District of Columbia · D.C. Code §47-850DC homestead deduction after buying: what to file and when it counts

The District deducts $67,500 – increased each year since October 1, 2012 by the cost-of-living adjustment – from the assessed value of real property that qualifies as a homestead, split equally between the tax year's two installments and never carried forward or back (D.C. Code §47-850(a)). It isn't automatic: the owner files an application on the Mayor's form, certified under penalty of perjury, and the Mayor may ask for taxpayer identification numbers of owners and household members, then and later (§47-850(b)). Timing decides how much the buyer gets: an approved application filed between October 1 and March 31 gets the deduction for the entire tax year; one filed between April 1 and September 30 gets half the deduction, for the second installment only (§47-850(c)). Only one lot per homestead and one homestead per household qualify, and the tax bill shows whether the deduction is applied (§47-850(d)–(e)). A separate $445,000 deduction applies to qualifying veterans with a total and permanent service-connected disability, through the Office of Veterans Affairs (§47-850(a-2)).