Indiana does not run a reappraisal cycle the way Ohio does. Instead, it relies on annual trending factors — multipliers applied to each commercial parcel's prior-year base assessed value to bring it in line with the latest sales-disclosure data. If you own commercial real estate in Indiana, trending is the quiet engine that pushes your AV up (or down) year after year, even when nothing changed on the building. The 2026 trending cycle is the first one where post-pandemic commercial sales have fully washed through the data, and the results vary sharply by market.
What "Trending" Actually Means
Trending is Indiana's shortcut for keeping assessments current without ordering a full statewide reappraisal every year. Under IC 6-1.1-4, assessors take the prior year's base assessed value, multiply by a neighborhood-level trending factor derived from recent arm's-length sales in that market area, and then adjust for any new construction or demolition on the parcel. The output is your 2026 gross AV — the number that appears on Form 11 and that the 3% commercial circuit breaker is calculated against.
The factors themselves are set at the neighborhood or market-area level, not at the individual parcel. That is the point of friction commercial owners run into most often: your property may have lost income or occupancy, but if the neighborhood's sales pool ticked up, the factor went up and so did your AV. The corrective is a property-specific appeal, not a complaint about the factor itself — and our assessment vs. market value resource explains why that distinction matters at the PTABOA.
How the DLGF Derives the 2026 Factors
The Department of Local Government Finance oversees county assessors' sales-ratio studies. Each assessor stratifies parcels into neighborhoods or market areas, compares the prior-year AV of recently sold parcels to the actual sale price reported on the Sales Disclosure Form, and calculates a median ratio. If the median ratio drifts below the statutory target band, the trending factor goes up to push AV back toward market. If the ratio drifts above the band, the factor goes down. The DLGF reviews and certifies the factors before they are applied — but the methodology is only as good as the underlying sales pool, and thin or stale pools are exactly where 2026 errors are emerging.
Two specific cracks recur. First, a small neighborhood with only two or three commercial sales in the study period can be skewed by a single distressed or arm's-length-questionable transaction. Second, the "market area" can be drawn so broadly that a Class-A office is being trended against Class-B/C sales — pulling its AV in the wrong direction. Both are appealable, and both reward an owner who actually reads the sales-ratio worksheet before deciding whether to file Form 130.
Where 2026 Trending Pushes AV Higher
Growth markets are seeing the biggest upward factors. The Indianapolis donut counties — Hamilton County and Hendricks and Boone — are still absorbing strong industrial and flex sales from 2024 and 2025, and the 2026 factors for those neighborhoods are climbing accordingly. New industrial construction in the I-65 and I-70 corridors has anchored a broader sales pool that is pulling existing parcels up with it. For owners of older industrial buildings, that means a 2026 AV that may not match the property's actual functional condition.
Inside Marion County, mixed-use and apartment sales have been uneven, but trending in Center Township and the near-north neighborhoods is generally pointing up. The interaction with the cap matters: when a Marion County commercial parcel is already pinned to the 3% cap, every point of trending pushes the cap ceiling itself higher, which means an automatic bill increase the next cycle. Read our Marion County page for the local appeal channels and timing.
Where 2026 Trending Pushes AV Lower
Not every market is up. Northwest Indiana's older industrial inventory in Lake County has seen softer sale prices on functionally obsolete buildings, and several neighborhoods inside Gary, Hammond, and East Chicago show declining factors for 2026. Rural retail in outlying counties — particularly older single-tenant standalones — is also drifting down. If your 2026 Form 11 actually shows a reduction, do not assume it is enough. The statewide trending floor for some commercial categories has not kept pace with how far rents and NOI have moved, and the property-specific math may still support a further reduction via Form 130.
The Cap Interaction Owners Miss
Indiana's constitutional 3% commercial circuit breaker is the most-cited reason owners think trending does not matter to them. It does. The cap is calculated as 3% of gross assessed value — not of market value, and not of a fixed base. When trending raises your gross AV, it also raises the dollar ceiling of the cap. A property whose bill was already capped at $120,000 in 2025 against a $4M AV will be capped at $126,000 in 2026 against a 5%-trended $4.2M AV. The cap did not break; the cap moved. Our Indiana tax caps page works through that math in dollars.
What to Do When Your 2026 Form 11 Arrives
First, calculate the implied trending factor. Pull last year's gross AV, subtract any value attributable to new construction or demolition recorded in 2025, and divide this year's base into that figure. The remainder is the factor. Then ask the county assessor for the sales-ratio worksheet that supports it. The worksheet shows which sales were included, which were thrown out as non-market, and which neighborhoods were grouped. That worksheet is the single most valuable document you can request before deciding to appeal.
Second, compare the trended AV to a defensible market value. That is where the EPTA free assessment review earns its keep — we cap-rate the property's actual NOI, compare to recent arm's-length sales, and flag where the trending factor has overshot. Third, if the math supports a reduction, file Form 130 within the statutory window (45 days from Form 11 mailing, or June 15, whichever is later) with the township or county assessor.
Common Trending Errors We See in 2026
The biggest error is the "snap-back" — when an assessor trends from the original pre-appeal AV instead of the reduced AV that PTABOA or IBTR actually awarded the year before. The statute does not authorize this, but it happens in practice when assessors rebuild their rolls from base data rather than carrying forward the determination. Second is misclassified market area: a property pulled into the wrong neighborhood pool, trended against the wrong sales. Third is double-counting — applying both a trending factor and a construction-related value add for the same improvement. Each of these is a winnable Form 130 issue, and all three require careful review of the prior-year file alongside the new notice. Our broader 2026 Indiana assessment changes post adds context for what else is shifting beyond trending.
