property taxes are still "catching up" to the increase in values over the last decade, which is substantial despite the recent meltdown. That's because in Howard County and elsewhere counties often don't allow property taxes to rise as fast as home values.

Let's assume Jim's house was worth $300,000 in his 2001 assessment and is a typical Howard County house. In 2007, after two triennial assessments, it would have been assessed at $625,000. In six years that's a 13 percent average annual increase!

But Jim's real estate taxes didn't go up nearly that much because, under the homestead credit, Howard County limits annual, owner-occupied home tax increases to 5 percent. So say Jim was paying $3,000 in annual tax in 2001. The highest it could have reached in six years under the homestead cap is $4020 -- an increase of only 34 percent, while the value of the home more than doubled. (The Howard County rate actually declined, but not by much. Let's just assume it stayed the same.) So Jim was never paying the fully phased-in tax liability on his house when it was assessed at $625,000. That's why he may not see much if any tax reduction now that his assessed value has plunged 22 percent.

Even with the 22 percent drop, Jim's house would still be worth $487,000. That represents annual value appreciation of 5.5 percent, compounded, since 2001, which is still more than the increase he's seen in property tax. So he and other Howard Countians like me who just got reassessed may even see a slight tax increase this year, not a decline.