The Marion County Assessor's Office has added nearly $2 billion in assessed value across approximately 1,000 apartment complexes with 20 or more units. If you own or manage multifamily property in Indianapolis, your 2026 tax bill is about to look very different — and the appeal deadline is June 15, 2026.
This isn't an isolated local decision. It's the result of statewide changes to how Indiana values property, and more increases are already locked in for 2027.
What Happened
The Indiana Department of Local Government Finance (DLGF) made two changes that drove this surge:
1. Removed Downward Base Rate Adjustments
For years, the DLGF applied a downward adjustment to its base cost tables — essentially a discount that kept assessed values below raw replacement cost. For the January 1, 2025 assessment date (taxes payable in 2026), the DLGF removed this downward adjustment, causing base rates for all property types to jump significantly.
2. Increased Apartment Base Rates Again for 2026
The DLGF then doubled down, increasing base rates specifically for apartments for the January 1, 2026 assessment date (taxes payable in 2027). The agency updated its cost tables using data from a third-party vendor, resulting in higher base construction costs for multifamily properties.
The result is back-to-back years of significant base rate increases — creating enormous two-year jumps in assessed values for apartment owners who haven't appealed.
The Scale of the Increase
Across Marion County, approximately 1,000 apartment complexes with 20 or more units saw substantial increases. The aggregate increase of roughly $2 billion in assessed value translates to significant individual tax bill increases.
This is part of a broader statewide trend. From 2024 to 2025, Indiana's gross assessed values rose across every property class:
Commercial property — which includes apartments — saw the largest percentage increase statewide. Marion County, as Indiana's largest county by population and property base, absorbed a disproportionate share of the total increase.
What This Means for Landlords
Higher Tax Bills
At Marion County's tax rates, a $1 million increase in assessed value translates to roughly $20,000-$30,000 in additional annual property taxes, depending on the specific taxing district. For large complexes with multi-million dollar assessment increases, the tax impact can reach six figures.
Rental and agricultural properties are capped at 2% of assessed value under Indiana's circuit breaker system. For apartments already near the cap, the increased assessment pushes them firmly against it — meaning the full theoretical tax increase may be partially offset by the cap. But properties below the cap will feel the full impact.
Partial Relief from SB 1
Senate Bill 1 introduced a new deduction for rental housing, starting at 13.3% in 2026 and phasing to 33.4% by 2031. For a $5 million apartment complex, that's a $665,000 deduction in year one.
However, the new deduction only partially offsets the base rate increases. Landlords should not assume that SB 1 makes them whole — the net effect for most complexes is still a significant tax increase.
Impact on Renters
Indiana does not have rent control, and property taxes are a standard operating expense that landlords factor into rent pricing. Higher property tax bills on apartment complexes will inevitably put upward pressure on rents across Indianapolis.
The DLGF has acknowledged this tension, recognizing that tenants struggling with affordability concerns should not bear the full burden of large property tax assessment increases. But the mechanism for relief runs through the appeal process, not through automatic adjustments.
The Appeal Deadline: June 15, 2026
For Indianapolis taxpayers, the spring 2026 tax bill is your official notice of the 2025 assessed value increase. The deadline to file a Form 130 appeal is June 15, 2026. Missing this deadline forfeits your right to challenge the 2025 assessment.
If your apartment complex received a significant assessment increase, you should evaluate whether an appeal is warranted. The key question: does the new assessed value reflect the property's actual market value?
Grounds for Appeal
An appeal can succeed if you can demonstrate that your property's assessed value exceeds its market value. Common arguments for apartment complexes include:
Income approach: If the assessed value implies a capitalization rate that's below market cap rates for comparable properties, the assessment may be too high. Indianapolis apartment cap rates generally range from 5.5% to 7.5% depending on class and location. An assessment that implies a 4% cap rate is likely over-valued.
Comparable sales: If similar apartment complexes in your area have sold for less per unit than your assessed value implies, you have evidence of over-assessment.
Physical condition: If your complex has deferred maintenance, functional obsolescence, or other issues not reflected in the cost-based assessment, you may be entitled to additional depreciation.
Our step-by-step appeal guide covers the Form 130 filing process in detail. For apartment owners, AribaTax's Tax Appeal Automation can analyze your property's assessment against market data and income metrics.
What's Coming in 2027
The DLGF has already increased apartment base rates again for the January 1, 2026 assessment date (taxes payable in 2027). This means even if you successfully appeal your 2025 assessment, you may face another increase on the next cycle.
Apartment owners should consider:
- Filing appeals annually — each assessment year is independent, and a successful appeal for one year doesn't carry forward automatically
- Documenting property condition — maintain records of capital expenditure needs, deferred maintenance, and functional issues
- Tracking market data — keep records of comparable sales, rental rates, and vacancy in your submarket
Statewide Context
The apartment assessment surge in Indianapolis is part of a broader statewide reassessment cycle. While Marion County absorbed the largest absolute increase, similar dynamics are playing out across Indiana's 92 counties.
Counties with significant multifamily housing stock — including Lake County, Allen County, St. Joseph County, and Vanderburgh County — are all seeing increased commercial and residential assessed values.
The 12% statewide growth in assessed values reflects both the DLGF's base rate adjustments and genuine market appreciation in many areas. For apartment owners, separating legitimate market-driven increases from cost-table-driven increases is the key to a successful appeal.
How AribaTax Can Help
AribaTax maintains assessment data for all 3.7 million Indiana parcels, including commercial and multifamily properties. Our tools can help apartment owners:
- Property Lookup — Check your current assessment and compare to neighboring properties
- Tax Appeal Automation — Analyze whether your assessment exceeds market value and file a Form 130
- AI Valuation — Get an independent estimate of your property's market value
- Investor Tools — Analyze cap rates, cash flow, and tax burden across counties
Related Reading
- Indiana SB 1 property tax reform — New rental deduction and levy freeze details
- How to appeal your assessment — Step-by-step Form 130 guide
- Buying rental property in Indiana — County-by-county investment analysis
- Most over-assessed counties — Where assessments deviate most from market value