The tanking housing market has created the largest drop in property assessments in county history, but homeowners should not expect a similar decline in their tax bills.

Home values assessed in Anne Arundel County this year dropped by 19.7 percent since they were last appraised three years ago, according to new tax assessment notices mailed to homeowners yesterday.

The decline mirrors statewide trends, but officials cautioned that Anne Arundel's tax structure makes it unlikely that most residential tax bills will change much, if at all.

Homestead exemptions and the county's property tax revenue cap have buffered...