Indiana Annual Adjustment and the Form 11 Notice

Indiana is the only state on this site with no reassessment cycle at all. Since 2002, county assessors apply annual adjustment — “trending” — every year, using that year’s sales data to move area values toward market. There is no six-year clock like Ohio’s, no eight-year ceiling like North Carolina’s, and therefore no year in which a big jump can be dismissed as “the reassessment.”

How trending works

Two layers produce each year’s value:

1. Mass appraisal characteristics. The assessor’s record of your property — age, grade, condition, size, features — produces a base value under the state’s rules, expressed as market value in use.
2. The sales study. Each year’s arm’s-length sales in your area determine whether neighborhood values should move toward market — upward or downward. The adjustment is applied area-wide, not parcel by parcel.

Before the values are certified, the Department of Local Government Finance (DLGF) reviews and approves each county’s assessment-to-sales ratio study — the statistical check that the county’s assessments actually track sales. This state-level approval is Indiana’s structural answer to the question other states answer with equalization boards and ratio deadlines.

The two notice routes — and why the difference matters

Notice of your assessment arrives one of two ways, and the 45-day appeal clock attaches to either:

• Form 11 — the notice of assessment. Mailed by the county assessor when the law requires individual notice (new construction, an assessment increase of more than 5%, and other triggers). If you receive one, your appeal window runs 45 days from its date.
• The tax bill (TS-1) itself. Where no Form 11 is issued, the tax bill serves as the notice of assessment — the state’s own FAQ states it plainly. The window becomes the later of May 10 of the tax-bill year or 45 days after the bill’s date.

The DLGF’s Citizen’s Guide adds the June 15 framing: contact the local assessor by June 15 of the year you receive a Form 11 — or June 15 of the following year when none was mailed. The two framings describe the same window from different starting points; the notice or bill you actually hold controls your own date.

Worked example (illustrative)

Illustrative dates with made-up figures — not your property.

1. Inputs: 2026 assessment $260,000 after a year in which the neighborhood trended up; last year $245,000 (+6.1%).
2. Step — the notice: because the increase exceeds 5%, a Form 11 is mailed, dated April 10, 2027.
3. Step — the window: 45 days from April 10 is May 25, 2027 — that is the deadline to initiate the appeal (see the Form 130 page).
4. Step — the burden: because the increase exceeded 5%, the burden of proof at the appeal is the county’s, not yours — the single most owner-favorable rule in the Indiana system.

What this tells you: a Form 11 in the mailbox is both a notice and a warning about who carries the burden — a 5%+ increase shifts it to the county. And since trending moves values every year, checking whether a Form 11 arrived is an annual task, not a once-a-cycle one.

What it does not tell you: whether the trend was correctly applied to your neighborhood (a ratio-study question), or what your bill will be — the circuit breaker may cap it regardless of the assessment (see the caps page).

What this page does not cover

The technical rules of the DLGF’s ratio-study review and the real property assessment guidelines’ valuation formulas are outside this page. The DLGF pages cited below are the authorities for the cycle and the notice routes.