There is a maximum percent the tax assessment can go up each year in MoCo. If the owner has been there a long time, then the tax would be artificially low. It gets "reset" when it chantes hands.

Don't assume you'll inherit the tax assessment. If you buy it, it will most likely reset to at or near your purchase price.

Could also have been an exoansion and not an in cycle reassessment.

(OP here) Hmm. You might be right. It needs a lot of updating and renovation, so that's not it, but I think the seller's owned it since forever so that could be it.

Tax assessors dont go into homes when they make their assessments. Could be that the house is super upgraded inside. also, many times the assessment on a home is sometimes very low when the house hasnt changed hands in a while.

I know that valuation for tax purposes doesn't move in lock step with prevailing sales prices, but what would you make of a large (about $250k) difference between them? It's a neighborhood with little turnover so there aren't any comps and it's been on the market for a while, so I'm wondering just how out to lunch the seller is or whether I'm not thinking of something.