Buying in Ada County, Idaho

Ada County at a glance

Ada County is one of 44 counties and county-equivalents in Idaho. Its county seat is Boise. County government publishes its offices and parcel tools online. Official county website. With a 2024 Census Bureau population estimate of 535,799, it is the most populous county in Idaho. In the FBI's 2024 reported-crime file, agencies here reported 5,496 offenses — 10.26 per 1,000 residents; the breakdown is below.

Records to check before you buy in Ada County

• Property record card — the Ada County assessor / appraisal office. Pull the parcel's assessed-value history, exemption status, and last sale. This is the file your future tax bill is calculated from, and it shows whether the current owner is enjoying exemptions you will not inherit. County government sits in Boise; the official county website is the reliable route to the parcel search and the office directory.
• Deeds & liens — the Ada County recorder / land-records office. Read the deed chain, open liens, easements, and plat maps — the file a listing never mentions.
• Official flood determination. Check the exact parcel on FEMA's National Flood Hazard Layer — not the listing site's licensed model. Zone boundaries cut through streets; the house next door can be in a different zone. Ada County is the primary county for 16 ZIP codes in the Census Bureau's ZIP-to-county crosswalk — and zone lines ignore every one of them.
• The county's reported-crime record. In the FBI's 2024 file, agencies in Ada County reported 5,496 offenses — 10.26 per 1,000 residents; the largest single category was larceny-theft (3,317). The crime section below sets that beside the Idaho county median.
• Registry check. Run the address through Idaho Sex Offender Registry (Idaho SOR) (Idaho State Police) and note the counts within a mile — then check again the week you close.
• Permits & code history — the Ada building department. Open permits, expired permits, and code cases tell you whether the renovation in the photos was ever inspected. County permitting is run out of Boise.
• School assignment — the district office, not the listing. Only the district's own boundary lookup confirms which school an address is actually zoned for.

County list, land area and population: U.S. Census Bureau (population: 2024 PEP estimate). County seat and official website: Wikidata (CC0), checked 2026-11-04. Flood determinations: FEMA. Registry: Idaho.

Reported crime in Ada County — FBI 2024

Agencies in Ada County reported 5,496 offenses to the FBI in 2024 — 1,305 violent and 4,191 property offenses. That works out to a reported-crime rate of 10.26 per 1,000 residents (violent 243.6, property 782.2 per 100,000).

Inside Idaho, the median county in the same file recorded a violent-crime rate of 204 per 100,000 and a property-crime rate of 474 per 100,000 (medians computed from the FBI 2024 county file across 44 counties).

The largest reported categories were larceny-theft (3,317), aggravated assault (911) and motor vehicle theft (445).

Coverage: 6 of 6 law-enforcement agencies assigned to this county reported at least one month of 2024 offense data to the FBI; 5 reported all 12 months. Counts are reported offenses only (FBI Return A / Arson master files), assigned whole to each agency's primary county; they are not adjusted for non-reporting agencies.

These are offenses reported to law enforcement — not convictions, and not a verdict on any street or address. A CurbFacts report pairs this county record with the ZIP-level picture for the specific address you are buying.

Source: FBI Crime Data Explorer, UCR Return A + Arson master files, data year 2024 (pulled 2026-11-04).

The Idaho rules that apply in Ada County

Traps researched for Idaho buyers: Homeowner's exemption ends when the home sells; Brand-new homes are largely exempt from disclosure.

Read the full Idaho guide — disclosure standard, tax math, registry and flood

More Idaho counties

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