Tax Credit Basis Boost Calculator

DDA/QCT basis boost multiplies eligible basis by 1.3 for LIHTC.

Eligible basis

Basis boost (1.3)

Applicable fraction %

Credit rate %

10-year credit uplift

$8,100,000

10-year credit w/ boost

$35,100,000

10-year credit w/o boost

$27,000,000

How the math works

Credit = eligible basis × boost × applicable fraction × rate × 10 years.

$30M × 1.3 × 100% × 9% × 10 = $35.1M with boost. $27M without = $8.1M uplift from DDA/QCT boost.

How to Use

Enter eligible basis.
Enter DDA/QCT boost (1.3 = 30% boost).
Enter applicable fraction %.
Enter credit rate %.
Read credit uplift from boost.

Frequently Asked Questions

What is basis boost?

DDA (Difficult Development Area) and QCT (Qualified Census Tract) designation provides 30% boost to LIHTC eligible basis. Effectively = eligible basis × 1.3 × applicable fraction. Substantially increases generated LIHTC credit. States can designate additional 30% boost areas in state QAP (Qualified Allocation Plan). Basis boost can be stacked with 100% low-income applicable fraction for maximum credit generation.

How do I check DDA/QCT status?

HUD publishes DDA and QCT maps annually (updated). Check address against interactive maps at huduser.gov. DDAs designated based on high land cost relative to AMI. QCTs based on poverty rate (>25%) or median income (<60% of area median). State boost areas in state QAP. Developers should check at project conception — deal feasibility often turns on presence.

Financial impact?

Without boost: $30M eligible basis × 100% × 9% × 10 years = $27M credits. With 30% boost: $30M × 1.3 × 100% × 9% × 10 years = $35.1M credits. $8.1M additional credit = $6.5M+ additional equity at typical syndication yield. Major value driver. Projects outside boost areas often don't pencil; projects inside often highly profitable.

Boost interaction with 4% credit?

Same 30% boost applies to 4% credit (tax-exempt bond deals). Combined with tax-exempt bond financing, boosted basis provides: (1) substantial LIHTC equity, (2) below-market debt, (3) property tax abatement (often), (4) other subsidies. Can make pure 60% AMI affordable deal pencil. Experienced affordable developer can find deals that work with these stacked benefits.