The ongoing federal government shutdown could start affecting the US housing market soon.

Federal workers not receiving pay owe $249 million in mortgage payments and $189 million in rent payments this month, according to Zillow.

Some federal housing programs, such as Federal Housing Administration loans, Veterans Affairs loans, and US Department of Agriculture loans, are experiencing delays.

Additionally, the Department of Housing and Urban Development cannot pay rental assistance to landlords who provide roughly 100,000 low-income Americans with affordable housing.

The ongoing government shutdown looks like it may cause a mess for the US housing market.

As the shutdown enters a record-tying 21st day, a number of worries are piling up, including looming mortgage payments for federal workers and missing rent assistance from the Department of Housing and Urban Development (HUD).

The problems have left workers worried about making ends meet, potential buyers frozen out of loans, and affordable-housing experts concerned about evictions.

Missing paychecks mean missed payments

A demonstrator on January 10, 2019. Carlos Barria/Reuters

The most direct effect of the government shutdown on the housing market is the increasing possibility that the 800,000 federal workers who are not receiving paychecks during the shutdown are going to face a mortgage or rent bill without any income to pay it.

According to online real-estate-database firm Zillow, federal workers who are not receiving paychecks have $249 million in mortgage payments and $189 million in rent payments due this month.

Read more: From airport lines to food inspections, here are all the ways the government shutdown is impacting the lives of average Americans

While the Office of Personnel Management released guidance for federal employees who may experience problems, many employees worried that the suggestions — which include writing letters to landlords asking for a delay — are woefully inadequate.

"No payments means no gas for our cars, no money for our prescriptions, our groceries, our rents and our mortgages," Steve Ching, an electrician who contracts for NASA, told the Washington Post. "We're all wondering how long our families will be able to hold out."

Services for homebuyers are experiencing some problems

TSA agents are working without pay, and lines are getting longer at airports as many have been calling in sick or even quitting. AP Photo/Manuel Balce Ceneta

In addition to the looming payments for federal workers, the federal government has also stopped activities such as loan programs and income checks that people need to buy homes.

While Federal Housing Administration (FHA) loans are going out during the shutdown, certain reverse mortgages and permanent improvement loans are not being issues. Additionally due to restricted workflows, new applicants may experience some delays.

Veteran's Affairs (VA) loans will go out during the shutdown since the VA is funded for the full year.

Additionally, the US Department of Agriculture (USDA), which provides loans for people buying homes in rural areas, is not processing those requests.

The IRS is also working through a backlog of income verifications that are needed for some borrowers because the process was paused when the shutdown went into effect, so some buyers may experience delays.

Read more: The government shutdown is in a record-tying 21st day and the fight between Trump and Democrats is only getting uglier. Here's everything you missed.

These pauses are causing problems for some people trying to buy a new home, according to a survey by the National Association of Realtors released on Tuesday.

Three-quarters of Realtors surveyed reported no clients having issues because of the shutdown. But 22% said a client or potential client was having trouble, with reasons for disruptions including:

25% said "the buyer decided not to buy due to general economic uncertainty, though they were not a federal government employee"

17% had a client who was unable to get a USDA rural home loan processed because of the shutdown

13% had a delay because of IRS income verification problems

9% had a delay because of the FHA pausing loans

9% said they had a client who decided not to buy because they were a federal employee

6% had a seller who could not sell because their move was impacted by the shutdown

3% had a client who was rejected for a loan because they were on furlough

3% had a buyer who decided not to buy because they were on furlough

Affordable housing problems

President Donald Trump visited the US-Mexico border on Thursday. Leah Millis/Reuters

The housing problems are also threatening to hit some of the most vulnerable Americans, with HUD experiencing a funding shortfall.

Contracts with 1,150 landlords who offer subsidized units for low-income Americans have expired during the government shutdown and another 500 contracts will expire in January, according to the Washington Post. This means those landlords will not receive the federal assistance to offset the lower rent costs, and as many as 100,000 low-income tenants could face eviction.

HUD has sent letters to those landlords who are no longer under contract asking for extensions and a HUD spokesperson told the Post that no one has ever been evicted because of a shutdown.

But the funding lapse is poised to set the record for longest shutdown in the modern budgeting era on Saturday — and the unprecedented length could mean unprecedented effects.