Is this address in a QCT or a DDA?

What the two designations mean

A Qualified Census Tract is a tract where at least half of households earn under 60% of area median gross income, or where the poverty rate is 25% or higher. HUD can't designate more than 20% of any one metro or nonmetro area's population as QCTs, so a tract can meet the income test and still miss the list.

A Difficult Development Area is a place where construction, land and utility costs run high relative to income. In metro areas HUD draws DDAs by ZCTA, which is why they're called Small DDAs. Outside metro areas the DDA is the whole county. Each group is capped at 20% of the aggregate metro or nonmetro population.

The payoff is the same for both. Section 42(d)(5)(B) lets eligible basis rise to as much as 130% of what it would otherwise be, so the credit rises by up to 30%. On a 9% deal that turns a 70% present-value credit into as much as 91%.

A worked example

Take a 60-unit new construction deal with $15,000,000 of eligible basis, every unit set aside, and a 9% applicable percentage.

The extra $4,050,000 of credits counts only if the agency awards it (IRC 42(m)(2) limits credits to what the deal needs). On a 9% deal the agency sizes the award to the gap it finds, so the boost raises what you can ask for rather than what you'll get. On a 4% bond deal the credit isn't competitive, which is why the boost often decides whether a bond deal pencils. Run your own numbers.

Which year's list counts

HUD publishes new lists each fall. The 2027 lists, published in the Federal Register on October 6, 2026, take effect for credit allocations after December 31, 2026, and for bond deals where the bonds are issued and the building is placed in service after that date. If a site drops off a later list, it keeps the old status when a complete application was filed before the new list took effect and credits are allocated within 730 days of that filing (for bond deals, the bonds are issued or the building placed in service within the 730 days). For multiphase projects, the status when the first phase got its allocation carries to every phase, if the phases were disclosed up front and applied for in consecutive years (HUD notice, FR Doc. 2026-20390, section VII).

Two limits on this tool. The geocoder can place an address near a tract line on the wrong side, and a metro ZCTA's boundary rarely matches the post office ZIP exactly. Before you rely on a result in an application, confirm it on HUD's QCT and DDA map and with your allocating agency.