Update: DoD confirms ground rules for possible shutdown: Pay stops, mission continues: Shutdown 101 for troops and families.

If you were around in 2013, you’ll remember the many ways the two-week government shutdown that October affected military personnel and their families: Everything from doctor’s appointments to planned relocations to death benefits.

Operations that are considered essential to national security will continue during the shutdown. Defense Department officials set those ground rules; the current guidelines weren’t immediately available.

But as the Friday night deadline looms for lawmakers to reach an agreement, shutdown preparations are underway in DoD.

“DoD’s foremost need is to receive an enacted appropriation for fiscal year 2018 as soon as possible,” DoD spokesman Army Maj. Dave Eastburn said. “We are hopeful that there is enough time for Congress to prevent a lapse in appropriations. However, at this time, prudent management requires planning for the possibility of a shutdown.”

Based on some shutdown history and recent guidelines, we put together some points to consider.

Pay. Active-duty military personnel generally report to work during a shutdown regardless of whether their command is considered “essential,” but military personnel generally wouldn’t be paid until the shutdown ends.

This could change if Congress passes a law that requires the military to be paid during the shutdown, as they it in 2013. Personnel are paid on the 1st and 15th of each month.

In the past, a number of financial institutions that serve the military community have stepped up to fill the gap, in some cases offering to advance the active-duty pay, then recouping it later, when retroactive pay caught up.

Military relief societies also have helped service members and families fill the gaps during shutdowns.

Retired pay is not affected. It comes from a different pot of money.

PCS and TDY. In 2013, permanent change-of-station moves and temporary duty travel were canceled except for service members traveling to activities and operations determined to be essential to national security.

Health care. In 2013, military treatment facilities remained open to care for existing patients and provide emergency services and acute care. Routine appointments and elective surgery were suspended, but pharmacy, laboratory and radiology services continued. All care through off-base civilian Tricare providers was unchanged.

Commissaries. DoD hasn’t notified commissary officials yet about whether they will have to close any stores, Defense Commissary Agency spokesman Kevin Robinson said. Commissaries were closed during the 2013 shutdown, except for overseas stores.

If there is a shutdown, the commissaries forced to close will follow an orderly procedure to allow store staffs to reduce stocks of perishables, safeguard equipment and facilities, and make other necessary preparations, he said.

In 2013, commissaries in the continental U.S., as well as those in Alaska and Hawaii, were open an extra day after the shutdown took effect. They were packed with customers.

“In the event of a shutdown, we will do our best to support our military communities whenever and wherever possible,” Robinson said.

Exchanges. They won’t close, because they don’t rely on taxpayer dollars. But they do try to ease some of the strain on the customers affected by commissary closures. For example, Army and Air Force Exchange Service officials already are working up emergency orders for key items such as diapers, bread, milk and frozen food, and working with distributors to speed up those deliveries for early next week, AAFES spokesman Chris Ward said.

DoD schools. Based on past experience, the Department of Defense Education Activity is planning that their 166 DoD schools overseas and stateside, and eight district offices around the world, would be allowed to continue to operate, DoDEA spokesman Frank O’Gara said.

A shutdown would probably curtail operations at regional offices and at headquarters, he said, though DoDEA is awaiting DoD guidance.

Death gratuities. These $100,000 payments might not be made immediately to the designated survivor of a service member who dies on active duty. When those payments went unmade in 2013, the Fisher House Foundation stepped in to fill the gap. After the government reached a deal to reimburse the charity, Congress eventually passed a law that restarted the payments.

Child care . This might be a mixed bag: In 2013, each installation determined whether child development centers continued to operate.

Previous guidance has allowed morale, welfare and recreation activities to operate during a shutdown if they are deemed necessary to support essential operations. That covered mess halls, physical training and child care activities required for readiness.

More MWR. In the past, MWR activities that are funded entirely by nonappropriated funds, not by taxpayer dollars, weren’t affected by the shutdown. A bowling center or golf course funded by customers likely would remain open, for example.

DoD civilians. In 2013, about 400,000 DoD civilians ― including military spouses, veterans and retirees ― were furloughed.