NASA staff and contractors working on Artemis, the moon exploration program that contracts with Elon Musk's SpaceX and Jeff Bezos' Blue Origin, will stay on the job during the shutdown, according to internal memos obtained by CNBC.

Those employees will not be paid "for the duration of the shutdown furlough," but they should record their time and expect to be paid after the government reopens, NASA Chief Human Capital Officer Kelly Elliott wrote in an email to staffers on Wednesday.

NASA's acting CFO Stephen Shinn said in a separate shutdown memo issued Monday that the space agency would support "planned operations" of the International Space Station and any satellite mission that "is in the operations phase," in addition to "Artemis operations during any funding lapse."

The plan said NASA expected to furlough around 15,000 people and require around 3,000 staffers to keep working, part time or full time, during the shutdown.

— Lora Kolodny

A shutdown-induced delay in the release of key economic data could impact the announcement of the Social Security cost-of-living adjustment for 2026, according to the Department of Labor.

New consumer price index data is scheduled to be released on Oct. 15 by the Bureau of Labor Statistics, a division of the Department of Labor. The Social Security Administration is expected to announce the 2026 COLA this month based on that data.

But BLS is suspending operations during the shutdown, the Labor Department said in a contingency plan issued Friday.

More than 74 million Social Security beneficiaries may see an increase in their monthly payments next year, based on the annual inflation adjustment.

Estimates released in September indicated that beneficiaries may see a 2.7% to 2.8% increase to their monthly checks in 2026, which would push the average retirement benefit up by about $54 per month.

— Lorie Konish

The government shutdown is likely to drag on for at least three days, with the Senate set to be out of session tomorrow in observance of Yom Kippur.

Senators are not expected to vote again until Friday, more than two days after the shutdown began, NBC News reported.

Lawmakers are still at an impasse over a deal to fund the government.

— Erin Doherty

Homebuyers who need specific mortgages through the Federal Housing Administration, Veteran Affairs, and U.S. Department of Agriculture loans could experience delays during the shutdown, said Ted Rossman, senior industry analyst at Bankrate.

However, buyers applying for government-backed mortgages via Fannie Mae and Freddie Mac should not be affected by the shutdown, Rossman said.

Those who need flood insurance through the National Flood Insurance Program can also "expect delays in closing," said Melissa Cohn, regional vice president of William Raveis Mortgage. 

The NFIP's authority to issue new policies has lapsed, complicating about 1,400 property transactions each day and leaving buyers in high-risk areas without flood insurance coverage, according to the National Association of Realtors.

Existing flood insurance policies will remain active, including a 30-day grace period, and can be transferred to new owners, according to the NAR.

NFIP claims will continue to be paid, but for how long will depend on the shutdown's duration, NAR said.

— Ana Teresa Solá

The biggest immediate housing impact from the government shutdown will be on mortgage rates.

Mortgage rates loosely follow the 10-year treasury, which dropped today, so rates could come down. That would be a change from recent mortgage rates, which were just at a three-week high.

The National Flood Insurance Program will also be affected. The program will continue to pay out claims for existing policyholders, but it won't write new policies or renew existing policies. A lapse would affect about 1,300 property sales per day, according to the National Association of Realtors.

Despite the delay, the home sales are expected to eventually close when the shutdown lifts.

The Federal Housing Administration's mortgage program, which provides low-down-payment loans to borrowers with lower credit scores, will still operate to endorse new single-family mortgages, but likely at reduced capacity, slowing the process for borrowers. It'll be the same for mortgage loans guaranteed by the U.S. Department of Veterans Affairs.

The exception will be for products such as home equity conversion mortgages and Title I loans. Critical FHA operations such as claim payments, mortgage servicing, loss mitigation, and REO property management will continue. Activities requiring direct staff input, such as some condo project approvals, are suspended, according to the National Association of Realtors.

The U.S. Department of Agriculture will halt issuance of new direct and guaranteed home loans, and any scheduled direct‑loan closings will be postponed. Pending conditional commitments for guaranteed loans are still being reviewed, but closings for guaranteed loans that do not yet have a guarantee will proceed only at the lender's risk. Disbursements on existing construction loans may continue, but only when doing so is necessary to protect USDA's property interests, according to the National Association of Realtors.

— Diana Olick

The federal government's shutdown prompted agencies to temporarily stop or limit some services, leaving Americans wondering what's being affected.

Here's a list detailing immediate shutdown impact:

Mail services: The U.S. Postal Service said its services would not be interrupted by a shutdown. All post offices will remain open, the USPS said.

Nutritional programs: The Supplemental Nutrition Assistance Program — also referred to as SNAP or food stamps — will continue running, according to the Department of Agriculture. The Special Supplemental Nutrition Program for Women, Infants, and Children, known as WIC, will also keep going. Notably, the department said the programs' continuation is "subject to the availability of funding."

Public health care: Medicare will continue to perform its full services, according to the Department of Health and Human Services. The agency also said that it expects to have "sufficient funding" for Medicaid for the first quarter of the 2026 fiscal year.

Courts: The U.S. court website said the judiciary will remain open with paid operations through Oct. 17. Most proceedings and deadlines are expected to take place as scheduled.

Banks: Private banks should be unaffected by the shutdown.

Economic data: The Labor Department said economic data will not be collected or published during the shutdown. That means previously expected releases, such as Friday's nonfarm payroll report, will not come out as scheduled.

National parks and monuments: National parks will be partially open, according to the Interior Department. Open-air sites and memorials would be available to visit, but buildings that need staffing will shutter.

Student loans: Federal student loans still need to be paid. However, applications for loan forgiveness to the Department of Education are expected to see further delays as a result of the shutdown. The department said it would furlough around 95% of its non-Federal Student Aid staff for the first week of the shutdown.

Social Security: Social Security and Supplemental Security Income payments will continue as expected, according to the Social Security Administration. Local offices will remain open but offer reduced services.

Schools and libraries: Schools and colleges tend to see little impact on day-to-day operations during short-term government shutdowns. However, the Library of Congress said all buildings will be closed and public events canceled. 

Military: Most military operations and veterans benefits will continue, though worker pay is delayed during a shutdown, according to the Department of Defense. No new orders can be issued outside of extenuating circumstances.

Air travel: Air traffic controllers and Transportation Security Administration officers will keep working, but without pay. The Department of Transportation will stop hiring for a variety of roles related to aviation safety.

Rail travel: Amtrak told CNBC it will continue "normal operation" of its passenger rail network.

— Alex Harring

"We are going to have to lay some people off if the shutdown continues," Vice President JD Vance said.

"We don't like that," Vance said at a White House press briefing. "We don't necessarily want to do it, but we're going to do what we have to keep the American people's essential services continuing to run."

Asked why the Trump administration is forecasting layoffs when prior shutdowns have not led to that outcome, Vance said, "We haven't made any final decisions."

Office of Management and Budget Director Russell Vought told House Republicans during a conference call that the Trump administration will carry out reductions in force among federal workers in one or two days, according to a person familiar with the matter.

White House press secretary Karoline Leavitt confirmed during the briefing that she expected layoffs to begin "very soon," possibly within "two days."

Vought also said that the Women, Infants, and Children nutrition program will run out of funding by next week if the government remains shut.

— Dan Mangan and Emily Wilkins

The White House ratcheted up the pressure — and the blame — on Democrats during a press briefing more than 13 hours into the shutdown, urging them to abandon key demands.

Vice President JD Vance said in a White House press briefing that policy disagreements should not "serve as the basis for a government shutdown."

He and White House press secretary Karoline Leavitt zeroed in on the standoff over health care, doubling down on their claims that Democrats want to give health care to "illegal immigrants."

Federal law prohibits funding health care for undocumented immigrants, and Democrats are not advocating for such a move.

Democrats say they want to restore health care coverage options that were available to some immigrants before Trump's "One Big Beautiful" tax bill earlier this year.

This has been a key sticking point in the impasse.

"I think it's important to bracket the health care policy conversation, because it's separate from the government shutdown," Vance said.

"We think that we can open the government and then have the conversation about what best health care policy to fit the needs of the American people."

— Erin Doherty

Fitch Ratings said Wednesday that the shutdown should not affect U.S. credit ratings.

"The U.S. government shutdown does not have near-term implications for the 'AA+'/Stable U.S. sovereign rating," the U.S. credit ratings firm said in a press release.

However, Fitch said the shutdown "highlights long-standing policymaking weaknesses and political brinkmanship around budgetary issues."

Fitch downgraded the U.S. long-term credit rating to AA+ from AAA in 2023, citing expectations for "fiscal deterioration" and instances of "political standoffs."

— Alex Harring

The U.S. Securities and Exchange Commission has "very limited" staff available to respond to emergency situations, according to a message on its website.

The agency's electronic data-gathering system, known as EDGAR, will continue to operate, the message said.

That program, which stands for the Electronic Data Gathering, Analysis and Retrieval system, is the SEC's free public database of filings from publicly traded companies, mutual funds, ETFs and other entities that report to the SEC.

The SEC's website message noted that the agency "has staff available to respond to emergency situations with a focus on the market integrity and investor protection components of our mission."

Rep. Maxine Waters, D-Calif., the ranking member on the House Financial Services Committee, in a statement said that the SEC "has furloughed 91 percent of its staff, leaving financial markets and investors at great risk at a time when strong oversight is needed most."

— Stephanie Dhue

Banks and most credit unions are open and operating normally during the government shutdown, as are their main regulators, people with knowledge of the situation told CNBC.

Banks are private companies, and their regulators, including the Federal Reserve and Consumer Financial Protection Bureau, aren't subject to the annual appropriations process, said these people, who declined to be identified speaking about the shutdown.

The Federal Deposit Insurance Corporation is funded by member banks, so the industry's deposit insurance shouldn't be disrupted, either.

JPMorgan Chase, the nation's largest bank, is "continuing normal operations," a company spokesman said.

While the National Credit Union Administration, which insures credit union deposits, said it remains open, it did warn of possible "service interruptions" to credit union offices that are located on federal property.

That warning was echoed by the main credit union trade group: "Credit unions that have branches in government buildings or on federal property may experience service interruptions."

That could compound issues faced by federal employees and servicemembers who are no longer being paid during the shutdown, the trade group said.

Another area of possible disruption: Small business owners seeking federally backed loans might not be able to apply for them.

The Small Business Administration, which partners with banks to offer the guaranteed loans, said that the shutdown is "stopping an estimated 320 small businesses from accessing $170 million in SBA-guaranteed funding" every day.

— Hugh Son

The Senate again rejected House Republicans' stopgap funding bill, prolonging the shutdown with no end in sight.

It was the second time in less than 24 hours that lawmakers in the Senate voted on the continuing resolution, which would fund the government through Nov. 21.

The measure did not advance in a 55-45 vote, the same outcome as Tuesday night. It needed 60 votes to advance.

The vote largely fell along party lines, but as was the case on Tuesday, Sens. John Fetterman, D-Pa., Catherine Cortez Masto, D-Nev., and Angus King, I-Maine, voted with Republicans in support of the measure.

— Erin Doherty

Federal student loan borrowers have already struggled with accessing repayment plans and debt forgiveness under the Trump administration. The shutdown will likely make things worse.

More than a million borrowers are in a backlog to enroll in an income-driven repayment plan, or IDR, the Trump administration revealed in court records last month.

Meanwhile, 74,510 people are waiting for a determination from the U.S. Department of Education on their Public Service Loan Forgiveness status, the court records show.

During the shutdown, Federal Student Aid staff "will not be able to perform regular operations, including working on the IDR backlog," a spokesperson for the Education Department told CNBC.

However, an Education Department memo notes, "borrowers are expected to continue repayment throughout a shutdown."

— Annie Nova

The stock market turned positive Wednesday morning as traders attempted to shake off shutdown-related concerns weighing on Wall Street.

The Dow Jones Industrial Average added more than 100 points in late morning trading, despite falling more than 120 points at session lows. The broad S&P 500 and technology-heavy Nasdaq Composite also both climbed into the green after trading in the red for much of the morning.

Follow live markets updates here.

— Alex Harring

Members of Congress will still get paid during the shutdown. Their staffers may not be so lucky.

Their salaries are protected under Article I of the Constitution, which states, "The Senators and Representatives shall receive a Compensation for their Services, to be ascertained by Law, and paid out of the Treasury of the United States."

The people who work for them, however, do not have those protections. Lawmakers can decide for themselves which of their staff members are essential and can continue to work. 

The Capitol Visitors Center is closed, and there are no tours. Janitor service is discontinued. 

The Government Employee Fair Treatment Act of 2019 guarantees back pay for all federal employees, regardless of their work status during the shutdown.

Most members of Congress receive an annual salary of $174,000.

— Stephanie Dhue

The Senate once again voted not to advance the Democratic-backed continuing resolution to fund the government on a short-term basis.

The final vote — which fell along party lines, as was expected — was 47-53.

The Senate previously shot down both the Democratic proposal and a House-passed Republican alternative on Tuesday night, in a failed 11th-hour bid to avert a shutdown.

— Erin Doherty

Senate Minority Leader Chuck Schumer, D-N.Y., said Republicans "tried to bully" Democrats into voting for the short-term resolution to fund the government.

"And it's clear they can't, they don't have the votes," he said from the Senate floor, hours after the shutdown took effect.

"Donald Trump and Republicans have barreled us into a shutdown because they refuse to protect Americans' health care," he said.

Schumer and his Democratic colleagues have remained dug in on demands that any legislation to fund the government includes health care provisions, specifically codifying an extension of the Affordable Care Act tax credits, currently due to expire at the end of the year.

Republicans, however, insist that such discussions should not happen during the current funding negotiations.

— Erin Doherty

The website for the U.S. Treasury Inspector General for Tax Administration, or TIGTA, was "currently unavailable" on Wednesday morning, with a message citing "a lack of apportionment of funds."

The agency said in an email that it would post its latest audits, inspections and evaluations on LinkedIn, X and via its newsletter.

TIGTA provides independent oversight within the Treasury Department.

— Kate Dore

A new analysis found that average premiums for health insurance purchased through the Affordable Care Act marketplace will more than double in 2026, if the enhanced tax credits that make such health plans cheaper are allowed to expire at year's end.

If those subsidies lapse, recipients would see their premiums increase to $1,906 from $888, on average — a 114% increase, according to an analysis by KFF, a nonpartisan health policy research group.

Democrats are demanding that any deal to end the shutdown include an extension of the ACA subsidies, known as "premium tax credits."

Democrats enhanced the credits as part of a 2021 pandemic relief law and did so again in 2022 on a temporary basis. The enhanced subsidies made health premiums cheaper and expanded the number of households eligible for them.

About 22 million Americans receive the enhanced subsidies.

— Greg Iacurci

College-bound students and their families can still apply for financial aid during the shutdown through the government's Free Application for Federal Student Aid form.

But the Department of Education warned that information on its website "may not be maintained, and inquiries may not receive a response" while the government remains unfunded.

The 2026 FAFSA filing season officially opened last week. Many families heavily rely on financial aid to help cover the cost of college, and experts often recommend filing for aid as early as possible.

— Jessica Dickler

To predict what factors might ultimately push politicians to bring the current shutdown to an end, Wall Street analysts are looking to the past.

Citi's Daniel Tobon wrote in a client note that the last shutdown, which began in late 2018 during Trump's first term, was resolved partly due to frustration over increasing delays at airports.

Raymond James analyst Ed Mills specifically pointed to the temporary shutdown of operations at New York's LaGuardia Airport in 2019 as a crisis that forced politicians' hands.

Furloughed federal workers going without a second paycheck during that shutdown also added to pressure, Tobon said.

This time around, partial funding lapses for Defense Department staff are generating concerns around military pay, Mills noted.

Evercore ISI strategist Sarah Bianchi said federal worker layoffs could push Democrats to acquiesce.

"During the shutdown, the press will be writing on a whole array of local shutdown-related disruptions, from longer-than-usual TSA lines at airports to towns that depend economically on nearby national parks being open," Bianchi wrote to clients Tuesday.

"If any of these stories go viral, it could shape the national narrative and push both sides to compromise sooner."

— Alex Harring

House Speaker Mike Johnson, R-La., said he hopes that Senate Democrats "come to their senses soon" and vote for the GOP's continuing resolution to temporarily fund the government.

"The longer this goes on, the more pain will be inflicted," he said during a news conference Wednesday morning alongside other Republican leaders.

"Every single bit of this was entirely avoidable," Johnson said.

Johnson and other GOP leaders repeatedly put the onus on Democrats for the shutdown.

"Democrats want to play the emotional games with the lives and the likelihood of Americans," Johnson said.

"Unfortunately, we are here this morning, in a government shutdown that Democrats wanted," Senate Majority Leader John Thune, R-S.D., said at the presser.

"This could have been avoided," Thune added.

Both parties have blamed each other for the shutdown, underscoring the partisan gridlock that has stalled negotiations.

— Erin Doherty

The Department of Health and Human Services said in its contingency plan that it expects more than 32,000 of its almost 80,000 staff to be furloughed during the shutdown.

The agency oversees the federal health agencies responsible for tracking disease outbreaks, approving new drugs and funding scientific research, among other efforts critical to public health. That includes the Centers for Disease Control and Prevention, the Food and Drug Administration and the National Institutes of Health. 

HHS said some activities will continue, such as the ability to respond to pandemics, flu and hurricanes and to monitor disease outbreaks. The NIH will also continue research and clinical services necessary to protect human life and government property.

But HHS said research contracts and grants to external organizations, such as universities, will freeze during the shutdown. The NIH will not admit new patients to its research hospital unless medically necessary, while the CDC will be "hampered" in its ability to provide the public with health-related information, HHS said.

The FDA will not process new drug applications and medical device submissions, or support staff that work to protect patients from unsafe or ineffective drugs, unless it is an imminent threat. The FDA also won't be able to monitor the use of new ingredients in animal food, preventing the agency from ensuring that meat, milk and eggs of livestock are safe for the public to eat.

— Annika Kim Constantino

John Mullen, president and CEO of Parsons Capital Management — which ranked No. 1 on CNBC's Financial Advisor 100 for 2025, a list of the top 100 financial advisors in the U.S. — said he has viewed previous government shutdowns mostly as "short-term blips."

"Very rarely does it have some sort of lasting impact," Mullen told CNBC in an interview Wednesday morning.

He said the firm's investment approach reflects a longer-term view. "In general, we don't think this is going to disrupt the major trends that we've identified and are enthusiastic about," he said.

Those trends include artificial intelligence, quantum computing and the companies poised to benefit from a broader deregulation push, he said.

Still, this shutdown could be riskier because of the Trump administration's threat to make some federal government furloughs permanent.

"If the government does follow through on plans to fire workers, that does change the calculus," Mullen said. Massive job losses "could have a true lasting negative impact," particularly at a time when "our economy is not roaring along," he said.

— Jessica Dickler

The federal government shutdown won't stop Social Security checks from being sent out — but it may affect certain services that beneficiaries rely on.

Trump said on the eve of the shutdown that the federal funding lapse may lead to "irreversible" actions, such as cutting benefits for social programs. Trump did not elaborate on exactly which programs could be affected. The White House did not immediately respond to a request for further information.

"We're still telling people that checks are going out," said Maria Freese, senior legislative representative at the National Committee to Preserve Social Security and Medicare.

In a Sept. 24 contingency plan, the Social Security Administration outlined the services that would and would not be available in the event of a government shutdown.

Out of more than 51,000 employees, around 6,000 will be furloughed, the agency said.

Among the services that will continue are applications for benefits, requests for appeals and issuance of original and replacement Social Security cards, the agency said.

Services slated to be discontinued include benefit verifications, earnings record corrections and updates, replacement Medicare cards and overpayments processing, it said.

— Lorie Konish

Senate Minority Leader Chuck Schumer, D-N.Y., called Republican claims that Democrats were shutting down the government to give health care to undocumented immigrants "a total, absolute, effing lie."

"They [Republicans] are afraid of the truth," Schumer said on MSNBC's "Morning Joe."

"They know what they've done to health care has decimated health care for so much of America."

"There are Republicans on the Senate side who are saying, 'Let's sit down and negotiate,'" he said.

"We should, and it has to, by the way, it's not just [Senate Majority Leader John] Thune. It has to include [House Speaker Mike] Johnson," he said.

— Luke Fountain

Ford Motor CEO Jim Farley said neither the U.S. economy nor the business community need a government shutdown right now, amid this "sensitive time for our country."

"It's not a good thing," Farley said Tuesday on CNBC's "Squawk Box." "We really need the leaders in D.C. to come together. It's a very sensitive time for our country. We need the leadership to unite. We cannot have a shutdown. That is bad for the economy and bad for our country."

Farley's comments came as the automaker was hosting an inaugural event in Detroit to promote the "essential economy" of U.S. skilled trades and labor.

– Michael Wayland

The Federal Trade Commission said it will be closed during the shutdown, preventing consumers from reporting fraud.

"The FTC is closed due to the lapse in funding," the agency's website currently says.

The FTC is in charge of protecting consumers from unfair and fraudulent business practices. It also has oversight of anticompetitive mergers and partnerships.

The closure "means we won't be able to answer your questions on X. Consumers cannot report fraud or register for Do Not Call during this time," the agency's Office of Technology said in a post on X.

On Tuesday, the FTC announced a lawsuit against real estate giants Zillow and Redfin alleging antitrust violations.

— Luke Fountain

The Senate rejected a last-ditch measure on Tuesday evening to keep the government funded through Nov. 20.

The final vote was 55-45, falling short of the 60-vote threshold that would have passed the measure in the upper chamber.

Sen. Rand Paul, R-Ky., voted with Democrats to oppose the measure, while Sens. John Fetterman, D-Pa., Catherine Cortez Masto, D-Nev., and Angus King, I-Maine, voted with Republicans in support.

Senate Majority Leader John Thune, R-S.D., presides over a razor-thin majority, so he needs at least seven Democrats to vote with his party to get any legislation passed.

Senate Minority Leader Chuck Schumer, D-N.Y., however, is trying to keep his Democratic colleagues on board with his effort to stand firm on his party's health care demands.

Schumer has faced pressure from the progressive wing of his party to oppose any government funding legislation unless it includes key health-care concessions.

— Erin Doherty

With all eyes on the impending government shutdown, the White House confirmed late Tuesday that it withdrew the nomination of E.J. Antoni, Trump's pick to lead the U.S. Bureau of Labor Statistics.

Trump nominated Antoni, an economist with the conservative think tank the Heritage Foundation, after he fired former BLS Commissioner Erika McEntarfer in response to her agency releasing a weak monthly jobs report.

Antoni "is a brilliant economist and an American patriot that will continue to do good work on behalf of our great country," a White House official told CNBC in a statement Tuesday night.

"President Trump is committed to fixing the longstanding failures at the BLS that have undermined the public's trust in critical economic data. The President plans to announce a new nominee very soon."

Antoni's nomination wasn't the only one yanked late Tuesday: The White House also withdrew Brian Quintenz's nomination to chair the Commodity Futures Trading Commission, Politico reported.

CNN first reported Antoni's withdrawal.

— Kevin Breuninger

The ADP's private payroll report came in surprisingly weak on Wednesday, offering a negative reading of the labor market with other big job data releases in limbo.

Private payrolls lost 32,000 jobs on a seasonally adjusted basis in September, marking the biggest decrease since 2023. Economists polled by Dow Jones had been expecting payrolls to add 45,000 roles in the month.

This report comes hours into the government shutdown, which would inhibit releases on nonfarm payrolls and jobless claims previously expected for later this week if a resolution isn't reached. In such a situation, the ADP's data could take on more significance than it typically does for economic policymakers and investors looking to assess the labor market's health.

— Alex Harring, Jeff Cox

The official website of the U.S. Department of Housing and Urban Development is prominently displaying a politically partisan message blaming Trump's political opponents for the government shutdown.

Visitors to the site are currently greeted with a pop-up message reading, "The Radical Left in Congress shut down the government. HUD will use available resources to help Americans in need."

After closing that window, the same message appears in a bright-red banner at the top of the site.

The politically charged message is highly unusual for a government website. Some critics are questioning whether the language violates the Hatch Act, the law limiting political conduct by federal employees.

— Kevin Breuninger

Air traffic controller training will continue at the U.S. academy in Oklahoma as well as in the field, according to a Department of Transportation shutdown contingency plan.

The U.S. has ramped up hiring of new air traffic controllers, though training takes months. Thinly staffed facilities, such as those serving airports in the New York City area, have disrupted flights in recent years, angering travelers and airline executives alike.

In the shutdown, 13,294 air traffic controllers will continue to work, though without pay, according to the DOT. More than 11,000 FAA employees are subject to furlough, the agency said.

A more than one-month government shutdown ended in January 2019 after a shortage of air traffic controllers sparked disruptions at New York City airports.

— Leslie Josephs

Air travel will continue during a government shutdown, meaning passengers can still board flights and go through security as usual.

But Airlines for America — a trade group that represents major carriers like Delta Air Lines, United Airlines, American Airlines, Southwest Airlines and others — warned that the aviation system "may need to slow down, reducing efficiency" during a shutdown.

Government workers who are considered "essential," like TSA officers and air traffic controllers, are required to continue working.

The shutdown could cost the U.S. travel industry $1 billion per week, according to estimates from the U.S. Travel Association, which represents major hotel groups and others.

"The longer a shutdown drags on, the more likely we are to see longer TSA lines, flight delays and cancellations, national parks in disrepair and unnecessary delays in modernizing travel infrastructure," Geoff Freeman, the group's president, said in a statement.

When the government shut down under the first Trump administration in late 2018 and early 2019, callouts from a few air traffic controllers along the U.S. East Coast snarled air traffic, putting pressure on lawmakers to reach a deal.

— Michele Luhn

Sen. Steve Daines urged Democrats to approve a temporary funding extension so the shutdown can end and the two parties can reach a long-term agreement.

"This will come to an end," the Montana Republican told CNBC Wednesday morning. "But in this particular case, it will come to an end when five Democrats join the rest of us and pass this temporary extension."

Daines said negotiations over the appropriation process had been "going very well" until Senate Minority Leader Chuck Schumer, D-N.Y., "decided to shut things down." Schumer is "yielding" to the far-left side of his party in allowing a shutdown, Daines said.

"There's no reason we should be in a shutdown," Daines said. "It costs the taxpayer money, it disrupts government services, and at the end of the day, it doesn't really deliver any political or policy objective."

— Alex Harring

Gold prices rallied to fresh records Wednesday morning as the shutdown sent investors seeking safe-haven trades.

Spot gold was trading at $3,893.06 early Wednesday morning. U.S. gold futures for December delivery popped to $3,918.10, rising closer to the closely followed $4,000 mark.

Gold has long been considered a risk-off asset for investors that can provide refuge during times of economic and political turmoil.

— Alex Harring

Evercore ISI strategist Sarah Bianchi doesn't expect a long government shutdown after a few Senate Democrats voted for a stopgap funding bill last night that ultimately fell short of the required votes.

"Three Senate Democrats voted for the bill tonight, offset by one Republican against. There are certainly five more Senate Democrats who are uncomfortable with shutdowns and will not want this to go on very long, especially if the threat of federal worker layoffs becomes more real. Given this, and the fact that Republican leaders already have expressed openness to negotiating on health care, we think the shutdown will be relatively short," she wrote in a note.

— Fred Imbert

William Lee, chief economist at the Milken Institute, noted this shutdown could have a greater impact on the economy than previous ones.

"The history of shutdowns really has had so little impact on the real economy because essentially, by the end of the shutdowns, everything goes back to the way it was," he said Wednesday in a "Worldwide Exchange" interview. "But this time there may be some big changes because both sides are being very strategic about it. The Republicans are saying, 'this is a good time for us to implement the kind of changes Elon Musk put in place with DOGE.' ... The Democrats are really bearing down and saying, 'this is our turn to be strategic and get back the legislation we want to put in place."

He added that both sides are playing more "chess than checkers."

— Fred Imbert

U.S. stock futures were under pressure Wednesday after lawmakers failed to reach a deal that would avoid a government shutdown.

Futures tied to the Dow Jones Industrial Average dropped 241 points, or 0.5%. S&P 500 futures shed 0.6% along with Nasdaq-100 futures.

— Fred Imbert

A shutdown could delay the release of key economic reports that the government regularly publishes, which are closely watched by financial markets.

In a contingency plan released Friday, the Labor Department said that the Bureau of Labor Statistics, the agency that produces the government reports on the economy, will "suspend all operations" in the event of a shutdown.

"Economic data that are scheduled to be released during the lapse will not be released," the plan said.

The next BLS employment report was set to be released Friday. The BLS's Consumer Price Index reading for September is scheduled to be released on Oct. 15.

Wells Fargo economist Michael Pugliese noted last week that after the last full government shutdown in 2013, the monthly jobs and consumer price index reports "were delayed by about two weeks."

"Collection, processing and publication delays stretched into the following month as well," Pugliese noted.

In the partial shutdown that began in late 2018, Pugliese noted, "the first look at" gross domestic product growth for the fourth quarter of that year "was delayed about a month, as was December 2018 data on retail sales and personal income & spending."

— Kevin Breuninger and Jeff Cox

European markets were slightly higher during early morning deals, as global investors monitor the U.S. government shutdown.

The pan-European Stoxx 600 index was up 0.1% shortly after the opening bell, with sectors and major bourses pointing in opposite directions.

— Chloe Taylor, Tasmin Lockwood

Market participants are likely to brush off the impact of the government shutdown, according to Luke Bartholomew, deputy chief economist at Aberdeen, particularly if it proves to be a short-term issue.

Asked whether investors were likely to take issue with the shutdown, Bartholomew replied: "Probably not, to be honest. I mean, if it was bound up with the debt ceiling issue as they have been in the past then potentially there's risks around that, but I would be surprised if the market doesn't ultimately shrug this off."

Bartholomew conceded there are questions about data availability, with the closely watched nonfarm payrolls report not expected to be released on Friday because of the shutdown.

"Maybe that influences the Fed in some way. Although they do have a wide variety of other private sector data that they can rely on," Bartholomew told CNBC's "Squawk Box Europe."

— Sam Meredith

Republicans, who hold the White House and slim majorities in both chambers of Congress, wanted to pass a stopgap bill to maintain funding at current levels until late November. They needed at least seven Democrats to help them in the Senate, where 60 votes are required to overcome the filibuster.

Senate Minority Leader Chuck Schumer, D-N.Y., and a group of Democrats had previously joined Republicans in March to pass a six-month extension of government funding.

But this time around, Democrats have united around several demands, including that any short-term funding bill include an extension of enhanced Obamacare tax credits, which are due to lapse at year's end. The enhanced subsidies reduce the costs of health insurance premiums for a wider swath of Affordable Care Act enrollees.

Republicans balked, accusing Democrats of holding the government hostage by standing in the way of continued federal funding unless their health-care demands are met.

GOP leaders have also argued that their "clean" continuing resolution is nonpartisan, and that policy negotiations can continue without shutting down the government.

Democrats countered that the GOP proposal actually is partisan, since Republicans are seeking to extend funding following the passage of a controversial spending bill that narrowly passed in July over the objections of all congressional Democrats.

Democrats have also slammed Republicans for refusing to negotiate, and for leaving Washington, D.C., as the shutdown deadline approached.

Trump and other Republicans have also accused Democrats of seeking to give health-care benefits to undocumented immigrants — a claim that Democrats reject as a lie, noting that federal law prohibits it.

— Kevin Breuninger

While insisting that Republicans do not want to shut the government down, Trump said his administration could exploit the situation to hurt Democrats.

"We can do things during the shutdown that are irreversible, that are bad for [Democrats]," Trump said at the White House on Tuesday, "like cutting vast numbers of people out, cutting things that they like, cutting programs that they like."

That could include cutting "large numbers of people" on government benefits, Trump said, before quickly adding, "We don't want to do that, but we don't want fraud, waste and abuse."

— Kevin Breuninger

"Democrats Have Shutdown the Government," a White House webpage said right after midnight, featuring a clock detailing the time that has passed since the shutdown began.

But California Gov. Gavin Newsom, a Democrat, said on X, "Donald Trump just shut down the government," underscoring the fact that both parties blame the other for the dramatic pause in federal services and functions.

Former Vice President Kamala Harris posted on X: "President Trump and Congressional Republicans just shut down the government because they refused to stop your health care costs from rising. Let me be clear: Republicans are in charge of the White House, House, and Senate. This is their shutdown."

— Dan Mangan, Riya Bhattacharjee

During the last full government shutdown in 2013, about 850,000 federal employees were furloughed, meaning they were required to take unpaid leave, according to the Committee for a Responsible Federal Budget.

The Congressional Budget Office estimated Tuesday that the current shutdown would lead to about 750,000 employees being furloughed.

"The total daily cost of their compensation would be roughly $400 million," the CBO told Sen. Joni Ernst, R-Iowa, in response to her request for information on the impact of a shutdown.

The agency's estimate noted that the number of furloughed employees could vary from day to day "because some agencies might furlough more employees the longer a shutdown persists and others might recall some initially furloughed employees."

Furloughed workers will get back pay upon their return.

But Trump's Office of Management and Budget has threatened to make some of those job cuts permanent, by warning federal agencies in a recent memo to prepare for mass firings in the event of a shutdown.

— Kevin Breuninger

The full shutdown began at midnight Wednesday after Democratic and Republican leaders failed to agree on even a short-term deal to keep the government fully funded past the current fiscal year.

It is unclear just how long the shutdown will last, or how widespread its impacts will be.

The federal government has either shut down or experienced funding gaps 14 times since 1980.

The longest shutdown on record started in late 2018, when the government partially shuttered for about five weeks amid disputes over funding Trump's proposed U.S.-Mexico border wall.

— Kevin Breuninger