Miami County: How Grissom Air Reserve Base Shapes Peru's Tax Base

Miami County in north-central Indiana is structured around two anchors: the city of Peru as county seat, and Grissom Air Reserve Base roughly ten miles south of Peru. Grissom — the largest employer in the county — sits on federal land that's exempt from local property tax. That exemption has shaped Miami's tax base for decades and continues to shape how the 2026 assessment cycle plays out for surrounding parcels in Peru, Bunker Hill, and the unincorporated portions of Harrison, Pipe Creek, and Jefferson townships.

For Miami owners, the 2026 cycle brings the same statewide changes hitting every county: the SB 1 supplemental homestead credit capped at $300, the supplemental homestead deduction step-up from 35% to 40%, and the DLGF cost-table reset that drove statewide AVs up roughly 12% in 2025. Miami-specific items — the Grissom Aeroplex, the federal exemption footprint, and the rural-residential mix — layer on top.

Grissom Air Reserve Base spans Cass and Miami counties. The base proper is federal property and exempt from local tax. The adjacent Grissom Aeroplex, a redevelopment district managed by the Miami County Economic Development Authority, includes parcels that may be on the tax rolls depending on lease and ownership structure.

How a Federal Installation Shapes a County's Tax Base

When a large federal installation sits inside a county, three structural effects show up in the local tax data:

Reduced Taxable AV Density

Land that would otherwise carry residential, commercial, or agricultural AV instead carries no AV. In Miami, the federal footprint reduces total taxable AV by an amount large enough to be material to the county's per-capita levy distribution. The county compensates through rate calibration on the remaining taxable parcels.

Service-Demand Spillover

Federal installations consume some local services (roads to and from the base, emergency response, schools for dependent children) without contributing to the local levy that funds them. The federal government provides Payments In Lieu of Taxes (PILT) for some of this, but PILT typically covers a fraction of the equivalent property tax revenue.

Concentrated Economic Activity

A base of Grissom's size anchors a substantial portion of local employment and ancillary economic activity. That activity drives demand for nearby residential and commercial property — putting upward pressure on AVs in Peru, Bunker Hill, and the surrounding unincorporated areas.

For the 2026 assessment cycle, the practical takeaway is that Miami's residential AV base is doing more per dollar than in counties without a large federal exempt footprint.

What the 2026 Statewide Changes Do in Miami

SB 1 $300 Homestead Credit

For a Peru homestead paying $1,200–$1,800 a year, the SB 1 credit is roughly $120–$180 — the 10% bill reduction.

Supplemental Deduction Step-Up

35% to 40% of post-standard-deduction AV. For most Miami homesteads not at the 1% cap, this is a quiet but real reduction in taxable base.

DLGF Cost-Table Reset

Miami residential parcels tracked the state at roughly 12% AV growth for 2025-pay-2026. Commercial parcels — particularly along the US 31 corridor — saw above-median pressure reflecting the construction-cost rebuild.

Peru Homestead Math

For a typical Peru homestead with a $135,000 AV at Miami's typical rate range:

Step	Calculation	Amount
Gross AV	—	$135,000
Less standard deduction	$48,000	$87,000
Less supplemental (40%)	40% × $87,000	$34,800
Net AV	—	$52,200
Tax rate (illustrative)	~$22 / $1,000	—
Gross tax	$52,200 × 0.022	$1,148
1% cap test	1% × $135,000	$1,350 (cap not binding)
Pre-credit	min(gross, cap)	$1,148
SB 1 credit	10% × $1,148, max $300	$115
Final annual tax	$1,148 − $115	$1,033

This is illustrative — actual Miami rates vary by taxing district. The pattern: Peru homesteads typically sit below the cap, so the SB 1 credit applies at the 10% rate.

Form 11 Items for Miami Owners

The 2026 Form 11 mails statewide on April 28. Miami-specific items to verify when it arrives, on top of the statewide Form 11 walkthrough:

Item	Why it matters in Miami
Year-over-year AV change	Anything over 12–15% on a stable parcel deserves a closer look
School corporation	Miami includes Maconaquah, North Miami, Peru, Oak Hill (parts) — verify match
Class code	Rental-frequent areas near the base sometimes get drift-coded as 510
Floodplain status	Wabash River and tributaries cross the county
Homestead status	Military families with frequent moves sometimes lose homestead temporarily

The Grissom Aeroplex and Its Parcels

The Grissom Aeroplex is a redevelopment district adjacent to the federal base. Some Aeroplex parcels are leased back from the federal government to private operators, and some are owned outright by the Miami County Economic Development Authority for redevelopment. The tax status varies parcel by parcel:

Federal-owned, leased to private operator: assessment and tax treatment depend on lease terms; some lease structures trigger leasehold assessment
County EDA owned, leased to private operator: similar leasehold treatment
Privately owned within the Aeroplex footprint: standard property tax assessment

For commercial operators in or near the Aeroplex, the practical advice is to verify the assessment basis with the county before assuming the property is treated like a comparable parcel elsewhere in the county.

Filing an Appeal in Miami

Miami's PTABOA caseload is moderate — appeals here typically resolve in 4–8 months. The process, covered fully in the Indiana property tax appeal guide:

File Form 130 with the Miami County Assessor's Office
Include 3–5 comparable sales from your specific neighborhood code
Document any condition issues with photos
For income-producing property: rent roll and operating statement
For Aeroplex-adjacent parcels: verify the comparable set excludes federal-exempt land
Filed by June 15, 2026 or 45 days from the Form 11 mailing date

The trending sales window for the 2026 assessment runs January 2024 through January 2025.

Rural Residential Considerations

Outside Peru and Bunker Hill, much of Miami is rural residential and small-acreage agricultural. For rural Miami parcels, the 2026 Form 11 may show a separation between:

Homesite valuation — the immediate residential building site (typically 1–2 acres)
Agricultural land valuation — surrounding acreage at the state-mandated agricultural use value
Improvement valuation — house, outbuildings, garages

For the homesite valuation specifically, the same SB 1 credit and supplemental deduction apply. The agricultural land portion is assessed separately at the agricultural use value formula, which is set at the state level rather than tracked to local market.

Miami At a Glance

Metric	Miami County
Population (est.)	~36,000
Total parcels	~25,000
County seat	Peru
Major federal footprint	Grissom Air Reserve Base
School corporations	Maconaquah, North Miami, Peru, parts of Oak Hill
Spring 2026 bill due	May 11, 2026
Form 11 mails	April 28, 2026
Appeal deadline	June 15, 2026 (or 45 days from Form 11)

What to Do This Spring

For Peru-area homestead owners: open the Form 11 the day it arrives, verify the five line items, and file Form 130 by June 15 if the AV looks unreasonable.

For owners near the Grissom Aeroplex: verify the parcel's tax status — federal-exempt, county EDA, or private — affects both the assessment basis and the appeal options.

For rural property owners: verify the homesite vs agricultural land split on the Form 11; misallocation between the two can shift the taxable base materially.

Property Lookup pulls Miami parcel data including the federal-exempt footprint, and Tax Appeal Automation builds the Form 130 + evidence package on contingency.