D.C. Code § 2-1215.21

The District government, the federal government, or any property owner owning exempt real property located in the BID, or adjacent to or abutting BID boundaries, may, at their sole discretion, contribute money to the BID. Such exempt real property owners who voluntarily make a payment to the BID in lieu of a BID tax shall be entitled to membership in the BID and services provided to the properties in the BID. Nothing in this subchapter shall either compel or prohibit such exempt real property owners from contributing BID taxes, becoming BID members, or receiving BID services.