About this index & how it's been checked

The Aging Vulnerability Index (AVI) is this platform's own construction, modeled on the CDC/ATSDR Social Vulnerability Index methodology but not a CDC product and not independently validated. It combines Census ACS data on the population 65 and older — demographic aging pressure, economic precarity, health/disability/isolation, and housing/transportation burden — into a single percentile ranking of U.S. counties. The underlying inputs are official Census data; the index construction and weighting are this platform's own.

Reference-county check

A face-validity check against real counties with well-documented age profiles — the same method used to calibrate this platform's seasonal-community threshold. Higher percentile = more aging-vulnerable.

  • ✓ Sumter County, FL — 79.8th percentile (expected HIGH, The Villages — often cited as the oldest-median-age U.S. county)
  • ✓ Charlotte County, FL — 90.8th percentile (expected HIGH, Retirement destination)
  • ✓ Citrus County, FL — 88.1th percentile (expected HIGH, Retirement destination)
  • ✓ Highlands County, FL — 95.9th percentile (expected HIGH, Retirement destination)
  • ✓ Brazos County, TX — 17.0th percentile (expected LOW, Texas A&M)
  • ✓ Story County, IA — 8.9th percentile (expected LOW, Iowa State)
  • ✓ Whitman County, WA — 10.3th percentile (expected LOW, Washington State University)
  • ✓ Tompkins County, NY — 7.6th percentile (expected LOW, Cornell)

Highest / lowest AVI by county population

Under 50,000

Highest
  1. Catron County, NM — 100.0th pctile (pop. 3,743)
  2. De Baca County, NM — 99.9th pctile (pop. 1,576)
  3. Ozark County, MO — 99.8th pctile (pop. 8,873)
  4. Scott County, VA — 99.6th pctile (pop. 21,479)
  5. Harney County, OR — 99.6th pctile (pop. 7,499)
Lowest
  1. Martin County, TX — 0.0th pctile (pop. 5,218)
  2. Jim Hogg County, TX — 0.1th pctile (pop. 4,727)
  3. Haskell County, KS — 0.1th pctile (pop. 3,641)
  4. Hanson County, SD — 0.1th pctile (pop. 3,472)
  5. Trousdale County, TN — 0.2th pctile (pop. 11,957)

50,000-99,999

Highest
  1. Nye County, NV — 96.7th pctile (pop. 54,344)
  2. Gila County, AZ — 96.7th pctile (pop. 53,795)
  3. Raleigh County, WV — 96.0th pctile (pop. 73,195)
  4. Wilkes County, NC — 95.6th pctile (pop. 65,935)
  5. Pittsylvania County, VA — 94.0th pctile (pop. 59,856)
Lowest
  1. Oldham County, KY — 0.0th pctile (pop. 69,257)
  2. Eagle County, CO — 0.2th pctile (pop. 55,135)
  3. Lincoln County, SD — 0.5th pctile (pop. 70,638)
  4. Johnson County, MO — 0.9th pctile (pop. 54,732)
  5. Lafayette County, MS — 1.3th pctile (pop. 58,327)

100,000-299,999

Highest
  1. Highlands County, FL — 95.9th pctile (pop. 105,702)
  2. Mohave County, AZ — 93.9th pctile (pop. 220,517)
  3. Douglas County, OR — 93.0th pctile (pop. 112,072)
  4. Charlotte County, FL — 90.8th pctile (pop. 201,064)
  5. Indian River County, FL — 90.3th pctile (pop. 166,936)
Lowest
  1. Union County, NC — 0.8th pctile (pop. 250,958)
  2. Scott County, MN — 1.1th pctile (pop. 154,557)
  3. Williamson County, TN — 1.2th pctile (pop. 260,351)
  4. St. Mary's County, MD — 1.3th pctile (pop. 115,126)
  5. Dallas County, IA — 1.5th pctile (pop. 107,968)

300,000 and higher

Highest
  1. Pinellas County, FL — 90.1th pctile (pop. 963,481)
  2. Collier County, FL — 89.9th pctile (pop. 398,291)
  3. Marion County, FL — 87.1th pctile (pop. 400,078)
  4. Lee County, FL — 86.1th pctile (pop. 817,666)
  5. Palm Beach County, FL — 85.0th pctile (pop. 1,533,806)
Lowest
  1. Hamilton County, IN — 0.6th pctile (pop. 365,056)
  2. Prince William Count, VA — 2.1th pctile (pop. 488,880)
  3. Davis County, UT — 2.1th pctile (pop. 370,924)
  4. Douglas County, CO — 2.2th pctile (pop. 377,150)
  5. Loudoun County, VA — 2.4th pctile (pop. 432,998)
Compare

SD — Aging Vulnerability Index

Candidate index, not validated against ground truth — 2020–2024 ACS 5-year
SD — Aging Vulnerability Index by county
Aurora County — 42 (Middle)Beadle County — 55 (Upper-middle)Bennett County — 7 (Lower)Bon Homme County — 55 (Upper-middle)Brookings County — 2 (Lower)Brown County — 35 (Middle)Brule County — 79 (Higher)Buffalo County — 27 (Lower-middle)Butte County — 33 (Lower-middle)Campbell County — 93 (Higher)Charles Mix County — 74 (Upper-middle)Clark County — 85 (Higher)Clay County — 4 (Lower)Codington County — 54 (Upper-middle)Corson County — 26 (Lower-middle)Custer County — 33 (Lower-middle)Davison County — 86 (Higher)Day County — 97 (Higher)Deuel County — 39 (Middle)Dewey County — 21 (Lower-middle)Douglas County — 86 (Higher)Edmunds County — 41 (Middle)Fall River County — 96 (Higher)Faulk County — 54 (Upper-middle)Grant County — 44 (Middle)Gregory County — 88 (Higher)Haakon County — 78 (Higher)Hamlin County — 1 (Lower)Hand County — 92 (Higher)Hanson County — 0 (Lower)Harding County — 1 (Lower)Hughes County — 31 (Lower-middle)Hutchinson County — 51 (Upper-middle)Hyde County — 32 (Lower-middle)Jackson County — 16 (Lower)Jerauld County — 92 (Higher)Jones County — 69 (Upper-middle)Kingsbury County — 48 (Middle)Lawrence County — 68 (Upper-middle)Lincoln County — 1 (Lower)Lyman County — 55 (Upper-middle)McCook County — 21 (Lower-middle)McPherson County — 93 (Higher)Marshall County — 15 (Lower)Meade County — 3 (Lower)Mellette County — 5 (Lower)Miner County — 95 (Higher)Minnehaha County — 5 (Lower)Moody County — 43 (Middle)Oglala Lakota County — 26 (Lower-middle)Pennington County — 50 (Middle)Perkins County — 50 (Middle)Potter County — 41 (Middle)Roberts County — 72 (Upper-middle)Sanborn County — 53 (Upper-middle)Spink County — 44 (Middle)Stanley County — 75 (Upper-middle)Sully County — 18 (Lower)Todd County — 24 (Lower-middle)Tripp County — 76 (Higher)Turner County — 44 (Middle)Union County — 25 (Lower-middle)Walworth County — 65 (Upper-middle)Yankton County — 38 (Middle)Ziebach County — 20 (Lower-middle)Lake County — 31 (Lower-middle)
Where this is
Shading: Aging Vulnerability Index
Lower (0 to 18)Lower-middle (20 to 33)Middle (35 to 50)Upper-middle (51 to 75)Higher (76 to 97)
Each unit is shaded by its Aging Vulnerability Index value and grouped into equal-count bands (quantiles) against the other units shown — lighter = lower, darker = higher. It ranks position among the units in view; it does not grade places, and the ranges shift with which units are shown.

The map is bounded to this parent geography — it shows the selected unit among its own siblings only, the same depth rule the drill-down uses. Shading ranks position on the measure among the units shown; it does not grade places.
Median county: 44th percentile (among all U.S. counties).
These counties span the 0th percentile to the 97th percentile. The width of that range is the internal disparity.
Lake County is marked below — Below the median.
Well above the median11 (17%)
Above the median9 (14%)
Near the median17 (26%)
Below the median16 (24%) ◀ Lake County
Well below the median13 (20%)
Widest spread across these counties: Economic Precarity, 65+ — this theme most separates the higher- and lower-ranked counties here.

AVI ranks each county's position relative to a comparison set; it is not averaged into one number for the area, because percentiles do not average meaningfully. The distribution — median, range, and shape below — is the summary.

Lake County — by county subdivision

Median county subdivision: 17th percentile (among all U.S. county subdivisions).
These county subdivisions span the 1st percentile to the 79th percentile. The width of that range is the internal disparity.
Well above the median0 (0%)
Above the median3 (19%)
Near the median2 (13%)
Below the median2 (13%)
Well below the median9 (56%)
Widest spread across these county subdivisions: Demographic Aging Pressure — this theme most separates the higher- and lower-ranked county subdivisions here.

AVI ranks each county subdivision's position relative to a comparison set; it is not averaged into one number for the area, because percentiles do not average meaningfully. The distribution — median, range, and shape below — is the summary.
Well above the median — 11 counties (80th–100th percentile)
Day County — 97th percentile — Well above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Economic Precarity, 65+ (above), Housing & Transportation, 65+ ‡ (above) and Social Isolation (well above); below the median on Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Fall River County — 96th percentile — Well above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Housing & Transportation, 65+ ‡ (well above); near the median on Economic Precarity, 65+, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Miner County — 95th percentile — Well above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Economic Precarity, 65+ (above), Housing & Transportation, 65+ ‡ (well above) and Social Isolation (above); below the median on Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Campbell County — 93rd percentile — Well above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Health, Disability & Isolation ‡ (well above) and Social Isolation (well above); below the median on Economic Precarity, 65+ ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
McPherson County — 93rd percentile — Well above the median 5 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Economic Precarity, 65+ ‡ (above) and Social Isolation (well above); below the median on Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Jerauld County — 92nd percentile — Well above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Housing & Transportation, 65+ ‡ (well above) and Social Isolation (well above); below the median on Economic Precarity, 65+ ‡ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Hand County — 92nd percentile — Well above the median 5 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Housing & Transportation, 65+ ‡ (well above) and Social Isolation (above); below the median on Economic Precarity, 65+ ‡ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Gregory County — 88th percentile — Well above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Social Isolation (well above); near the median on Housing & Transportation, 65+ ‡; below the median on Economic Precarity, 65+ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Douglas County — 86th percentile — Well above the median 5 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Social Isolation (well above); below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Davison County — 86th percentile — Well above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Housing & Transportation, 65+ ‡ (well above) and Social Isolation (well above); near the median on Health, Disability & Isolation ‡; below the median on Economic Precarity, 65+.
‡ theme includes at least one flagged input.
Clark County — 85th percentile — Well above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Economic Precarity, 65+ ‡ (above) and Social Isolation (well above); below the median on Health, Disability & Isolation and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Above the median — 9 counties (60th–80th percentile)
Brule County — 79th percentile — Above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Health, Disability & Isolation ‡ (above) and Social Isolation (well above); near the median on Housing & Transportation, 65+ ‡; below the median on Economic Precarity, 65+.
‡ theme includes at least one flagged input.
Haakon County — 78th percentile — Above the median 6 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure ‡ (well above), Housing & Transportation, 65+ ‡ (well above) and Social Isolation ‡ (well above); below the median on Economic Precarity, 65+ ‡ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Tripp County — 76th percentile — Above the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above), Economic Precarity, 65+ (well above) and Social Isolation (well above); near the median on Housing & Transportation, 65+ ‡; below the median on Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Stanley County — 75th percentile — Above the median 6 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Health, Disability & Isolation ‡ (well above) and Social Isolation ‡ (above); below the median on Economic Precarity, 65+ ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Charles Mix County — 74th percentile — Above the median 2 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Housing & Transportation, 65+ ‡ (above); near the median on Demographic Aging Pressure, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Roberts County — 72nd percentile — Above the median 1 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above), Economic Precarity, 65+ (above) and Social Isolation (above); near the median on Health, Disability & Isolation ‡; below the median on Housing & Transportation, 65+.
‡ theme includes at least one flagged input.
Jones County — 69th percentile — Above the median 7 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure ‡ (well above), Economic Precarity, 65+ ‡ (well above) and Housing & Transportation, 65+ ‡ (above); below the median on Health, Disability & Isolation ‡ and Social Isolation ‡.
‡ theme includes at least one flagged input.
Lawrence County — 68th percentile — Above the median 2 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above) and Housing & Transportation, 65+ (well above); near the median on Economic Precarity, 65+; below the median on Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Walworth County — 65th percentile — Above the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above); near the median on Housing & Transportation, 65+ ‡; below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Near the median — 17 counties (40th–60th percentile)
Bon Homme County — 55th percentile — Near the median 2 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above) and Social Isolation (above); below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Lyman County — 55th percentile — Near the median 4 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Health, Disability & Isolation ‡ (above); near the median on Social Isolation; below the median on Demographic Aging Pressure and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Beadle County — 55th percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ ‡ (well above); near the median on Demographic Aging Pressure, Economic Precarity, 65+ and Social Isolation; below the median on Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Faulk County — 54th percentile — Near the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Social Isolation (well above); below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Codington County — 54th percentile — Near the median 2 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ (well above) and Social Isolation (above); near the median on Demographic Aging Pressure; below the median on Economic Precarity, 65+ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Sanborn County — 53rd percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ ‡ (above) and Social Isolation (well above); near the median on Demographic Aging Pressure; below the median on Economic Precarity, 65+ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Hutchinson County — 51st percentile — Near the median 2 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above); near the median on Economic Precarity, 65+ and Social Isolation; below the median on Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Perkins County — 50th percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above); near the median on Social Isolation; below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Pennington County — 50th percentile — Near the median 1 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ (well above); near the median on Demographic Aging Pressure and Health, Disability & Isolation ‡; below the median on Economic Precarity, 65+ and Social Isolation.
‡ theme includes at least one flagged input.
Kingsbury County — 48th percentile — Near the median 2 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Housing & Transportation, 65+ ‡ (well above); near the median on Social Isolation; below the median on Economic Precarity, 65+ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Turner County — 44th percentile — Near the median 2 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above); near the median on Housing & Transportation, 65+ ‡ and Social Isolation; below the median on Economic Precarity, 65+ and Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Grant County — 44th percentile — Near the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Social Isolation (above); below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Spink County — 44th percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above); near the median on Social Isolation; below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Moody County — 43rd percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (above); near the median on Demographic Aging Pressure and Economic Precarity, 65+; below the median on Housing & Transportation, 65+ ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Aurora County — 42nd percentile — Near the median 5 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above) and Social Isolation (well above); below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Edmunds County — 41st percentile — Near the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above); near the median on Social Isolation; below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Potter County — 41st percentile — Near the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Social Isolation (above); below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Below the median — 16 counties (20th–40th percentile)
Deuel County — 39th percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above) and Social Isolation (above); below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Yankton County — 38th percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (above); near the median on Demographic Aging Pressure, Housing & Transportation, 65+ ‡ and Social Isolation; below the median on Health, Disability & Isolation ‡.
‡ theme includes at least one flagged input.
Brown County — 35th percentile — Below the median View by census tract →
Driven by Housing & Transportation, 65+ (well above); near the median on Social Isolation; below the median on Demographic Aging Pressure, Economic Precarity, 65+ and Health, Disability & Isolation.
Custer County — 33rd percentile — Below the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (well above) and Social Isolation (above); below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Butte County — 33rd percentile — Below the median 4 of 12 flagged View by census tract →
Driven by Health, Disability & Isolation ‡ (above); near the median on Demographic Aging Pressure and Social Isolation; below the median on Economic Precarity, 65+ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Hyde County — 32nd percentile — Below the median 5 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure ‡ (well above); near the median on Social Isolation ‡; below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Lake County — 31st percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above); below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡, Housing & Transportation, 65+ ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Hughes County — 31st percentile — Below the median 4 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ ‡ (well above); near the median on Economic Precarity, 65+; below the median on Demographic Aging Pressure, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Buffalo County — 27th percentile — Below the median 6 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Health, Disability & Isolation ‡ (above); near the median on Housing & Transportation, 65+ ‡ and Social Isolation ‡; below the median on Demographic Aging Pressure ‡.
‡ theme includes at least one flagged input.
Corson County — 26th percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Health, Disability & Isolation ‡ (above); near the median on Housing & Transportation, 65+ ‡ and Social Isolation; below the median on Demographic Aging Pressure.
‡ theme includes at least one flagged input.
Oglala Lakota County — 26th percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Health, Disability & Isolation ‡ (well above); near the median on Housing & Transportation, 65+ ‡ and Social Isolation; below the median on Demographic Aging Pressure.
‡ theme includes at least one flagged input.
Union County — 25th percentile — Below the median 3 of 12 flagged View by census tract →
Near the median on Demographic Aging Pressure and Health, Disability & Isolation ‡; below the median on Economic Precarity, 65+, Housing & Transportation, 65+ ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Todd County — 24th percentile — Below the median 2 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Health, Disability & Isolation (above); near the median on Housing & Transportation, 65+ ‡ and Social Isolation; below the median on Demographic Aging Pressure.
‡ theme includes at least one flagged input.
McCook County — 21st percentile — Below the median 3 of 12 flagged View by census tract →
Near the median on Demographic Aging Pressure; below the median on Economic Precarity, 65+, Health, Disability & Isolation ‡, Housing & Transportation, 65+ ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Dewey County — 21st percentile — Below the median 4 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above), Health, Disability & Isolation ‡ (above) and Housing & Transportation, 65+ ‡ (above); below the median on Demographic Aging Pressure and Social Isolation.
‡ theme includes at least one flagged input.
Ziebach County — 20th percentile — Below the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Health, Disability & Isolation ‡ (well above); near the median on Social Isolation; below the median on Demographic Aging Pressure and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Well below the median — 13 counties (0th–20th percentile)
Sully County — 18th percentile — Well below the median 4 of 12 flagged View by census tract →
Near the median on Demographic Aging Pressure ‡ and Social Isolation; below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Jackson County — 16th percentile — Well below the median 1 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above); near the median on Social Isolation; below the median on Demographic Aging Pressure, Health, Disability & Isolation and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Marshall County — 15th percentile — Well below the median 4 of 12 flagged View by census tract →
Driven by Demographic Aging Pressure (above); near the median on Social Isolation; below the median on Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Bennett County — 7th percentile — Well below the median 2 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Social Isolation (above); below the median on Demographic Aging Pressure, Health, Disability & Isolation ‡ and Housing & Transportation, 65+ ‡.
‡ theme includes at least one flagged input.
Mellette County — 5th percentile — Well below the median 5 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above); below the median on Demographic Aging Pressure ‡, Health, Disability & Isolation ‡, Housing & Transportation, 65+ ‡ and Social Isolation ‡.
‡ theme includes at least one flagged input.
Minnehaha County — 5th percentile — Well below the median 1 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ (well above); below the median on Demographic Aging Pressure, Economic Precarity, 65+, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Clay County — 4th percentile — Well below the median 3 of 12 flagged View by census tract →
Driven by Economic Precarity, 65+ (well above) and Housing & Transportation, 65+ ‡ (above); below the median on Demographic Aging Pressure, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Meade County — 3rd percentile — Well below the median 3 of 12 flagged View by census tract →
Near the median on Housing & Transportation, 65+ ‡; below the median on Demographic Aging Pressure, Economic Precarity, 65+, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Brookings County — 2nd percentile — Well below the median 1 of 12 flagged View by census tract →
Driven by Housing & Transportation, 65+ (well above); near the median on Economic Precarity, 65+; below the median on Demographic Aging Pressure, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Hamlin County — 1st percentile — Well below the median 2 of 12 flagged View by census tract →
Near the median on Housing & Transportation, 65+ ‡; below the median on Demographic Aging Pressure, Economic Precarity, 65+, Health, Disability & Isolation ‡ and Social Isolation.
‡ theme includes at least one flagged input.
Harding County — 1st percentile — Well below the median 7 of 12 flagged View by census tract →
Below the median on Demographic Aging Pressure ‡, Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡, Housing & Transportation, 65+ ‡ and Social Isolation ‡.
‡ theme includes at least one flagged input.
Lincoln County — 1st percentile — Well below the median 1 of 12 flagged View by census tract →
Near the median on Housing & Transportation, 65+ ‡; below the median on Demographic Aging Pressure, Economic Precarity, 65+, Health, Disability & Isolation and Social Isolation.
‡ theme includes at least one flagged input.
Hanson County — 0th percentile — Well below the median 5 of 12 flagged View by census tract →
Below the median on Demographic Aging Pressure, Economic Precarity, 65+ ‡, Health, Disability & Isolation ‡, Housing & Transportation, 65+ ‡ and Social Isolation.
‡ theme includes at least one flagged input.
AVI = a candidate Aging Vulnerability Index, computed by this platform from American Community Survey 2020–2024 5-year estimates, following the same method shape (percentile rank -> theme sum -> re-rank -> overall) as the CDC/ATSDR SVI this platform also recomputes — but AVI itself has no published ground truth to validate against. It is a first-cut, directional design. Percentiles rank each county against all U.S. counties.
Several of AVI's 12 input signals carry a documented high margin of error at this grain (most notably lack of health insurance, 65+) and are kept in the index with a flag rather than dropped, to preserve variable coverage. A county's flag count (shown per-county above) is a direct measure of how much its rank should be read as directional rather than precise.

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