King County, WA · 7,471 properties with county records
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Mercer Island 98040 is in King, WA, part of the Seattle Metro. The typical home value in Mercer Island 98040 is $2,212,672 (Zillow Home Value Index, September 2026), down 0.8% from a year earlier. Homes that sold went under contract in a median 11 days, and 11% of listings took a price cut (Redfin Data Center, period ending Sep 30, 2026). On Lotvox's market-leverage reading of that data, with 3.5 months of supply, sellers hold the advantage. The Lotvox Turnover Index is not published for 98040 yet: it appears only where a held-out test on the county's recorded sales beats chance. Across King's 80 ZIPs with a Zillow value, the middle one is $812,279, so 98040 sits 172% above the county middle. Typical rent is $2,796 a month (Zillow Observed Rent Index, September 2026). Lotvox holds county assessor records for 7,471 properties in 98040.
Headline value data through September 2026. Each source below carries its own date.
Is 98040 a buyer's or seller's market?
By Lotvox's leverage reading of Redfin data through Sep 30, 2026, 98040 is a seller's market. Homes went under contract in a median 11 days with 3.5 months of supply.
What do homes in 98040 sell for?
The typical home value in 98040 is $2,212,672 (Zillow Home Value Index, September 2026), down 0.8% in a year. That is a value index, not a list of sale prices.
Who is likely to sell in 98040?
Lotvox only publishes its Turnover Index where a held-out test on recorded sales beats chance, and 98040 has not passed that test yet. When it does, the score appears here.
How does 98040 compare to King?
98040's typical value of $2,212,672 compares with a middle value of $812,279 across King's 80 ZIPs. Both are Zillow Home Value Index figures for September 2026.
Where does this 98040 data come from?
Values and rents come from Zillow's research data, sales pace from the Redfin Data Center, and property counts and turnover from county assessor and deed records. Each number on this page carries its own date, and the method is published at lotvox.com/methodology.
Cite as: Lotvox ZIP market record, 98040 Mercer Island, WA, data through September 2026, https://lotvox.com/seattle/zip/98040
Listings Flow Ladder — 98040
Faucet, basin and drain — new listings in, active inventory, closed sales out.as of Sep 30, 2026
the basin is fillingnet 9 listings/mo
Faucet — new listings
31/mo
85% of normal (37) · trickle
Basin — active listings
75
89% of normal (84) · low· baseline thin
Months of supply
3.5 mo
derived — not published at this grain
Drain — closed sales
22/mo
58% of normal (37)
Net — faucet minus drain
+9/mo
filling
Reading
current
as of 2026-09-30
Compare against:2015-01-01 to 2019-12-31 · 5 same-month points
How plugged is the drain? Two definitions, both ours, deliberately not reconciled.
40%Absorption vs its own normal— 1 - (closed sales / active listings) / same-month median of that ratio
42%Closed sales vs its own normal— 1 - closed sales per month / same-month median closed sales per month
Closed sales over 24 months — two different numbers, deliberately not merged.
7/mofall in the monthly rate (24%)— peak 28/mo (2025-07-31) to 22/mo now
265transactions that did not happen— summed monthly shortfall vs the same-month normal, over 24 months below it (vs 2015-19 (COVID excluded))
rate_drop_from_peak is a change in the monthly rate; cumulative_shortfall_vs_normal counts transactions not transacted. They are different quantities and are not interchangeable.
2026-09-30
Redfin market data (county + ZIP), via Lotvox. As of 2026-09-30. Normal = same-month median of monthly rates, minimum 3 same-month points. Source window 3 months (flows shown per month). months_of_supply is not published at this grain (0 non-null rows measured); derived here as active listings / closed sales per month. A fresher supply-only read (24 new, 85 active, 2026-09-01, Realtor.com inventory (county + ZIP), via Lotvox) is available but is NOT used in the net — that source publishes no closed sales, so subtracting across it would mix two vintages.
Should you buy here?
buyer-timing lens
0affordability /100
Buyer leverage is seller advantage; weigh payment burden and the 3-lens valuation before bidding.
Payment burden
72.1%
severe
Days on market
11
daily
Price cuts
11.1%
of active
Valuation
+105.9%
vs assessor
Days on market and price cuts: Redfin Data Center, rolling 90 days.
Rent: Zillow Observed Rent Index (ZORI). Ownership cost: Zillow Home Value Index (ZHVI), 20% down, 30-year loan at the current mortgage rate, plus 1.2% of the price a year.
Rent to price — the investor's question first
65.9×
price to annual rent
Lower is friendlier to a buy-to-let case. This is a ratio of published medians, not a yield on any particular property.
Price: Zillow Home Value Index (ZHVI). Annual rent: 12 months of Zillow Observed Rent Index (ZORI).
Verdict grades housing conditions; buyer-timing, investor cash-flow, supply-tightness and county macro scores answer different questions — each in its own section.
Buyer / seller
buyer-timing lens
Negotiate Hard
Needs 58.4% correction for affordability
DOM: 60d (rising) · Market Dynamics rolling median · hourly
Score Components
Payment Burden (25%)100
Valuation Gap (25%)25
Supply & Demand (20%)100
Buy vs Rent (15%)100
Cancellation Rate (10%)0
Days on Market (5%)60
Moderate buyer leverage in 98040. Room to negotiate 5-10% below list. Payment burden: 69.8% of median income. A 50% price correction needed to reach 30% affordability threshold. Median days on market: 60. Renting is approximately 509% cheaper than buying (price-to-rent ratio: 73.1).
What to Offer
Offer 5-10% below list. You have room to negotiate.
Median price: Zillow Home Value Index (ZHVI). Median rent: Zillow Observed Rent Index (ZORI). Days on market and active listings: Redfin Data Center, rolling 90 days.
Valuation
3 lenses, different anchors
vs assessor
+105.9%
Market vs assessed value — a tax-roll lag, not a deal signal.
Avg assessor$4,555,500
county CAMA · properties_v
vs income
—
Fair-value model not available for this market.
fair_value_scores · 10-state coverage
vs county comps
+67.6%
County-wide market — the widest, slowest signal.
King+67.6%
Lotvox comps · mv_valuation_gap
Read together: Above county comps but sustainable on local incomes.
in 23,473 · out 29,819 · King County, WA (parent county of this ZIP)
active inventory
as of 2026-07-01 · IRS SOI county-to-county migration flows 2022-2023 + Redfin inventory history
Price bands
mix-shift
Price Bands — the median behind the median
A single median rises whenever expensive homes become a bigger share of what sells, even if no tier got more expensive. These are the tiers underneath it, computed from recorded arms-length deed transactions in King.
Current tiers · 12 months to Aug 25floor 10 sales/tier
1 tier had too few sales in this ZIP and are shown at county or metro level — see the stamp on each row. 6 tiers had too few sales at every level and are left blank rather than estimated.
Tier
Median
$/sqft
Sales
Share
Source
Under $250k
—
—
—
—
fewer than 10 sales at zip, county and metro level
$250k–$500k
$400k
$202
12
80.0%
COUNTY · King, WA
$500k–$750k
—
—
—
—
fewer than 10 sales at zip, county and metro level
$750k–$1M
—
—
—
—
fewer than 10 sales at zip, county and metro level
$1M–$1.5M
—
—
—
—
fewer than 10 sales at zip, county and metro level
$1.5M–$2M
—
—
—
—
fewer than 10 sales at zip, county and metro level
$2M+
—
—
—
—
fewer than 10 sales at zip, county and metro level
All sales (the headline median)
$412k
$210
15
100%
COUNTY · King, WA
No mix-shift history for this area. no geography from this ZIP up to metro has 8+ quarters of 10+ recorded arms-length sales across at least 4 price tiers. Trends are drawn only from recorded transactions; the last-sale snapshot above cannot carry a time series, because a property that sold twice keeps only its latest sale — which drags the history upward through the tiers and would invent the very mix shift this section exists to test for.
National context — not local
NAR's aggregate existing-home median for the United States and the West census region. This is the figure the tiers above are a check on. It is national/regional and says nothing about 98040.
United States
West
Copyright, National Association of Realtors. Reprinted with permission. Retrieved from FRED, Federal Reserve Bank of St. Louis. FRED publishes a rolling 13-month window for these series.
Tiers computed from Lotvox parcel and deed substrate through Aug 25 (10 later months withheld as partially loaded). Sample floor 10 sales per tier; below it a figure is drawn from the county or metro and labelled, or left blank. Multi-parcel bulk deeds and duplicate records are excluded.
ZIP score grades housing; county score adds macro distress (jobs, debt, poverty). They answer different questions.
ZIP 98040→King County, WA
12-Month Direction
-17Moderate Deterioration
Confidence
100%
DeterioratingStableImproving
BuildersLens Market Intelligence
Market Score
35· Weak
Market Score grades housing-market conditions (affordability, valuation, supply). The county Healthy/Moderate/Distressed badge measures economic distress (jobs, debt, poverty) — the two can read differently.
Payment Burden
72.1%
severe
Source: Freddie Mac PMMS (FRED MORTGAGE30US) 7.32% · Zillow ZHVI · Census income · Updated 2026-10-22
Price-to-rent
65.9x
favors renting
Source: Zillow ZHVI ÷ (Zillow ZORI × 12)
Valuation3
+67.6%
overvalued
Source: Lotvox comps · Updated 2026-05-15
Supply/Demand
3.5 mo
balanced
Source: Redfin Data Center (ZIP): inventory ÷ monthly homes sold · Updated 2026-09-30
Insurance Risk
38/100
moderate
Source: FEMA/NFIP · Updated 2026-04
County distress indicators
ECONOMIC INDICATORS
Economic indicators are mixed relative to comparable U.S. counties.
Unemployment Rate
4.7%
WA 5.2%US 4.4%
Near national averages
Source: BLS LAUS · 2026-0857d ago
Poverty Rate
8.8%
WA 10.3%US 12.6%
Lower than most U.S. counties
Median Household Income
$122,148
WA $97,733US $82,006
Higher than most U.S. counties
Cost of Living (RPP)
107.5
WA 107.5US 100.3
Near national averages
Home Value (ZHVI)$866,580
County data: Zillow Home Value Index (ZHVI), BLS, Census ACS, CDC, FBI UCR, Federal Reserve, USDA
Typical home value: Zillow Home Value Index (ZHVI); change is the 12-month change.
Owner stock, age of householder
Tenure by age of householder (ACS B25007) is not published below county. Any ZIP figure here is DERIVED from the county's age-specific owner rates applied to this ZIP's own age structure — never read directly.
Derived — this ZIP
17.2% in 2023
of owner-occupied homes have a householder 75 or older
