By Len Fishman

Low-income elder Americans face a housing crisis today. We don’t have nearly enough decent, affordable housing for them, and our country’s aging population is adding waves of new seniors to the waiting lists every day.

States and the federal government generally do not build new affordable housing directly. Instead, they maintain a market-based system that allows private firms and nonprofits (many of them faith-based) to partner with government to build and preserve housing for low-income elders and the working poor.

For decades, this public-private partnership has been the main engine driving new construction and preservation of subsidized senior housing. With the passage of tax legislation in both houses, Congress now faces a stark choice.

The House tax bill would eliminate private activity bonds and accompanying tax credits—one of the last forms of government support making private investment in affordable housing for seniors possible. The Senate bill would leave the bonds and tax credits largely intact. It’s essential that a final bill preserves these critical tools to help us address the dire housing problem facing many of our most vulnerable citizens.

Part of the senior housing challenge is simple demographics. Roughly 10,000 Baby Boomers turn 65 every day in the United States, and that pace will continue unabated for the next 12 years. Not surprisingly, many of them live on limited financial resources.

The housing experience of low-income seniors this decade is a warning of more serious trouble ahead. About 3.9 million U.S. households aged 62 and over qualified for subsidized housing (meaning their incomes were at or below 50 percent of area median) but only about a third actually received rental assistance in 2011, according to the Harvard Joint Center for Housing Studies.

As commissioner of health and senior services for the state of New Jersey in the 1990s, I was aware of the growing gap then between the demand for subsidized housing for low-income seniors and the available supply. Later, the data turned into real people, whom I came to know, in my job as CEO of Hebrew SeniorLife, New England’s largest non-profit provider of long-term services and supports (LTSS).

HSL owns and operates housing facilities for low-income seniors in the Massachusetts municipalities of Revere, Randolph and Brookline. Waiting lists for our facilities were long; the typical wait was six to eight years, and there were approximately eight applicants for each apartment.

For those fortunate enough to get in, the event was often life-changing. Seniors who had been spending as much as 50 percent or more of their income on rent now had their rent capped at 30 percent of income, leaving them more money to pay for food, health care and the other necessities of life. Their new accommodations were safe and well-maintained, with social workers right in their buildings to help them navigate the maze of health care and social service programs. They had neighbors and staff to look out for them, and the socialization vital to health and happiness.

I came to realize that, for low-income seniors, the most important social determinant of health is their home, because so much else depends on that—access to health care services, nutritional food, transportation, economic security, and social connection. Almost all our residents had multiple health conditions—many had five or more—and these most vulnerable elders were more likely to get the care they needed and to age-in-place successfully, thanks to the supportive environment of their subsidized housing.

The most important remaining government program assisting the construction and preservation of affordable housing like that involves the tax-exempt private activity bonds and an accompanying 4 percent low-income housing tax credit.

Nationally, more than half of all low-income housing tax credit transactions were financed using 4 percent credits in 2016, according to LeadingAge, a leading national organization representing non-profit providers of LTSS for elders. That vital resource is put at risk by the House bill.

Many states have increasingly used the 4 percent credit as a staple to preserve and create low-income senior housing. MassHousing, a quasi-public agency in Massachusetts, commonly issues private activity bonds with 4 percent tax credits to attract private investment in affordable housing projects.

Elders occupy about 40 percent of the 14,315 affordable housing units built or preserved with MassHousing financing since 2012. In recent years, MassHousing has helped raise funding for projects to renovate or improve Quincy Tower in Boston’s Chinatown, the Louis Barrett Residents in Lynn and the Binnall House in Gardner. It helped finance new construction of the Cohen Residence in Brookline. Combined, those projects alone provide more than 500 units of senior housing.

Another project is underway right now at the Gitta & Saul Kurlat House in Brighton, which has been home to about 300 low-income seniors for three decades. The building has served its residents well but, after 30 years, was in need of investment.

Bond financing and accompanying tax credits have paid for basic work to the roof, as well as the heating and electrical systems. Interiors were updated and, in some cases, reconfigured to accommodate the turning radius of wheelchairs. New windows are easier to operate for seniors. Common areas, including elevators, were improved. The project, which began in the summer of 2016, will be completed next year.

But the mechanism used by MassHousing to do this work would not be available without the private activity bonds that the House bill eliminates. In fact, MassHousing estimates that the loss of the 4 percent credit and other elements of the House bill would eliminate four of every five affordable units built or preserved in the state each year.

Not long ago, Congress was on the verge of repealing the Affordable Care Act. As much as Congressional Republicans despise Obamacare, most of them recognized that if they repealed it, they would have to replace it with something. By contrast, affordable housing for low-income seniors is not controversial, and yet the House tax bill would eliminate the main mechanism used to create and preserve it—and would replace it with . . . nothing.

We are already woefully short of the subsidized housing units needed by low-income seniors today. Demand will likely grow by another 2.6 million units by the year 2030. We should be adding new programs to close this gap, not eliminating the main mechanism used to keep the supply growing. Unfortunately, new programs are not on the table. Instead, the conference committee must reconcile the Senate’s approach, which comes closest to maintaining the status quo, inadequate as it is, and the House’s proposal to severely curtail the growth of affordable housing for low-income elders. We should, first, do no harm and then work for legislation that would secure the future of vulnerable elders in need of the most basic of needs: decent, affordable housing.

Len Fishman is director the Gerontology Institute at UMass Boston’s McCormack Graduate School.