Indiana Property Tax Cap Calculator (1-2-3 Constitutional Caps + Homestead)

How this calculator works

Indiana is one of the only states in the country with property tax caps written directly into the state constitution. Article 10 § 1(f) of the Indiana Constitution caps the total property tax bill at a fraction of gross assessed value: 1% for owner-occupied homestead, 2% for other residential and farmland, 3% for non-residential. The caps were added by the 2008-2010 legislative process and ratified by voters in November 2010 as Public Question 1, taking effect for tax year 2010 and fully phasing through 2012.

The math has two paths and the binding constraint is the lower of the two:

• Deduction-based path: gross AV minus standard homestead, supplemental homestead, over-65, and blind/disabled deductions yields net assessed value. Net AV times the district tax rate is the gross tax before the cap.
• Constitutional cap path: gross AV times the cap rate (1%, 2%, or 3%) is the cap ceiling. Final tax cannot exceed this ceiling regardless of how high local district rates rise.

In high-rate districts (Marion, Lake) the cap binds for most homesteads — the deduction-based tax would be well above 1% of gross AV without the constitutional ceiling. In low-rate districts (Hamilton, Boone, many rural counties) the deductions are economically full-value and the cap rarely binds.

The 1-2-3 constitutional caps (Art. 10 § 1(f))

The 2007 Marion County reassessment produced property tax bills that doubled or tripled for many homestead owners, triggering a statewide reform movement. The legislative response wrote the caps directly into the constitution so that no future legislature could quietly unwind them. The caps:

| Property class | Cap rate | Applies to | | --- | --- | --- | | Homestead | 1% | Owner-occupied primary residence with the standard homestead deduction filed | | Other residential / ag | 2% | Non-homestead rentals, second homes, agricultural land, long-term care facilities | | Non-residential | 3% | Commercial, industrial, personal property |

The cap is computed against gross assessed value — not net AV after deductions. A $250,000 homestead cannot pay more than $2,500 in total property tax regardless of the district rate. The cap reduces revenue to local taxing units (counties, school corporations, libraries, townships); the unrecovered amount is called the circuit-breaker loss in Indiana budget reporting.

How Indiana assessed values are determined

Indiana uses market value-in-use under IC 6-1.1-31, set annually by the county assessor. Market value-in-use approximates fair market value for the parcel's current use — typically derived from comparable sales for residential parcels and from income or cost approaches for commercial. There is no separate "assessment ratio" applied (unlike Arizona's class ratios at 10% / 16% or Michigan's 50% SEV). Gross AV is intended to equal market value-in-use directly.

The annual Form 11 Notice of Assessment is mailed in the spring. Appeal deadlines are typically 45 days from the notice. Indiana also performs a periodic cyclical reassessment under IC 6-1.1-4-4.2 that re-baselines values every several years. Pull gross AV from the county auditor's parcel record or the DLGF parcel viewer.

The deduction stack — and why order matters

The Indiana deduction stack is computed sequentially, with each step depending on the prior:

1. Standard homestead deduction (IC 6-1.1-12-37): the LESSER of $48,000 or 60% of gross AV. Available only for owner-occupied primary residences with Form HC10 filed.
2. Supplemental homestead deduction (IC 6-1.1-12-37.5): computed on (gross AV − standard deduction): 25% of the first $600,000 plus 35% of any amount above $600,000.
3. Over-65 deduction (IC 6-1.1-12-9): an additional $14,000 if owner age 65+, gross AV at or below $240,000, AND AGI at or below $30,000 single / $40,000 joint.
4. Blind/disabled deduction (IC 6-1.1-12-11): an additional $12,480 if legally blind or totally disabled AND taxable gross income under $17,000.

Two structural points that trip up new owners:

• The supplemental deduction is computed on post-standard AV (not on gross AV). Computing it on gross AV produces a number ~25% too high.
• The over-65 deduction has THREE conditions that must all be met. The $240K gross AV cap is the binding constraint for many central-Indiana homes today; a $300K Hamilton County home is not eligible even with a 70-year-old owner on a fixed $25K income.

A worked example — $250K Indianapolis homestead at 4% district rate

A $250,000 homestead in a Marion County township with combined district rate 4.0%. Owner is 40, single, $50K AGI, no disability.

• Standard homestead: min($48,000, 60% × $250,000) = $48,000
• Post-standard AV: $250,000 − $48,000 = $202,000
• Supplemental homestead: 25% × $202,000 = $50,500
• Over-65: $0 (owner is 40)
• Blind/disabled: $0
• Total deductions: $98,500
• Net AV: $250,000 − $98,500 = $151,500
• Tax before cap: $151,500 × 0.040 = $6,060
• Cap ceiling (1% homestead): $250,000 × 0.01 = $2,500
• Cap binds. Final tax = $2,500
• Savings from cap: $6,060 − $2,500 = $3,560

The owner pays roughly $3,560 less per year than the deduction-only path would produce. The cap is doing the heavy lifting; the deductions are economically irrelevant for the final bill because the cap binds first. This is the typical Marion / Lake County experience — high district rates plus the constitutional cap produce a flat 1% of gross AV effective rate for most homesteads.

A worked example — $400K Carmel (Hamilton) homestead at 2.0% district rate

A $400,000 homestead in Hamilton County with combined district rate 2.0%. Owner is 45, no other deductions.

• Standard homestead: $48,000
• Post-standard AV: $352,000
• Supplemental homestead: 25% × $352,000 = $88,000
• Total deductions: $136,000
• Net AV: $264,000
• Tax before cap: $264,000 × 0.020 = $5,280
• Cap ceiling: $400,000 × 0.01 = $4,000
• Cap binds. Final tax = $4,000

Even Hamilton's much lower 2.0% district rate produces a deduction-based tax above the 1% constitutional ceiling for a $400K home, so the cap still binds. The effective rate is 1.00% of gross AV — the constitutional ceiling.

A worked example — $150K rural homestead at 1.5% district rate

A $150,000 homestead in a low-rate rural county with combined district rate 1.5%.

• Standard homestead: $48,000
• Post-standard AV: $102,000
• Supplemental homestead: 25% × $102,000 = $25,500
• Total deductions: $73,500
• Net AV: $76,500
• Tax before cap: $76,500 × 0.015 = $1,147.50
• Cap ceiling: $150,000 × 0.01 = $1,500
• Cap NOT binding. Final tax = $1,147.50
• Effective rate: $1,147.50 / $150,000 = 0.765%

In this rural scenario the deductions are economically full-value — every dollar of deduction reduces the final tax. The cap is not binding because the deduction stack already pushes the tax well below the 1% ceiling. The effective rate of 0.77% is roughly the floor on what Indiana homesteads actually pay; rates much below this require either very low district rates, very low AV, or both.

A worked example — $1M homestead in the supplemental 35% bracket

A $1,000,000 homestead at the default 2.5% district rate. Owner is 50, no over-65 or disability deductions.

• Standard homestead: $48,000
• Post-standard AV: $952,000
• Supplemental homestead: 25% × $600,000 + 35% × $352,000 = $150,000 + $123,200 = $273,200
• Total deductions: $321,200
• Net AV: $678,800
• Tax before cap: $678,800 × 0.025 = $16,970
• Cap ceiling: $1,000,000 × 0.01 = $10,000
• Cap binds. Final tax = $10,000

The 35% supplemental tier kicks in for the portion of post-standard AV above $600,000 — an additional 10 percentage points of deduction on the upper bracket. The total supplemental of $273,200 is 27% of gross AV by itself; combined with the standard $48,000 the homestead deductions reach 32% of gross AV. Even so, the constitutional cap binds for high-value Indiana homesteads at the default 2.5% rate.

A worked example — $1M commercial parcel (3% cap)

A $1,000,000 commercial parcel in a Marion-style 4.0% district. No homestead deductions apply.

• Standard / supplemental: $0 (commercial is not homestead-class)
• Net AV: $1,000,000
• Tax before cap: $1,000,000 × 0.040 = $40,000
• Cap ceiling (3% non-residential): $1,000,000 × 0.03 = $30,000
• Cap binds. Final tax = $30,000

Commercial parcels pay at the 3% cap — three times the homestead cap. The structural feature is intentional: the constitutional drafters held homesteads to 1% specifically to protect owner-occupied primary residences from local rate inflation, while leaving commercial and industrial parcels at 3% to preserve a larger share of the local tax base.

A worked example — senior homestead with over-65 deduction

A $200,000 homestead. Owner is 70, single, AGI $20,000. Default 2.5% district rate.

• Standard homestead: $48,000
• Post-standard AV: $152,000
• Supplemental homestead: 25% × $152,000 = $38,000
• Over-65: $14,000 (age 70 ≥ 65; AGI $20K ≤ $30K single; gross AV $200K ≤ $240K cap)
• Total deductions: $100,000
• Net AV: $100,000
• Tax before cap: $100,000 × 0.025 = $2,500
• Cap ceiling: $200,000 × 0.01 = $2,000
• Cap binds. Final tax = $2,000

The over-65 deduction stacks on top of the homestead deductions, but in this case the constitutional cap still binds — the deduction-based tax of $2,500 is above the $2,000 cap. The over-65 deduction is economically irrelevant for the final bill in any scenario where the cap binds; it only adds value in low-rate districts where the cap is non-binding.

County district rate variation

Indiana district rates are assembled from overlapping taxing jurisdictions: county + township + school corporation + library + city or town + special districts (fire, conservancy, transit). Rates are expressed per $100 of net assessed value. Typical ranges by major county:

• Marion County (Indianapolis): 3.5–5.5% — urban townships at the higher end; the cap binds for most homesteads
• Lake County (Gary, Hammond, Merrillville): 3.0–5.0% — high-rate; cap binds frequently
• Allen County (Fort Wayne): 2.0–3.0% — mid-range; cap binds for some parcels
• Hamilton County (Carmel, Fishers, Noblesville): 1.5–2.5% — low-rate; cap rarely binds for homesteads
• Boone, Hendricks, Hancock (Indianapolis suburbs): 1.8–2.8% — mid-range
• St. Joseph County (South Bend): 2.5–4.0% — high-rate; cap often binds
• Vanderburgh County (Evansville): 2.5–3.5% — high-rate; cap often binds
• Rural counties: 1.5–2.5% — generally low-rate; cap rarely binds for homesteads

Pull the binding rate for the specific parcel from the county treasurer's annual tax certification. The DLGF parcel viewer also publishes per-parcel rate breakdowns.

Filing Form HC10 — and why timing matters

The standard homestead deduction is filed on Form HC10 with the county auditor of the county where the property is located. Required documentation: owner's name, property address, social security numbers of all owners (used for the homestead-uniqueness audit — one homestead per person statewide), proof of ownership (deed), and a declaration that the property is the owner's principal place of residence.

The filing deadline is December 31 of the year preceding the tax year the deduction is to apply for. New owners who close mid-year must file before December 31 to receive the deduction for the following tax year. Once approved, the deduction continues automatically year-over-year; the auditor periodically requests verification (typically every 4-5 years).

A common gap: a closing attorney does not flag the homestead filing requirement at closing, the new owner misses the December 31 deadline, and the homestead deduction (and 1% cap eligibility) is deferred by a full year. The unnecessary tax cost can be $1,500-$3,000 depending on the property value and district rate.

How Indiana's caps compare to other states

Indiana's caps are structurally different from year-over-year caps in other states. Most state caps limit the year-over-year growth in assessed value (a long-tenure protection that compounds over time but does nothing for a new buyer). Indiana's caps limit the absolute tax bill as a fraction of gross AV (a per-year protection that applies equally to new and tenured owners).

| State | Cap type | Cap value | Applies to | | --- | --- | --- | --- | | Indiana (Art. 10 § 1(f)) | Absolute, % of gross AV | 1% / 2% / 3% | All property; per class | | California (Prop 13) | Annual growth in AV | 2% | All real property | | Florida (Save Our Homes) | Annual growth in AV | 3% | Homestead only | | Arizona (Prop 117) | Annual growth in AV | 5% | All real property | | Texas (§ 23.23) | Annual growth in AV | 10% | Homestead only | | Most Midwest / Northeast | None | n/a | n/a |

The two protections solve different problems. Arizona's 5% Prop 117 protects a long-tenured owner from market spikes but does nothing for a new buyer in year one. Indiana's 1% homestead cap protects every homestead owner from high local district rates regardless of tenure. A new buyer in Indianapolis pays at most 1% of gross AV from day one — a stable, predictable maximum.

Common errors to avoid

• Computing the supplemental deduction on gross AV instead of post-standard AV. The supplemental is computed on (gross AV − standard deduction), not on gross AV. The error inflates the deduction by ~25% of the $48,000 standard, producing a $12,000 overstatement of total deductions on a typical homestead.
• Forgetting to file Form HC10 after a purchase. New owners must file before December 31 of the year preceding the tax year. Missing the deadline costs the homestead deduction AND the 1% cap eligibility for a full year — often $1,500-$3,000 of unnecessary tax.
• Applying the cap to net AV instead of gross AV. The constitutional cap is computed on gross AV by design. Computing on net AV would unwind the protection in homestead cases where deductions are large.
• Assuming the over-65 deduction is automatic. The over-65 deduction requires age 65+, gross AV at or below $240K, AND AGI at or below $30K single / $40K joint. The $240K AV cap excludes many central-Indiana homes; the income limits exclude many retirees with adequate retirement savings.
• Treating the cap as a tax reduction. The cap is a ceiling, not a reduction. It only changes the bill when the deduction-based tax exceeds the ceiling. In low-rate districts the cap is irrelevant.
• Confusing Indiana's 1-2-3 caps with year-over-year caps in other states. Indiana's caps limit the tax bill as a fraction of gross AV. They do not limit the year-over-year growth in AV — assessed values can rise as much as the market rises, and the cap simply ensures the bill never exceeds the constitutional ceiling.

Tools, not advice. Confirm the binding gross assessed value from the county auditor's Form 11 Notice of Assessment, the district tax rate from the county treasurer's annual tax certification, and all deduction eligibility with the county auditor before relying on any result for planning purposes.