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FIPS: 47187•Rank #48 National•Rank #3 in TN
Williamson County, TN
Forward-Looking Municipal Debt, Assessment Lag & Carrying Cost Audit
Elevated Tax Drift Risk
96% Conf.
Tax Drift Index
58.9/ 100
Elevated Drift Risk
Williamson County Executive Risk Briefing
MSRB EMMA Disclosures & US Census BureauAugust 2026
Williamson County carries a Elevated Tax Drift Score (58.9/100) based on $7,400 in overlapping municipal debt per capita and a +28% CAD assessment lag spread. Projected 3-year millage escalation of +0.08% (+8 bps) indicates an estimated +$1,567/yr escrow adjustment on median-priced properties.
Median Home: $810,000Median Income: $122,000Effective Tax: 0.5%
Municipal Debt Per Capita
$7,400
6.1% of Median Income
CAD Valuation Lag
+28.0%
Assessed Value trailing Market HPI
3-Yr Millage Escalation
+8 bps
Effective Rate: 0.5% → 0.6%
Projected Annual Escrow Shock
+$1,567/yr
Estimated on median assessed home
Interactive Property Tax & Escrow Shock Simulator
Model forward-looking ad valorem tax obligations and monthly escrow adjustments for a specific parcel in Williamson County, TN.
$810,000
$0
Current Annual Tax
$4,212
@ 0.52% eff. rate
Year 3 Projected Tax
$5,779
@ 0.60% eff. rate
Net Escrow Increase
+$1,567/yr
+$131/mo mortgage escrow
Projected Shock Attribution Breakdown+8 bps rate shift
1. Muni Bond Debt Service
+4 bps
I&S bond amortization
2. Operating Deficit Drift
+4 bps
M&O budget expansion
3. CAD Valuation Catch-up
+$767/yr
+$147,420 assessed base
Overlapping Taxing Jurisdictions & Debt Obligations
Breakdown of autonomous debt issuers assessing ad valorem property taxes on parcels within Williamson County.
| Entity Name | Entity Type | Outstanding Bond Debt | Debt / Student or Cap | Adopted Millage |
|---|---|---|---|---|
| Williamson County Schools (TN) | ISD | $890.0M | $21,500 | 0.380% |
5-Year Historical Drift Score & Effective Rate Trajectory
2022
52
0.5% eff.
2023
54
0.5% eff.
2024
56
0.5% eff.
2025
58
0.5% eff.
2026
58.9
0.5% eff.
Statutory Constraint & Legislative Policy
Franklin and Brentwood affluent school districts fund aggressive facility expansions under low nominal certified tax rates.
Data Provenance & Audit Citations