
A cut stump at or above grade with the original root system intact below it. Over time: mushrooms or shelf fungi on the top and sides, bark separating from the wood, the surface going soft and punky, ants or beetles working the interior, and a sunken ring in the lawn as the roots break down. Plus a trip hazard and a mower you keep steering around. A stump is a slowly decaying mass of wood, not a hazard. It is not going to fall and it poses no structural threat to a house. What it actually does is occupy the spot you probably want to replant, keep feeding decay fungi already present in the soil, and interfere with mowing. The one forward-looking concern is that some stump-colonizing root-decay fungi, Armillaria among them, can also attack living roots of nearby trees — so a stump acts as a reservoir rather than an inert object.
Not urgent. Normally a stump grinding job, $100–$700 around Indianapolis depending on size and access.
Nothing to save; the question is how it leaves. Grinding is the standard — a machine chews the stump and major surface roots to a depth commonly around six to twelve inches below grade, deeper if you intend to plant in the same spot. Full extraction with an excavator takes the root mass but tears up far more yard and costs more. Chemical stump removers and the Epsom-salt method speed decay only marginally and take years. One planning point people miss: grinding produces more chip volume than the hole it leaves, and those chips tie up nitrogen, so replanting in the exact spot means excavating the grindings and backfilling with soil, or simply planting a few feet to the side.