Every Marion County parcel carries a three-digit property class code. It is easy to assume that number decides your tax cap. It does not. The code describes what the property is; your cap tier depends on how Indiana law categorizes the property's use and whether a homestead deduction is on file. Knowing the difference tells you which office can fix an error.
What the class code actually means
The codes come from Appendix A of the DLGF 2021 Real Property Assessment Manual. The first digit is the broad class: 1 agricultural, 3 industrial, 4 commercial, 5 residential, 6 exempt, 8 utility. The residential codes most Marion County owners see:
| Code | Manual definition |
|---|---|
| 500 | Vacant platted lot |
| 510 | One family dwelling on a platted lot |
| 511 | One family dwelling on unplatted land of 0 to 9.99 acres |
| 512-515 | One family dwelling on larger unplatted acreage (10 acres and up) |
| 520 / 521 | Two family dwelling (platted lot / unplatted 0-9.99 acres) |
| 530 / 531 | Three family dwelling (platted lot / unplatted 0-9.99 acres) |
| 550 | Condominium unit on a platted lot |
| 599 | Other residential structures |
None of these codes says "rental" or "owner-occupied." A 511 is a single-family house on unplatted land, whether it is a homestead, a rental, or a second home. Larger apartment buildings sit in the commercial class: 401 (4 to 19 family apartments), 402 (20 to 39 family), and 403 (40 or more family).
In the state's IGIO parcel boundary dataset as loaded into AribaTax's database, Marion County has 345,353 parcels. Of those, 246,891 carry code 510, 16,030 carry 511, 9,051 carry 520, 18,987 carry 550, and 1,337 carry 401, 402, or 403.
What actually sets your cap tier
Indiana's circuit breaker credit under IC 6-1.1-20.6-7.5 limits the tax attributable to each kind of property to a share of gross assessed value: 1% for a homestead, 2% for residential property, long term care property, and agricultural land, and 3% for nonresidential real property and personal property. The definitions control, not the code:
- Homestead (1%) means a homestead that has been granted the standard deduction under IC 6-1.1-12-37 (IC 6-1.1-20.6-2). No deduction on file, no 1% cap, even if you live there.
- Residential property (2%) includes a single family dwelling that is not part of a homestead, a building with two or more dwelling units plus its common areas and land, and land leased for manufactured homes (IC 6-1.1-20.6-4). It excludes hotels, motels, inns, and tourist camps or cabins.
- Nonresidential real property (3%) is everything that is not a homestead, residential, long term care, or agricultural land (IC 6-1.1-20.6-2.5).
So a 403 apartment complex carries a commercial class code yet qualifies for the 2% cap because it is a building with two or more dwelling units. For background, see Indiana's tax caps explained and Indianapolis cap exposure.
How a wrong cap tier really happens
1. The homestead deduction is missing. This is the most direct route from 1% to 2%. You claim the deduction by filing a certified statement with the county auditor, by January 15 of the year the taxes are due (IC 6-1.1-12-37(e)-(f)). New buyers who never filed, deeds moved into a trust or LLC, and deductions removed after an audit all produce the same result. See our homestead deduction guide, new homeowner checklist, and trust and LLC rules.
2. The use changed and the record did not. If you stop living in a house and rent it out, you must notify the auditor within 60 days (IC 6-1.1-12-37(g)); failing to do so creates liability. Read about audits and penalties before assuming a lost deduction is a mistake.
3. The use is misdescribed. A building with apartments recorded as purely commercial can land in the 3% tier when the statute puts it at 2%.
4. Mixed-use split errors. The credit is computed on the liability attributable to each property type, so a storefront with apartments above depends on how the residential and nonresidential portions are separated. A wrong split moves dollars between the 2% and 3% tiers.
Note
Hypothetical example, not a real parcel. A house with $250,000 of gross assessed value has a 1% cap of $2,500 as a homestead and a 2% cap of $5,000 without the deduction. The cap is a ceiling: if your rate times net assessed value comes out lower, the cap does not change your bill.
How to check your record
Pull your Marion County property record card from the Marion County Assessor, or use MapIndy and county tools. Check three things:
- Class code against reality. Is it the right dwelling type (one, two, or three family; condo; apartments)? Is the platted or unplatted designation correct?
- Homestead deduction status on your tax bill. If you live there and it is missing, that is the first fix.
- Mixed-use parcels. Confirm residential units are recorded.
The correction route
Homestead problems go to the auditor first. The deduction is filed with the county auditor, and under IC 6-1.1-15-12.1(c) an auditor may correct errors regarding a tax cap, credit, exemption, or deduction upon discovery. Those corrections cannot reach back further than the immediate three prior years (IC 6-1.1-15-12.1(h)).
Formal appeals use Form 130, page 2. IC 6-1.1-15-1.1(a) lets you appeal the approval, denial, or omission of a deduction, credit, exemption, abatement, or tax cap; a clerical, mathematical, or typographical mistake; and the description of the property. Those claims can be filed up to three years after the taxes were first due, unlike value appeals, which carry the June 15 deadline. The DLGF appeals page says these "objective" claims go on page 2 of Form 130, and that refunds also require a Claim for Refund (Form 17T).
The statute does not list "class code" as a separate ground; a code that misdescribes your property fits the clerical-mistake or description claims, and a missing homestead fits the deduction and tax-cap claim.
In Marion County, Form 130 goes to the county assessor, because no township assessors remain. If the informal meeting does not resolve it, the PTABOA hears it. See what happens after filing, the hearing evidence guide, and the correction-of-error guide. Once you win, here is how refunds work.
Find Your Property
Use our property lookup to see your parcel's class code and record details. If your deduction, use, or cap tier looks wrong, our tax appeal service can help you build the correction claim.