Roughly 9.5 million U.S. households are behind on their rent, according to the latest census data— yet nearly half the money from a COVID rent relief program first approved by Congress over a year ago remains unspent.

Still, the pace of the distribution has been picking up. The U.S. Treasury says November was the biggest month yet for the “renter stimulus checks," with about 665,000 renters and landlords receiving $2.9 billion in payments, and some states are running out of the aid, according to a report.

The government says the money has helped evictions stay below the levels seen before the pandemic.

Up to tens of billions still available

The last two COVID stimulus packages passed by Congress — in December 2020 and March 2021 — set aside a total of $46.6 billion to help renters pay overdue rent and utility costs.

So far, between $25 billion and $30 billion of the aid has been paid out, the Treasury revealed on Friday. That means as much as $21.5 billion, or over 46%, of the funds are still available.

The cash is being provided by Washington, but it's being distributed through hundreds of agencies and organizations at the state and local levels. And many of them were slow to get moving, leading to holdups last year in many parts of the U.S.

With aid spread across many different housing authorities, each with their own resource and capacity constraints, renters in different places did not receive the same levels of service or responsiveness.

Now that the program is working better, officials say it has contributed to relatively low eviction numbers in the months since a national eviction moratorium ended in August.

Some states run out of rental assistance

The stimulus aid available to renters can be sizable. In Illinois, eligible tenants and landlords have been able to apply for one-time grants of up to $25,000 to pay off a maximum 15 months of rent missed between June 2020 and August 2021.

The program in Texas has covered unpaid rent and utilities going as far back as March 13, 2020, and paid for up to two months of future rent and utilities. The relief for Texas renters capped out at $4,600 per month.

But the Lone Star State and a few others have already exhausted all of the federal money they were allocated through the program, according to The New York Times. That's contributing to the anxiety among renters.

More than a quarter of U.S. renters say they're not at all confident or only slightly confident that they'll be able to make their next rent payment, according to data from a census survey taken during the first half of December.