Congress must pass a budget before Sept. 30, or it faces partially shutting down the government for the second time in two years. Here's how we got to another potential shutdown. (Jayne W. Orenstein/The Washington Post)

With a potential government funding lapse drawing close, some financial planning now will help federal employees be ready if the money stops Oct. 1.

The good news for some is that the money won’t stop. For the most part, this involves those working for agencies that are  “exempt” from a shutdown because they don’t get their funding through the congressional appropriations process.

The largest of these is the U.S. Postal Service, which operates on income from postage and the items it sells. Other agencies, or parts of them, also have funding not subject to annual appropriations — for example, through fees they charge for their services, or from trust funds or multi-year budgets.

Exempt employees stay on the job. As Office of Personnel Management guidance puts it, “Employees performing those functions will generally continue to be governed by the normal pay, leave, and other civil service rules.”

[Van Hollen on government shutdown: Patients will be turned away from NIH]

For employees whose salaries are paid from appropriations, there is another distinction—“excepted” vs. “non-excepted.”

Excepted employees are those whose jobs involve the safety of human life, the protection of property, or certain other types of work designated by their agencies as necessary to continue. These are not necessarily the same as “emergency” employees who are expected to continue coming to work when agencies close for other reasons, such as for severe weather.

Each agency decides how and when it notifies employees about whether or not they are excepted.

Excepted employees are to continue reporting for work as normal during a shutdown, although for the meantime they will not be paid for that time. Because agencies are incurring “obligations to pay for services performed . . . those employees will be paid after Congress passes and the President signs a new appropriation or continuing resolution,” says the OPM guidance.

When a shutdown starts, non-excepted employees are to perform what the guidance calls “minimal activities as necessary to execute an orderly suspension of agency operations related to non-excepted activities.” That typically is to last about a half-day, and then furloughed employees are to leave the workplace. They are not to work while on furlough, even on a volunteer basis.

In the most recent shutdown, in 2013, this winnowing-out process resulted in only about 850,000 of the 2.1 million non-postal employees being put on furlough.

Whether furloughed employees later will be paid for that time is up to Congress and the White House. The precedent is that they are later paid, and legislation already has been offered in the Senate to guarantee it if a shutdown happens again. (There was a separate set of unpaid furloughs in some agencies in the spring and summer of 2013 related to “sequestration” budget caps; those employees were not later paid for that time.)

When the “excepted” employees, and potentially also the “non-excepted” employees, would get paid for the shutdown time depends on several factors. Since almost all employees are paid on a two-week cycle — which varies according to the payroll provider an agency uses — it’s possible that a shutdown would start and end within that period and there would be no practical impact on the next pay distribution. However, a longer shutdown could span several cycles.

In any event, all employees would be paid for work they performed up to the shutdown. Says the OPM guidance, “Although the payroll for the last pay period before the lapse will be processed potentially during a period of furlough, the minimum number of payroll staff necessary for this process will be excepted from furlough for the minimum time required to issue the checks, including checks for the last pay period before the lapse.”

Those who are furloughed could not substitute annual leave or other forms of paid time off for that unpaid time, and previously scheduled leave would be canceled. They could take other jobs but only those allowable under government ethics rules restricting outside income.

Further, they could apply for unemployment benefits, but states typically impose a waiting period of a week or more before benefits can begin. And if they are later paid for the furlough time, they would have to return any unemployment payments they received.

Employees on unpaid status may not borrow from their Thrift Savings Plan accounts. They could apply for a loan up to the shutdown, but they still would have to make the scheduled payments afterward — as would those who took one previously — or else face a tax penalty. A “financial hardship” withdrawal, which can be taken either in paid or unpaid status, might be another option but those have strict qualifying rules and also incur tax penalties.

Health insurance coverage continues during unpaid time. The enrollee share of the premiums accumulates and is withheld from salary once the employee returns to pay status.

For those enrolled in the long-term care or vision-dental insurance programs and who pay through payroll withholdings, premiums would accumulate for several unpaid pay periods. After that, they would be billed directly.

Life insurance coverage continues without cost to the employee for an unpaid period up to a year.