I also live in MD. I received my assessment last year, appealed it and had the assessment reduced. I'm in a 37 year old rancher, with good schools, and my neighborhood is not in decline. You should file an appeal. The instructions for doing so are included with you assessment notice. I found it to be a very informal and non-intimidating process. I never even brought up the real estate market. I basically explained why I felt my house wasn't worth what it was assessed at. I even had pictures of all the things that are wrong with my house, and I wasn't even asked to show them. I don't see what the Homestead Tax Credit has to do with anything. They say your house is worth a certain amount and you don't agree, period. Sounds to me like they might be trying to discourage people from appealing to avoid the extra work. You don't have to pay anybody for information. Whatever you need is publicly available to you for free, and a lot of useful information is on the internet. Here is a link that might be useful: MD Real Property Data Search

Let's clarify Zillow's statistical use: they can't make something out of nothing. If there has not been sufficient sales activity in your area to do comps, they cannot use only your house, no matter how long or short a time you have been in it, as the sole "average price". What you paid for your house will be averaged out with a pre-determined circular geographic area of roughly similar houses. If there aren't enough houses nearby, or not enough SIMILAR houses have been sold recently, the comps are going to be off. They don't claim complete accuracy, it is a STARTING point for people who are afraid to call a local RE agent and bother them every single month to find out "what their house is worth right now." And if you want Zillow to be more accurate, how many of you have bothered to update your housing profiles? It takes a little time, and many people don't bother. So why be surprised if it's not accurate? They get their info off the public records. I had to instruct the county tax assessor not once, but twice, in phone conversations during the earlier years we had the tax assessment reduced, on the correct # of rooms and bathrooms we had, even though the county had that information from the remodeling permits we had filed in 1989. But it took the tax assessors 8 years to correct their own records! Zillow corrects itself a lot faster, and over time will get more accurate in most areas -- not all because they just won't have #s to be statistically valid.

I can't seem to make heads or tails of Zillow. The house beside of ours is priced $65,000 less than the exact same house around the corner. Both are located on cul-de-sacs. Both have deeded boatslips. Both are three car full brick homes with the same floorplan. However the one which is priced less has a full basement! Go figure...didn't realize that a walk-out basement could actually devalue a home. The only difference is that the one that is priced higher just sold about 9 months ago and Zillow has its estimated value the same as the sales price. I wonder why it doesn't believe that the other house would sale for a similar price? It seems that in my neighborhood nearly every house is priced about $100,000 less than what they are selling for. Could that be because we are on a lake and Zillow doesn't care about that? The other houses in our zip code are rural and usually sell for $300,000 less than the lake neighborhoods, but of course this brings down the zip code average price.

jpok, your comment here makes it sound as if the govt of CA willingly foregoes taxing houses on the market value: "And, in California the tax assessment is based more on the original sale price with small adjustments - I guess they do this because the tremendous price appreciation would make it difficult for a lot of people to afford the property taxes on the true market value." Not true! No way would tax-hungry CA let us get away with that. In 1978 voters put in place Proposition 13 which limits the taxation on property. Otherwise many people who had purchased homes decades before could have lost their property due to the surge in RE prices (and therefore taxes) that would have overwhelmed them. I'm copying this next part from Wikipedia: "Under Proposition 13, the real estate tax on a parcel of residential property is limited to 1% of its assessed value, until the property is resold. This "assessed value", however, may only be increased by a maximum of 2% per year. If the property's market value increases rapidly (values of many detached dwellings in California have appreciated at annual rates averaging more than 10% over the course of several years) or if inflation exceeds 2% (common), the differential between the owner's taxes and the taxes a new owner would have to pay can become quite large. The property may be reassessed under certain conditions, when additions or new construction occur; the assessed value is also subject to reduction if the value of the house declines, say during a real estate slump." Prop 13 has been very popular with residents but not so much with the CA govt and those who depend on taxes for their salary increases etc. It was a big concern for Gov Schwarzenegger when his financial consultant Warren Buffet said he would work against Prop 13. Arnold quickly put a stop to that kind of talk. And, back to your posting, I also use aerial maps to look at a property's location, the way it fits into the neighborhood, how big the lot is, etc. I find it very useful.