Marion County Commercial & Industrial Assessments Add $5.5 Billion in 2026

The Marion County Assessor's Office has added approximately $5.5 billion in new assessed value across roughly 12,000 commercial and industrial parcels for the January 1, 2025 assessment cycle — the largest non-residential reassessment surge Indianapolis has seen in over a decade. The numbers come from a parcel-level survey of Marion's C&I roll showing an average increase of 27% and a median of 18%, with the upper quartile of properties seeing increases above 35%.

If you own a Marion County office building, warehouse, retail center, manufacturing facility, or any other commercial or industrial parcel, the impact lands on your spring 2026 tax bill — and the deadline to appeal is June 15, 2026.

This is a separate event from the $2 billion Indianapolis apartment assessment increase reported earlier this year. Apartments are taxed under a different methodology and reassessed on a separate base-rate schedule. C&I parcels — everything from a corner gas station to a Class A office tower — moved on the broader DLGF cost-table change.

Why the Numbers Moved

Two upstream changes at the Department of Local Government Finance drove the surge:

1. Removal of the Cost-Table Downward Adjustment

For years, DLGF applied a downward adjustment to its statewide base cost tables — a discount that kept mass-appraisal replacement costs below true construction-replacement value. For the January 1, 2025 assessment, DLGF removed that adjustment. Every property class felt it, but C&I felt it most because base costs are the dominant input on commercial cost-approach valuations (versus residential where market sales carry more weight).

2. Updated Cost Tables Using Third-Party Vendor Data

DLGF refreshed its construction cost tables using a third-party data vendor's 2025 cost survey. The new tables reflect post-pandemic construction cost inflation — roughly 30% higher than the pre-2020 baseline still embedded in the prior tables.

The combined effect: a 12,000-parcel sample showed average AV increases of 27% with a median of 18%. The right-skew (mean above median) means a meaningful tail of properties saw increases of 50% or more.

What This Looks Like on Your Tax Bill

Marion County C&I parcels are subject to the 3% circuit breaker cap. That means your 2026 bill cannot exceed 3% of your gross assessed value — which sounds like a ceiling, but in practice it's a floor for many high-rate properties because the cap moves up with AV.

Worked example: A 50,000 sq ft warehouse in Center Township:

The 3% cap doesn't insulate this owner from the AV increase — the cap simply rises 1:1 with AV. The full 27% AV increase passes through to the bill.

Appeal Math: When It Pays

For a 3%-capped property like a warehouse, the appeal economics are straightforward:

• Every dollar of AV reduction = 3 cents of annual tax savings
• A $500,000 AV reduction = $15,000 per year in tax savings
• That savings persists across multiple years until the next reassessment cycle

Compare against the cost of an appeal:

• DIY Form 130 with comparable cost data: $0 in fees, ~10–20 hours of work
• Property tax consultant on contingency: typically 30–50% of first-year savings
• Indiana-licensed attorney for a complex IBTR case: $5K–$25K depending on parcel value

For a Marion County C&I parcel where the AV jumped by $1M+ on the 2025 assessment, an appeal is almost always positive ROI. The June 15 deadline is hard.

How to Build the Case for a Marion C&I Appeal

The Indiana standard is market value-in-use — what your property is worth in its current use to a typical user. For C&I properties this is established through three approaches; you (or your representative) need to argue the one most favorable to your case.

Sales Comparison Approach

Best for owner-occupied retail, office condos, and small commercial buildings where market sales exist. Pull 3–5 sales from the trending window (Jan 1, 2025 – Dec 31, 2025) of similar parcels in Marion County. AribaTax's Property Lookup indexes every recorded Marion sale.

Income Approach

Standard for income-producing commercial — office, retail centers, industrial leased space. Capitalize stabilized net operating income at a market cap rate. The DLGF accepts this approach for C&I parcels and it often produces values well below cost-approach figures, especially in the current high-cap-rate environment.

Cost Approach (Replacement Cost Less Depreciation)

DLGF used the cost approach to increase your AV. You can use it to argue down by demonstrating excessive depreciation — functional obsolescence, external obsolescence (location, market headwinds), or condition issues that the mass-appraisal cost tables don't account for.

Marion County PTABOA: What to Expect

Marion's Property Tax Assessment Board of Appeals is the busiest in the state. Two practical realities:

1. Hearings are scheduled months out. The PTABOA cleared roughly 8,000 appeals in the prior cycle and is expected to receive significantly more this cycle. Expect a 6–12 month wait for hearing.
2. Most appeals settle on written evidence. A well-organized evidence package — comps, income statements, condition photos — frequently produces a settlement offer from the assessor's representative before the formal hearing.

While the appeal is pending, your required tax payment is based on the prior year's AV multiplied by the current rate. The disputed delta is escrowed until resolution. This is significant cash-flow relief for owners with large 2026 increases — the amount above last year's tax does not have to be paid pending appeal.

For the full Form 130 walkthrough, see our Indiana property tax appeal guide, and for the day-the-notice-arrives checklist, our Form 11 walkthrough.

Action Steps for Marion C&I Owners

1. Pull your 2026 Form 11 the day it arrives (mailing April 28, 2026) and confirm the year-over-year AV change
2. Cross-check against comparable sales and income data using Property Lookup
3. File Form 130 by June 15, 2026 — no exceptions, no extensions
4. Pay your 2026 spring installment based on the prior-year AV if your appeal is filed; the disputed amount is not due
5. Prepare for round two: the 2026 assessment cycle (taxes payable 2027) carries another DLGF base-rate increase. Position your evidence file now

For Tax Appeal Automation on contingency for any Marion County parcel, AribaTax handles the full Form 130 + evidence package + PTABOA representation cycle.

Marion County Resources

• Marion County overview — 2026 AV summary across townships
• Marion commercial parcel data
• Marion industrial parcel data
• Marion residential parcel data

Related Reading

• Indianapolis apartment assessments jump $2B
• Indiana property tax caps explained
• Indiana property tax appeal guide
• Indiana 2026 Form 11 notices: what to do
• Indiana SB 1 property tax reform