This week Congress will discuss funding for housing vouchers, which help very low-income families, the elderly and the disabled afford housing in the private market. In Maine, the need for Section 8 vouchers has outpaced availability, pointing to a larger systemic problem: The state and nation lack enough quality, affordable housing to match people’s income levels.

Typically, about 12,000 people receive vouchers each year in Maine, and an additional 12,000 remain on waitlists. Some housing authorities have closed their waitlists, however, meaning the need is greater.

On Wednesday, U.S. Housing and Urban Development Secretary Shaun Donovan is scheduled to discuss proposed budget estimates for fiscal year 2015 before the Subcommittee on Transportation and Housing and Urban Development, of which Sen. Susan Collins, R-Maine, is ranking member.

Maine residents should be watching to make sure the state’s base level of housing vouchers will be restored. About 500 of the state’s 12,000 vouchers were eliminated due to federal across-the-board spending cuts known as sequestration. Though the fiscal year 2014 federal budget restored 250 vouchers, the state is still short 250.

Though restoring them to pre-sequestration levels is a small step, it would help make sure homelessness in Maine doesn’t get worse.

Roughly 30,000 Maine households paid more than half their monthly income for housing costs in 2013, representing a 55 percent increase since 2007, according to the Center on Budget and Policy Priorities. In Maine, 94 percent of vouchers are held by the elderly, adults with children or disabled adults.

While restoring the number of vouchers is important, it should not distract from the larger issue at hand: the limited housing options for those with very low incomes. In 2009, the the MIT Center for Real Estate reviewed existing housing stock in Maine and compared rents with people’s incomes. It provided a number of scenarios.

For example, is it possible for an elderly woman living alone with an income of $13,230 to pay no more than 30 percent of that income ($331 or less per month) on rent in the greater Portland area? It is not. Even when spending 50 percent of her income on rent, Biddeford is the only municipality in which she could reside, as long as there were available rental units.

What about a single mother with two teenage children earning $28,350 per year? There are three-bedroom apartments available in greater Portland, but she would have a hard time finding one at a rate she could afford — $700 per month. Her cheapest options would be to spend 34 percent of her income on housing to afford the median rent in Biddeford or 40 percent of her income on rent in Portland.

There are ways for the country to incentivize the construction and rehabilitation of rental homes that are affordable for households with low incomes. That is what the National Housing Trust Fund — created by Congress and authorized by President George W. Bush in 2008 — would do, if it were funded by Fannie Mae and Freddie Mac as federal law intended. The fund was never financed because the mortgage crisis prompted the two companies to be taken into conservatorship. They have now recovered and should contribute to the fund, which would allocate grant funding for states to build or fix up rental homes that low-income individuals could afford.

While many different factors make people more vulnerable to homelessness — such as mental or physical health, substance abuse and poverty — one of the biggest drivers is the availability of affordable rental housing. Units are generally deemed affordable when people pay no more than 30 percent of their income on rent.

Collins and Sen. Angus King, I-Maine, along with many others, are advocating for changes to increase the availability of safe, decent, affordable housing. And HUD has agreed with them on the need for reform. Now, Congress needs to act.