Which one fits your situation?
Short version: if your animal isn’t task-trained, you’re probably looking at an ESA. If it’s a task-trained dog for a mental-health disability, that’s a PSD — a type of service dog with full ADA access. The full version is the table below.
| ESA | PSD | Service Dog | Therapy Animal | |
|---|---|---|---|---|
| Definition | Provides emotional comfort by its presence. No task training required. | A dog individually trained to perform specific tasks tied to a psychiatric disability. | A dog individually trained to perform tasks for a physical or medical disability (mobility, guide, medical alert, etc.). | A domesticated animal trained to provide comfort to others (patients, students). Not a personal assistance animal. |
| Legal letter required? | Yes — for housing (FHA). | Yes — for housing, useful in disputes. | Not by law, but clinical documentation is usually helpful. | Credentialing varies by institution; not federally standardized. |
| Housing (FHA) | Protected. Landlords can't charge pet fees or refuse based on breed/size with a valid letter. | Protected, same as ESA. | Protected. | Not protected — therapy animals are not FHA assistance animals. |
| Airline cabin access | No — after the 2021 DOT rule, airlines aren't required to accommodate ESAs in-cabin. | Yes — as service dogs. Expect the DOT form + task documentation. | Yes. | No. |
| Public access (ADA) | No — ESAs are not covered by ADA public-access rights. | Yes — as service dogs. | Yes. | No. |
| Task training required? | No. | Yes — tasks directly related to the disability (e.g., interrupting panic, DPT, medication reminders). | Yes — tasks directly related to the disability. | Depends on the credentialing org (AKC, Pet Partners, Therapy Dogs Intl., etc.). |
| Species | Any common domestic animal. | Dog only (per ADA service-animal definition). | Dog (occasionally miniature horse). | Typically dog; some orgs certify other species. |
| What two questions can staff ask? | N/A — ESAs don't have public-access rights. | 1) Is the dog required because of a disability? 2) What task has the dog been trained to do? | Same two questions as PSD. | N/A — therapy animals don't have independent access rights. |
Not sure where you fit?
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Need a qualifying letter?
NSAR clinicians can evaluate you for an ESA or PSD letter in one business day or less.
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Sources: Fair Housing Act · HUD FHEO-2020-01 · DOT ACAA final rule (January 2021) · ADA.gov Service Animals Revised Requirements. This page is plain-English guidance, not legal advice.