Homeowners association (HOA) fees are rising significantly, often acting like a "shadow mortgage" with unpredictable increases and special assessments that can strain budgets and even lead to foreclosure. Median HOA fees have grown, with some areas seeing fees that consume a large portion of housing costs. Unpaid dues can result in liens or foreclosure, sometimes taking priority over mortgages. Buyers should carefully review HOA documents and budget for potential fee hikes.