Massachusetts’ public housing is deteriorating. The cost to fix it could be billions.

Housing authorities are urging Beacon Hill to play catchup on repairs to crumbling state-funded public housing stock.

Decades ago, Massachusetts went above and beyond when it came to housing its poorest residents, building tens of thousands of smaller public housing apartments on its own dime as a supplement to the larger complexes that were funded by the federal government.

It’s been downhill ever since. After that initial infusion of funding that financed the construction, the state has done little to maintain its 43,000 units of public housing, leaving hundreds of properties in a chronic state of disrepair, with even everyday maintenance such as replacing broken floor tiles or rodent control falling to the wayside.

The 70,000 people who call these places home are paying the price: children with elevated levels of lead in their blood, one resident who fell on a neglected staircase and broke her arm, a rodent problem so bad a family’s young children sleep in a top bunk because rats scurry across the floor at night.

Shayok Chakraborty of the Greater Boston Interfaith Organization stood on the stairs where paint is peeling from the wall at the Brookline Housing Authority apartment complex.Craig F. Walker/Globe Staff

“It is a blessing to have a home for my family, but the conditions — the mice and the stairs — can be challenging to endure,” said Pratika Pradhan, who lives in a state-funded building in Brookline with her two young children.

Conditions have become so deplorable that housing authority leaders and advocates are campaigning the Legislature and Governor Maura Healey for a whopping $9 billion in the new state budget for the next fiscal year and in a bond bill for housing to bring the units into acceptable condition. So far in the annual budgeting season, the state Senate has proposed $107 million for yearly operating costs of the state’s more than 240 local housing authorities, roughly $70 million short of what public housing leaders say is needed.

One advocate called the $107 million “spare change,” compared with the need.

“When you walk through the units and talk to the residents who live here, the conditions are shocking,” Alaa Eldamaty, an organizer with the Greater Boston Interfaith Organization’s housing justice campaign, said during a tour of Brookline’s public housing. “The fact that it’s been allowed to deteriorate to this point, and that our elected officials still haven’t significantly increased the funding for public housing is a massive failure of political will.”

Carlos Tamayo showed the condition of the tile floor in his kitchen. (Craig F. Walker/Globe Staff)

A deteriorating wall and rusted heating system in his home. (Craig F. Walker/Globe Staff)

Public housing is underfunded everywhere, but the shortfall in Massachusetts is unique in part because the state, from the 1940s through the ‘70s, was one of just four to construct its own portfolio of public housing.

That approach meant that more public housing was built in Massachusetts than in many other states — roughly 43,000 state-funded units, in addition to 33,000 US-funded units — but it also created a unique, and expensive, obligation on the state to maintain those properties.

In the early years, rents from tenants and state subsidies were enough to keep the buildings in decent condition. But over time, as the buildings got older, maintenance costs stacked up, and the need for bigger repairs overwhelmed the modest amounts allocated to keep the units running.

“My job has become deciding what is the most urgent problem and hopefully fixing that,” said David Hedison, executive director of the Chelmsford Housing Authority. “We don’t have money for sidewalks or stairs or those sorts of things. And it’s our residents, our very low-income or senior or disabled residents, who are suffering because of it.”

Alaa Eldamaty of the Greater Boston Interfaith Organization crossed the street outside the Brookline Housing Authority Trustman Apartments complex.Craig F. Walker/Globe Staff

The concerns are hardly new. In 2001, the Citizens’ Housing and Planning Association projected the state would need nearly $1.5 billion over a decade to “stabilize and reinvigorate” its public housing stock. That additional amount never came, and, in the meantime, the disrepair has only accelerated.

There is even less money for major capital projects, which are desperately needed across the state to repair decades-old sewer and electrical systems, or to replace buildings altogether. The Massachusetts Department of Housing and Community Development, or DHCD, estimates there is roughly $3.7 billion worth of replacements to roofs and bathrooms and other costly systems. Officials at local housing authorities say the true cost, after accounting for installation and bringing buildings up to code, is more than double that. Yet, the state currently has allocated just $55 million from the current housing bond bill for capital spending this year, with the funds split among the local housing authorities

That forces officials such as Hedison to spend what little money they get on only the most urgent repairs.

His housing authority in Chelmsford has just $260,000 this year to cover what DHCD estimates is $16 million worth of major deficiencies within his buildings. That means the sagging wooden porches in a senior housing complex will stay, for now. So will holes in the sidewalks that residents have tripped over.

“When your buildings are this old, the job becomes putting out fire after fire,” said Hedison. “And when we have to keep spending money on emergency repairs, we don’t have anything left to tackle the big replacements we need to do. Not even close.”

At one 50-unit building in Chelmsford, tenants are being temporarily moved out because the property is overrun with asbestos and has a failing electrical system. DHCD deemed the building to be in poor enough condition to qualify for funding to renovate it. But that extra infusion of cash for repairs is exceedingly rare, and many state-funded properties in the same or worse shape don’t get it.

And it’s not just small towns. Even larger, wealthier communities such as Brookline face the same difficult choices. The Brookline Housing Authority this year received around $475,000 in capital funds from the state, but has $31 million worth of failing infrastructure.

On a recent tour of Brookline’s state-funded public housing units, that shortfall was obvious. Some residents use dozens of rodent and insect traps. Staircases were deteriorating. Paint peeled from the walls in huge patches.

And there’s not much Michael Alperin, executive director of Brookline’s housing authority, can do about it. Some of these buildings were built as early as the 1940s, and there’s little money for repairs.

“I got into this field because I want to improve people’s lives,” said Alperin. “So it’s painful that this job is about making sacrifices, even when we know how significantly the conditions in our buildings need to improve.”

And while federally funded housing projects were often built around the same time, there’s more money to redevelop them. The difference can be stark.

:A couple walks into the O'Shea House in Brookline. This building received federal funds for renovations. Craig F. Walker/Globe Staff

At the O’Shea House, a 100-unit high-rise near Coolidge Corner that is federally funded, new elevators take residents between floors and each apartment has a modern-looking finish. The building is one of five public housing properties in Brookline the housing authority has redeveloped through the federal government’s Rental Assistance Demonstration program, which allows housing authorities to convert a building’s public housing subsidies to Section 8 vouchers and utilize loans and grants to finance big renovations.

To be sure, federal public housing is hugely underfunded as well. The Department of Housing and Urban Development estimates that, nationwide, there is a $26 billion backlog of deferred maintenance on those properties, though the figure is likely much higher. But HUD also has more well-funded redevelopment programs.

A few housing authorities in Massachusetts have managed one-off redevelopments of state-funded public housing by partnering with private developers who add market-rate units to the property. In Chelsea, for example, the housing authority financed the redevelopment of its aging, 96-unit Innes Apartments by adding 196 market-rate units onto the property.

Alaa Eldamaty (left) and Shayok Chakraborty of the Greater Boston Interfaith Organization admired an apartment during a tour of the O'Shea House in Brookline. This building received federal funds for renovations. Craig F. Walker/Globe Staff

But generally, local housing authority leaders said, those opportunities with state-funded buildings are few and far between.

A DHCD spokesperson said in a statement that the Chelsea development is a replicable model.

“The Administration is eager to partner with more local housing authorities to leverage state and federal tax credits, capital investments, and private funding to redevelop public housing and increase housing opportunities throughout the Commonwealth,” the spokesperson said.

Still, advocates say that without an influx of funding the state is at risk of losing units or buildings. Take Chelmsford’s 50-unit building as the tip of the iceberg.

“We can’t hold buildings together with duct tape,” said Hedison. “We need funding, or we’re going to lose a lot of important homes.”