ADA & Reasonable Accommodation Rules in Illinois 2026

Two federal duties sit at the center of every disability request an Illinois landlord receives, and Illinois layers its own statutes on top of them. A reasonable accommodation is a change to a rule, policy, or service, such as waiving a no-pets policy or assigning an accessible parking space, and the housing provider absorbs the cost. A reasonable modification is a physical change to the unit or common area, such as a grab bar or a ramp, and under federal law the tenant generally pays. Both come from the federal Fair Housing Act (42 U.S.C. 3604(f)), which applies to nearly all Illinois rentals regardless of size. On top of that baseline, the Illinois Human Rights Act (775 ILCS 5) makes disability discrimination in housing a civil rights violation, and the Assistance Animal Integrity Act (310 ILCS 120) spells out exactly when you can and cannot ask for documentation on a support or service animal. Refusing a valid request, or over-documenting one, is where landlords get charged.

What Illinois Law Adds

Adds sexual orientation, gender identity, marital status, military status, ancestry, age 40+, order of protection status, source of income (HB 2775, 2022).

Accommodation vs. modification: who pays in Illinois

The cost split follows federal law, and Illinois does not shift it. Under 42 U.S.C. 3604(f)(3)(B), a reasonable accommodation is a change to your rules, policies, practices, or services, and you bear any cost of that change. Waiving a no-pets rule for an assistance animal, letting a tenant with limited mobility have a reserved space near the entrance, or accepting rent from a representative payee are accommodations; you cannot bill the tenant for them.

A reasonable modification under 42 U.S.C. 3604(f)(3)(A) is a structural change, and the disabled tenant pays for it. You must permit the work when it is necessary for the tenant to fully use the home, but you are not required to fund it. For a rental, you may, where it is reasonable, condition permission on the tenant agreeing to restore the interior to its prior condition when they leave, ordinary wear and tear excepted. That restoration condition only reaches changes that would interfere with the next tenant's use; you cannot demand removal of a widened doorway or lowered countertop that the next occupant would not object to. The Illinois Human Rights Act, 775 ILCS 5, imposes parallel duties and is enforced by the Illinois Department of Human Rights, so a request that fails under one law usually fails under the other.

The interactive process you owe every requester

A request does not have to use the words "reasonable accommodation," cite a statute, or come in writing. Under Illinois Department of Human Rights guidance on the Illinois Human Rights Act (775 ILCS 5), once a tenant makes a request, you must respond regardless of when or how it was communicated. Ignoring it, delaying without reason, or forcing the tenant to re-file counts as a constructive denial.

Run a short, documented dialogue. Confirm the request is tied to a disability and confirm the requested change is what meets the disability-related need. If the disability and the need are obvious, you take the request at face value. If they are not obvious, you may ask for verification of the disability and the disability-related need, but you may not demand a diagnosis, medical records, or the details of the condition. Where a requested change is unusually costly or difficult, propose an alternative that also meets the need rather than refusing outright; the law expects a good-faith exchange, not a yes-or-no gate. Keep dated notes of every request, response, and offer.

Assistance animals under the Assistance Animal Integrity Act

Illinois goes further than the federal baseline here. The Assistance Animal Integrity Act (310 ILCS 120), effective January 1, 2020, defines an assistance animal as an emotional support or service animal that qualifies as a reasonable accommodation under the federal FHA or the Illinois Human Rights Act. Because the animal is an accommodation and not a pet, you must waive a no-pets policy and you may not charge a pet fee, pet rent, or a pet deposit for it. You may still hold the tenant responsible for actual damage the animal causes.

The documentation rule is strict. You may require reliable documentation of the disability and the disability-related need only when the disability or the need is not readily apparent or already known to you. When someone uses a guide dog and their need is obvious, you cannot demand paperwork. Acceptable documentation flows from a therapeutic relationship, defined in 310 ILCS 120 as care provided in good faith, with actual knowledge of the person's disability and need, by a physician or medical professional, a mental health provider, or a non-medical service agency or reliable third party in a position to know. For a request involving more than one animal, you may ask for documentation establishing the need for each animal unless that need is apparent. Illinois law also makes it unlawful to misrepresent an animal as an assistance animal or to knowingly supply fraudulent documentation, which gives you a lawful basis to reject a facially bogus letter, but not a basis to disbelieve a properly sourced one.

When a denial is defensible

A refusal survives scrutiny only on narrow grounds. You may deny a request that is not disability-related or not actually necessary to give the tenant equal use of the housing. You may deny one that imposes an undue financial and administrative burden, judged against your resources, not a flat dollar rule, or one that would require a fundamental alteration of your operations, such as providing personal care you do not offer any resident.

For assistance animals specifically, you may deny or revoke approval when the specific animal poses a direct threat to the health, safety, or property of others that cannot be reduced by another reasonable accommodation, or when the animal shows a pattern of uncontrolled behavior the handler has not corrected. Breed, size, and weight limits do not apply to assistance animals, and a generalized fear of a breed is not a direct threat. Before denying on burden or fundamental-alteration grounds, offer any workable alternative; a bare refusal without exploring alternatives is the pattern the Illinois Department of Human Rights treats as discrimination.

Documentation and process that keeps you out of a charge

Most Illinois fair-housing charges turn on how the landlord handled the request, not on the underlying facts. Build a repeatable file. When a request arrives, log the date and how it came in. Decide first whether the disability and need are obvious; if they are, act without asking for paperwork. Only when they are not obvious do you request reliable documentation, and you request the need, not the medical diagnosis.

Respond in a reasonable time and in writing. If you grant the request, confirm the terms; for a modification, spell out any restoration condition and, where appropriate, that the work must be done in a workmanlike manner with any required permits. If you deny, state the specific lawful ground and the alternative you offered. Never charge a fee tied to an assistance animal, never require a specific form of ESA letter or a particular provider, and never treat a delay as a soft no. A landlord who documents a good-faith interactive process, honors the federal cost split, and follows the Assistance Animal Integrity Act's documentation limits has a defensible file if a charge is ever filed with the Illinois Department of Human Rights or HUD.

Illinois Service-Animal Misrepresentation Statute

This statute is generally enforced in public-accommodation contexts (restaurants, retail) rather than as part of a landlord-tenant dispute. For housing, the practical landlord defense against a fraudulent ESA claim is to require reliable documentation from a healthcare professional with a therapeutic relationship to the tenant, not to attempt criminal enforcement.

The Cost of Mishandling a Reasonable-Accommodation Request

The most common mistake in Illinois reasonable-accommodation cases is responding with a flat denial, "no pets means no pets", instead of engaging in the interactive process. The interactive process is itself a substantive duty. A landlord who refuses to consider the request, demands more than HUD permits, or imposes a pet fee on an assistance animal will lose at HUD even if the underlying accommodation could have been reasonably denied.

Reasonable Modification, Often Confused With Accommodation

Reasonable modification (42 U.S.C. § 3604(f)(3)(A)) is a structural change, a grab bar, a ramp, lowered cabinets. The tenant pays. The landlord must permit the modification and may require restoration to original condition at move-out (except for changes that would not significantly affect re-rental). Reasonable accommodation is a change to a rule or policy. The landlord pays no out-of-pocket cost; the cost is administrative. Illinois follows the federal rule.

City-Level Eviction Risk in Illinois

Reasonable-accommodation litigation rates correlate with overall tenant-protection enforcement. View landlord risk and tenant-law profile by city:

Sources & Methodology

• Federal Fair Housing Act: 42 U.S.C. § 3604(f)(3)(A) and (B); 24 C.F.R. § 100.204; 24 C.F.R. § 180.671 (civil penalties).
• ADA service animals: 28 C.F.R. § 36.302 (Title III, public accommodations).
• HUD guidance: HUD/DOJ Joint Statement on Reasonable Accommodations (May 17, 2004); HUD FHEO Notice 2020-01 (Jan 28, 2020).
• Illinois fair-housing statute: 775 ILCS 5/3-101 et seq. (Illinois Human Rights Act).
• Illinois misrepresentation statute: 720 ILCS 630/0.01.

Related Guides for Illinois Landlords

This overview reflects the federal Fair Housing Act (42 U.S.C. 3604(f)), the Illinois Human Rights Act (775 ILCS 5) enforced by the Illinois Department of Human Rights, and the Illinois Assistance Animal Integrity Act (310 ILCS 120), current as of 2026. It is general information for housing providers, not legal advice. Statutes and agency guidance change, and how a rule applies depends on the specific request, the property, and the tenant's circumstances. Before denying a request or imposing a restoration condition, confirm the current statute text and consult a fair-housing attorney or the Illinois Department of Human Rights.

Frequently Asked Questions

Does the tenant or the landlord pay for a disability modification in Illinois?

For a structural modification, the tenant pays. Under 42 U.S.C. 3604(f)(3)(A) you must permit a reasonable modification necessary for the tenant to use the home, but the tenant funds it, and for a rental you may reasonably require restoration of the interior at move-out, ordinary wear and tear excepted. A reasonable accommodation, which is a change to a rule or policy rather than a physical change, is your cost under 42 U.S.C. 3604(f)(3)(B).

Can I charge a pet deposit or pet rent for an emotional support animal in Illinois?

No. Under the Assistance Animal Integrity Act (310 ILCS 120) and the federal Fair Housing Act, an assistance animal is a reasonable accommodation, not a pet, so you cannot charge a pet fee, pet rent, or pet deposit and you must waive a no-pets policy. You may still charge the tenant for actual damage the animal causes.

When can I ask an Illinois tenant for documentation of an assistance animal?

Only when the disability or the disability-related need is not readily apparent or already known to you. Under 310 ILCS 120 you may then require reliable documentation of the disability and the need, drawn from a therapeutic relationship with a physician, mental health provider, or a non-medical agency or reliable third party in a position to know. You cannot demand a diagnosis or medical records.

What are the lawful reasons to deny a request in Illinois?

You may deny a request that is not disability-related or not necessary, one that imposes an undue financial and administrative burden, or one that would fundamentally alter your operations. For an assistance animal, you may also deny when the specific animal is a direct threat to health, safety, or property that no other accommodation can reduce, or shows uncorrected dangerous behavior. Denials should be paired with any workable alternative.

Does a request have to be in writing to count?

No. Illinois Department of Human Rights guidance under the Illinois Human Rights Act (775 ILCS 5) requires you to respond to a request regardless of how or when it was made. A verbal request or a note from a family member can trigger the duty. Putting your own response in writing is good practice, but you cannot require the tenant to use a particular form.

What if I think an ESA letter is fake?

Illinois law makes it unlawful to misrepresent an animal as an assistance animal or to knowingly provide fraudulent documentation, which lets you reject a facially bogus submission. But that is not license to disbelieve documentation that comes from a genuine therapeutic relationship as defined in 310 ILCS 120. If the letter is properly sourced and the need is stated, treat the request as valid rather than second-guessing the provider.

Federal authority: 42 U.S.C. § 3604(f); 28 C.F.R. § 36.302; HUD FHEO Notice 2020-01. State authority: 775 ILCS 5/3-101 et seq. (Illinois Human Rights Act); 720 ILCS 630/0.01. Last updated October 23, 2026. For informational purposes only, not legal advice. Reasonable-accommodation determinations are highly fact-specific; consult a licensed Illinois attorney before denying any request.