Affordable housing is housing where the rent or mortgage stays below 30 percent of a household's gross monthly income

That 30 percent threshold is the standard used by housing agencies, lenders, and government programs across the United States. If your household brings in $3,000 a month, affordable housing for you costs $900 or less. If you earn $5,000 a month, it costs $1,500 or less. The math is straightforward, but the reason it matters is not: when housing takes more than 30 percent of your income, you have less money left for food, medicine, childcare, and transportation.

Affordable housing itself is not a single program or a single type of building. It is a category that includes public housing, Section 8 vouchers, tax-credit apartments, deed-restricted units in mixed-income buildings, and privately owned rentals where the rent happens to fall below that threshold. Some affordable units are managed by nonprofits. Some are owned by for-profit landlords. Some are brand new. Some are decades old. What they share is that price point.

The shortage of affordable housing is not about the number of apartments that exist. It is about the gap between how many units rent below 30 percent of income and how many households need them. In most U.S. cities, that gap is wide. More households need affordable units than units exist, which is why waiting lists are long and competition is fierce.

Key Takeaways

  • Affordable housing means rent or a mortgage payment that does not exceed 30 percent of your household's gross monthly income.
  • Affordable units can be public housing, Section 8 apartments, tax-credit buildings, or private rentals—the category describes the price, not the owner or the building type.
  • The shortage of affordable housing means more households need low-cost units than units exist in most cities, which creates long waiting lists.
  • Income limits for affordable housing programs vary by location and household size, and they change yearly based on area median income.
  • Affordable housing is not the same as subsidized housing—some affordable units receive government money, and some do not.

How the 30 percent rule works in practice

The 30 percent standard comes from federal housing policy and is used by the Department of Housing and Urban Development (HUD), lenders, and housing authorities nationwide. It is the measure they use to decide whether a household is cost-burdened—meaning housing takes up too much of their money.

To calculate it, take your household's gross monthly income (before taxes) and multiply by 0.30. That number is the maximum affordable rent. If you earn $2,400 a month gross, 30 percent is $720. If you earn $4,000 a month gross, 30 percent is $1,200. Some households spend far more than 30 percent—40, 50, or even 60 percent of income on rent—which is why they are considered severely cost-burdened.

The 30 percent rule applies to both renters and homeowners. For renters, it is the monthly rent. For homeowners, it is the monthly mortgage payment plus property taxes, insurance, and homeowners association fees if they explore. The rule is the same; the numbers change based on what you earn.

Affordable housing versus subsidized housing

These terms are not the same, and the difference matters. Affordable housing is any housing where the rent or payment falls below 30 percent of income. Subsidized housing is housing where the government or a nonprofit pays part of the cost on your behalf.

A unit can be affordable without being subsidized. For example, a landlord might rent a two-bedroom apartment for $800 a month in a low-cost area. If you earn $3,000 a month, that rent is affordable to you (it is 27 percent of your income), but the landlord receives no government subsidy. You pay the full $800 yourself.

A unit can also be subsidized without being affordable to everyone. A Section 8 voucher subsidizes part of your rent, but the program has income limits. If you earn too much, you cannot use the voucher, even though the subsidy would make the unit affordable to you. Subsidized programs target specific income ranges; affordable housing is straightforward a price point.

Income limits and area median income

Most affordable housing programs set income limits based on the area median income (AMI) for your city or county. AMI is the middle point—half of households earn more, half earn less. HUD calculates AMI for every metro area and updates it yearly.

A program might say it serves households at 60 percent of AMI or 80 percent of AMI. If your area's AMI is $75,000 for a family of four, then 60 percent AMI is $45,000 and 80 percent AMI is $60,000. Income limits change every year because AMI changes. A household that was within the limit last year might be over it this year, or vice versa.

Income limits also vary by household size. A program's limit for a single person is lower than its limit for a family of four. When you look at a specific affordable housing program, you need to know both the AMI percentage it serves and your household size to know whether you fall within the limit.

Types of affordable housing

Public housing is owned and operated by local housing authorities. Units are typically older, and rent is set at 30 percent of your income. Waiting lists are long in most cities.

Section 8 vouchers let you rent from a private landlord and pay 30 percent of your income toward rent. The voucher covers the rest, up to a limit set by the program. Waiting lists are often closed.

Low-income housing tax credits are federal tax breaks given to developers who build or rehab apartments for low-income households. These units are often newer or recently renovated and are mixed into regular apartment buildings. Income limits explore, but rent is typically lower than market rate.

Deed-restricted units are apartments in market-rate buildings where the owner has agreed to keep some units affordable for a set number of years in exchange for tax breaks or financing help. They look and function like regular apartments but cost less.

Naturally affordable housing is privately owned housing that happens to rent below 30 percent of income without any government subsidy or restriction. This is becoming rarer as rents rise in most cities.

Why affordable housing is hard to find

The shortage exists because construction costs, land prices, and property taxes have risen faster than wages. A developer building new apartments needs to charge enough rent to cover these costs and make a profit. In most cities, that rent is above what low-income households can afford.

Affordable housing programs help close the gap by subsidizing rent, providing tax breaks to developers, or using public money to buy and operate buildings. But the amount of money available is far smaller than the need. In most cities, waiting lists for public housing and Section 8 vouchers are years long, and some are closed to new applicants.

Naturally affordable housing—units that rent cheaply without any subsidy—is disappearing. When a lease ends or a building changes hands, the new owner typically raises the rent to market rate. This is why most affordable housing today depends on some form of government support or nonprofit ownership to keep rents down.

How affordable housing income limits are set

HUD publishes income limits for every county and metro area each year, usually in April. These limits are based on area median income and are used by most affordable housing programs, including Section 8, public housing, and tax-credit apartments.

The limits vary widely by location. A family of four earning $60,000 a year might be over the income limit in San Francisco but well within it in rural Mississippi. The same household's affordability also changes: $60,000 goes much further in a low-cost area than in a high-cost one.

When you look at a specific affordable housing program, check the current year's income limits for your county and household size. Do not use last year's limits or limits from a different county. Programs update their limits yearly, and using old numbers can lead you to explore for something you do not may have access to for.

Frequently Asked Questions

Is affordable housing the same as low-income housing?

Not exactly. Low-income housing is housing for people with low incomes, and it usually means housing with income limits attached. Affordable housing is any housing where the rent or payment is 30 percent or less of income. A household earning $100,000 a year might find a unit affordable, but it would not be considered low-income housing because the household's income is too high.

Can I live in affordable housing if I earn too much?

It depends on the program. Some affordable housing has no income limits—you can live there if you can afford the rent, regardless of how much you earn. Other programs, especially subsidized ones like Section 8 and public housing, have strict income limits. If you earn above the limit, you cannot use the program, even if the rent would be affordable to you.

Does affordable housing mean the building looks run-down?

No. Some affordable units are in older buildings, but many are new or recently renovated, especially tax-credit apartments and deed-restricted units in mixed-income buildings. The affordability is about the price, not the condition. You may find brand-new affordable apartments next to market-rate units in the same building.

What happens to affordable housing when the subsidy ends?

Most subsidies or deed restrictions last 15 to 40 years. When they end, the owner can raise the rent to market rate. Some nonprofits buy buildings before the subsidy ends to keep them affordable permanently, but this is not may provide. If you live in an affordable unit with a time limit, plan ahead for when that protection expires.

How do I find affordable housing in my area?

Contact your local housing authority to ask about public housing and Section 8 waiting lists. Call 211 or visit 211.org to find affordable housing programs and nonprofits in your area. Many cities have online searchable lists of affordable apartments. Your city or county housing department can also point you to resources specific to your location.