You've got a dead oak leaning toward your house. Or a storm dropped a limb through your fence. Or you're clearing land for a renovation. Tree removal in this area is complicated by overhead power lines, narrow lots, and local tree ordinances that require permits for trees over a certain diameter.
A certified arborist (look for the ISA credential) knows how to assess whether a tree is actually dead or just stressed, which matters because dead trees come down differently. They also know how to section and drop a tree in a tight urban lot without taking out your neighbor's fence. General landscapers with chainsaws are not the same thing.
Tree removal typically runs $300-$2,000+ depending on size and access. Always get proof of liability insurance - if a crew member or a limb damages something without it, that's your problem. Stump grinding is usually separate, around $100-$300. Some Bethesda and Chevy Chase permits require replacement planting, so ask before you remove anything significant.