On Tuesday, the United States government began shutting down nonessential operations and furloughing as many as 400,000 civilian employees. The reason? Congress, divided over the Affordable Care Act, was unable to pass a continuing resolution that would keep the lights on through the start of the new fiscal year. As a result, any agencies that needed appropriations are now without funding and can not legally operate, with the exception of those duties that are considered necessary to protect life and property.

President Obama wrote a letter to employees of the federal government on Tuesday, saying that he will do “everything in my power to get the House of Representatives to allow our Government to reopen as quickly as possible, and make sure you receive the pay that you have earned.”

Here are some of the government agencies that will be hit hardest.

1. Department of Homeland Security

During the 2011 brinkmanship that threatened a government shutdown, contingency plans were drafted that categorized approximately 85 percent of DHS works as essential. As a result, the department is set to furlough about 31,295 employees, or around 13.5 percent of its total workforce of 231,117.

The DHS will only shut down what are considered to be noncritical operations, such as non-disaster grants programs administered by the Federal Emergency Management Agency. Government components such as the Transportation Security Agency, the Coast Guard, and Customs and Border Protection all fall under the DHS, and each will retain most of its workforce throughout the shutdown. About 11 percent of Secret Service employees are expected to be furloughed.

2. Department of Commerce

The Commerce Department is set to furlough 40,234 employees, or nearly 87 percent of its 46,420 person workforce. Employees within the patent office get to stay on the job because they can use revenue from fees to remain open, although, if the shutdown persists long enough, even the patent office will have to close. Employees at the National Oceanic and Atmospheric Administration will also stay on the job, because the data they collect on the weather are critical to “protect life and property” within the country.

The construction spending report, which is issued jointly by the Commerce Department and the Census Bureau, will not be released next week because of the shutdown.

If no resolution is passed come Thursday, the weekly jobless claims report may also be AWOL. The Employment Situation report, due out Friday, is in the same boat. These reports are issued by the Department of Labor, which, according to a September 25 memo, would be forced to furlough 13,350 employees, or nearly 82 percent of its 16,304 person workforce.

3. Department of the Interior

The Department of the Interior is set to furlough 58,765 employees over the course of a week, or nearly 81 percent of its 72,562 person workforce, according to a summary document published September 26. The report states: “All areas of the National Park and National Wildlife Refuge Systems would be closed and public access would be restricted. The Bureau of Land Management would terminate all nonemergency activities on the public lands.”

The shutdown means that Yosemite National Park is closed on its 123rd anniversary.

“A total of 7,707 personnel would be excepted from furlough in order to protect life and property,” according to the report. “This includes 3,734 law enforcement personnel and 3,973 other employees. This number would decrease if the shutdown goes beyond two to three days as facilities are secured and other shutdown activities are completed to a total of 13,797. The majority of the personnel that are excepted are law enforcement, wildland fire, emergency response and security, animal caretakers, maintenance and other personnel that would be focused on the custodial care of lands and facilities and protection of life and property.”

4. Internal Revenue Service

According to a contingency plan document published by the agency on September 26, the IRS designates just 8,752, or 9.3 percent of its total workforce, as “excepted” employees in the case of a shutdown. These employees are mostly “engaged in the protection of life and property,” which includes activities such as processing certain tax returns, maintaining computer systems to prevent loss of data, and protecting and maintaining bankruptcy cases.

For those of you being audited — good news! All audit functions and examination of returns are non-excepted activities and will be suspended for the duration of the shutdown. Other non-excepted activities include taxpayer services (call centers will be closed), legal counsel, and all research and development activities.

5. Department of Defense

The DoD is expected to furlough a massive 400,000 employees, or 50 percent of its civilian workforce. All active duty military personnel would stay on the job and should receive paychecks on time. President Obama addressed the issue early this week, promising that troops would have the resources they need to complete their missions.

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