Special Assessment Bond Calculator

Special assessment bonds add to tax burden. This calculator sizes the impact.

Bond amount

Bond rate

Bond term years

Property share %

Remaining years

Annual assessment

$30,015

Remaining total cost

$540,269

Property share $

$450,000

How the math works

Annual district debt service × property share = annual assessment. Remaining cost = assessment × years.

Special assessment bonds often add 1-3% of assessed value to a buyer's annual carry. Run the disclosure documents through underwriting as a separate line — a $25k annual assessment at a 6% cap rate is $400k of implicit value reduction below headline market value.

How to Use

Enter total bond amount (district).
Enter bond rate %.
Enter bond term years.
Enter property share %.
Enter remaining years.
Read annual assessment.

Frequently Asked Questions

What bonds cover?

Road improvements, sewer lines, water system, sidewalks, streetlights. Property owners in benefited district pay proportional share. Amortized over 15-30 years typical. Rate 3-7% typical for AAA munis.

Prepayment?

Some districts allow prepayment: pay off pro rata share at closing. Reduces future tax burden. Prepayment discount often available (5-15% off face). Worth running NPV — sometimes better to hold cash and pay over time.

Disclosure?

Must be disclosed in California (Mello-Roos), Texas (MUD/PID districts), Florida (CDD), and many others. Always pull disclosure docs during acquisition — un-disclosed bonds add 0.5-2% of value to annual tax burden.

How often should I rerun this?

Rerun this calculator whenever inputs change materially — new rent roll data, rate moves, loan balance updates, or quarterly operating data. For active deals, monthly refresh is typical. For stabilized assets under monitoring, quarterly is fine. Treat the output as a decision tool, not a one-time answer — market conditions evolve and so should your analysis.