For each ZIP code, the map shows whether the annual cost of owning a typical 3-bedroom or 4-bedroom home exceeds 31% of the area's median family income for nonelderly married-couple households. It assumes a 6% 30-year fixed-rate mortgage, a 10% down payment and other assumptions from the Atlanta Fed's Home Ownership Affordability Monitor. The switch at the top of the legend changes the home size.
31% is FHA's standard guideline for the maximum housing payment as a share of income, also known as the front-end ratio. Gray means the ZIP code is inside a covered CBSA, but data isn't available. This is usually because there's no Zillow home value for it.
For California and Florida, property taxes use new-buyer effective rates instead, as described below.
Home values
Home values are the Zillow Home Value Index (ZHVI) for 3-bedroom and 4-bedroom homes, March 2026. This is the mid-tier series (homes between the 35th and 65th percentiles of value), smoothed and seasonally adjusted. See the ZHVI methodology and Zillow data. Both home sizes use the same cost assumptions and income.
Income
Metro area median family income for married-couple families where neither spouse is elderly (both aged 18–64), from the 2024 American Community Survey 5-year sample, using IPUMS USA microdata. Income is total family income in 2024 dollars, for metro areas approximated from Public Use Microdata Areas (PUMAs).
Incomes are updated to March 2026 using FRED's Average Hourly Earnings of Production and Nonsupervisory Employees, Total Private (AHETPI): the 2024 income is multiplied by the March 2026 value divided by the 2024 annual average. (That's an increase of about 6.6% across the board.)
Housing costs
Following the Atlanta Fed's Home Ownership Affordability Monitor (HOAM; see its explainer), costs add up:
- principal and interest on a 30-year fixed-rate loan for 90% of the ZHVI, assuming 10% down,
- property tax at the county's rate, as described below,
- homeowners insurance at the CBSA's effective rate, based on HOAM's March 2026 monthly insurance amount,
- private mortgage insurance (PMI) at 0.558% of the loan per year.
The down payment, closing costs, maintenance, utilities and HOA fees are excluded.
Property tax
The county's effective rate from the Tax Foundation's Property Taxes by State and County, 2026 (based on 2024 5-year ACS estimates), multiplied by each ZIP code's ZHVI. California and Florida reassess homes at sale, so their property taxes are adjusted:
- California: the county's average tax rate (the 1% Prop 13 rate plus voter-approved debt) from the Board of Equalization's 2024-25 Annual Report × (ZHVI − $7,000 homeowners' exemption).
- Florida: each county's school and non-school tax rates, calculated as taxes levied ÷ taxable value from the Department of Revenue's 2025 County Property Tax Overviews. Tax = school mills/1000 × (0.85 × ZHVI − $25,000) + non-school mills/1000 × (0.85 × ZHVI − $50,000). The 0.85 reflects Florida's assessment at sale price less 15% for costs of sale; the dollar amounts are homestead exemptions.
County matching
ZIP codes are matched to counties using GeoNames postal-code counties, with Connecticut planning regions via a crosswalk. For California and Florida, they use HUD's USPS ZIP–county crosswalk (June 2026); each ZIP is assigned to the county with most of its residential addresses.
Mortgage rate
6% is the average 30-year FHA rate for March 2026, rounded to the nearest 0.1%, based on the Optimal Blue 30-Year Fixed Rate FHA Mortgage Index for that month.
Caveats
- Property tax rates are county averages, and insurance rates are CBSA averages. Actual rates vary by town, school district and individual property.
- Special assessments aren't included, such as California's Mello-Roos and parcel taxes or Florida's flat fees for fire, trash and stormwater.
- HOA fees aren't included.
- The ZHVI is an estimate of a typical home value, not of recent sale prices in the area.
- ZIP codes are assigned to CBSAs using HUD's December 2024 USPS ZIP–CBSA crosswalk. Each ZIP code goes to the CBSA that holds most of its residential addresses. Connecticut ZIPs were assigned separately, using the crosswalk provided in the cost file.
Data sources
- ZIP boundaries: U.S. Census Bureau, 2020 cartographic ZCTAs (cb_2020_us_zcta520_500k)
- CBSA boundaries: U.S. Census Bureau, 2025 cartographic CBSAs (cb_2025_us_cbsa_500k)
- Basemap: OpenFreeMap (Positron style) © OpenMapTiles © OpenStreetMap contributors, rendered with MapLibre GL JS
- Replication data: every ZIP code's inputs and results, plus CBSA incomes, in the replication folder on GitHub. Tax Foundation rates are licensed CC BY-NC 4.0; home values are Zillow Group data.
- Income: Steven Ruggles, Sarah Flood, Matthew Sobek, Daniel Backman, Grace Cooper, Julia A. Rivera Drew, Stephanie Richards, Renae Rodgers, Jonathan Schroeder, and Kari C.W. Williams. IPUMS USA: Version 16.0 [dataset]. Minneapolis, MN: IPUMS, 2025. https://doi.org/10.18128/D010.V16.0
Updates
- October 30, 2026: added the 4-bedroom view.
- October 29, 2026: property tax changed from CBSA-wide HOAM rates to county rates (Tax Foundation), with new-buyer estimates for California and Florida.