For over a decade, the standard advice to Indiana homeowners considering rooftop solar included a property tax sweetener: a state deduction that effectively kept the panels off your assessed value. That advice is now out of date, and a lot of websites haven't caught up. If you installed panels recently — or you're deciding whether to — here is how Marion County assessment actually treats residential solar in 2026, what the 2025 legislature did to the old deduction, and what to do if your assessment jumped after installation.
One scope note up front: this post is about panels on your house. Utility-scale solar farms are assessed under an entirely different regime — capped regional land base rates plus depreciating utility personal property — which we covered in our guide to how Indiana assesses solar farms, wind farms, and battery storage.
How a rooftop system enters your assessment
Indiana assesses homes at market value-in-use, and improvements reach the tax roll the way any home improvement does: through permits and inspections. A solar installation typically requires an electrical or building permit, and a permit is a signal to the township assessor that something changed on the parcel — the same pipeline that catches new construction in Marion County. Whether the assessor actually adds value for panels varies in practice: cost schedules, the assessor's judgment about what the system contributes to market value, and simple data lag all play a role. Some systems never visibly move an assessment; others show up as a line on the record card.
What changed in 2025 is what happens after that value lands.
The solar deduction: what existed, and what SEA 1 did
Indiana law long provided deductions that neutralized renewable systems for property tax purposes: IC 6-1.1-12-26 for solar energy heating and cooling systems, and IC 6-1.1-12-26.1 for solar power devices (photovoltaic panels), alongside parallel deductions for wind, geothermal, and hydroelectric systems. The deduction equaled the assessed value attributable to the system — you filed State Form 18865 (Form SES/WPD) with the county auditor, and the system's value was effectively removed from your taxable base. The form still appears on the DLGF's deduction forms page.
Then came SEA 1-2025. As part of its broad restructuring of deductions, it eliminated the renewable energy deductions retroactive to the January 1, 2025 assessment date. The DSIRE incentive database entry for Indiana's renewable energy property tax exemption now records the statute as applying only to assessment dates before January 1, 2025, with the provision expiring entirely on January 1, 2027. The DLGF laid out the assessment-side changes in its May 2025 legislative guidance memo.
Warning
Many solar-marketing sites still advertise the Indiana property tax deduction as an active incentive. It is not, for the 2025 assessment date forward. Bills payable in 2026 are the first computed without it. If a sales quote for a new system includes Indiana property tax savings from IC 6-1.1-12-26, that line is stale — verify anything tax-related with the county auditor, not the installer.
To be equally honest in the other direction: the repeal removed the offset, not your panels' invisibility. Per the DLGF guidance discussed in our utility-scale solar post, removing the deduction should not itself change your gross assessed value — the repeal doesn't instruct assessors to go add value for systems they weren't already valuing. If your gross AV was flat and only the deduction line vanished, that is the law working as (re)written, not an assessment error.
What this means for your 2026 bill
Three scenarios cover most Marion County homeowners with panels:
| Your situation | What to expect in 2026 |
|---|---|
| Had the deduction on file before 2025 | The deduction no longer applies from the 2025 assessment date forward; your bill reflects whatever AV the system carries |
| Installed in 2024 or earlier, never filed | Nothing to file now — the deduction is closed for current assessment dates |
| Installing in 2026 | No state property tax deduction applies; budget on your assessment as-is |
There is nothing left to file with the auditor for rooftop solar on current assessment dates. That moves all of the action to the assessment side — making sure the value on your record card is right. The rest of the deduction landscape that does survive is in our complete exemptions and deductions list.
If solar triggered an assessment bump
A post-installation jump in assessed value is appealable like any other, and the legal standard works in your favor: Indiana assessments must reflect market value-in-use, not the cost of the system. Solar installations are a textbook case where cost and market value diverge — what you paid the installer is not evidence of what the panels add to your home's sale price, and resale contribution depends heavily on system age, ownership versus lease, and buyer demand in your neighborhood.
If your Form 11 or record card shows a solar-driven increase you think overshoots:
- Pull the record card and isolate what the assessor actually added — an improvement line, a grade change, or a lump. You cannot contest a number you haven't decomposed.
- Check for double counting. A common error pattern is an added improvement value plus an upward adjustment elsewhere justified by the same installation.
- Build the market case. Sales of comparable homes with and without panels in your township are the strongest evidence that the addition overstates market contribution.
- File a Form 130 with the Marion County Assessor by the statutory deadline: June 15 of the assessment year if your Form 11 mailed before May 1, or June 15 of the following year if it mailed later. The process and timelines are in our 2026 appeal guide, and what happens after filing covers the PTABOA path.
Tip
Leased systems and third-party-owned panels deserve extra scrutiny on the record card. Equipment you do not own, on a roof you do, is exactly the kind of fact pattern where an assessor's data entry outruns the legal analysis. If a leased system was added to your real property assessment, raise it with the township assessor before assuming it belongs there.
Verify what your panels are costing you
Verify rather than guess: pull your parcel's assessed value history with Property Lookup and check whether your assessment moved after your installation went in — the year-over-year view makes a solar-driven bump obvious. Start from the Marion County explorer if you're comparing neighborhoods, and if the number looks wrong, our tax appeal service can build the comparable evidence and file the Form 130.