Yes, once you join the military, Uncle Sam may keep you there longer than you have planned — or that you can be recalled to active duty once you get out or retire.

There are several ways that can happen.

Voluntary Extension at Certain Duty Stations
As the name suggests, this extension is up to the service member. If you are serving in a designated assignment, location or unit, you can voluntarily extend your enlistment past your normal ending date.

If you do so, you are entitled to a Special Assignment Incentive Pay (AIP) of up to $1,500 monthly. The monthly pay, billets, locations, military specialties and limitations vary by service.

Stop-Loss Programs
Unlike the voluntary extension, this one happens whether a service member likes it or not. Under a program known as “stop-loss,” the military can keep you on active duty after your anticipated discharge date. This program has been around since 1984 and has been used a few times.

While currently not in effect, stop-loss can be activated at any time. It normally requires Congress to declare an act of war or national emergency; however, if Congress isn’t in session and the president decides that it is in the national interest, he or she can declare a national emergency and retain any or all military members on active duty for at least six months, or until Congress gets involved.

If you are stop-lossed, current rules order Uncle Sam to pay you $500 extra each month for your troubles.

In most instances, not every service member will be stop-lossed. There are skills-based and unit-based stop-loss programs. That means you may be involuntarily kept in the service if you have a certain valuable skill, or “in the interests of unit cohesion.”

Mobilization of Reserve Members
Most people know that reservists and National Guard members can be called to active duty and sent to war in certain cases. What they may not know is that many service members remain in the reserves for several years after they leave active duty.

The minimum length of service anyone can join the military for is eight years. If you read the fine print of your service contract, you may see that you serve on active duty for four years, and the Individual Ready Reserve (IRR) for another four years.

That means you are eligible for recall at any time during those remaining four years.

The IRR differs from the Active or Selected Reserves because they aren’t required to drill and don’t get paid. The IRR remains as an adjunct to the active forces in times of emergency.

The rules vary but, generally speaking, any reservist can be recalled to active duty for the duration of a declared war or national emergency, plus an additional six months. This emergency or war declaration must be issued by Congress. If Congress isn’t in session, the president can use his or her authority to recall them immediately.

Generally, the active reservist — those who are in the Guard and Reserve in a drilling status — get called first, then the IRR, then those who left active duty within the last five years, then those under age 60.

If there is no state of emergency, the president can recall up 200,000 reservists for at least 400 days. When the nation is under a state of national emergency, the president can activate up to one million reservists by his order.

The United States has been in a state of national emergency since Nov. 14, 1979, when Executive Order 12170 was issued by President Jimmy Carter 10 days after the start of the Iran hostage crisis. That order was continued by President Donald Trump in Nov. 2017.

You can be recalled to any branch and any specialty — it all depends on the needs of the military.

Retirees and Officers
When it comes to retaining and recalling retirees and officers, each military service handles the situation its own way.

For example, in the Navy, when an enlisted member retires after 20 years of active duty, they are transferred to the Fleet Reserve. They remain in the Fleet Reserve until they have a total of 30 years’ service, and then are transferred to the retired rolls. That means that, if you are a Navy retiree who retired nine years ago, you may be recalled to active duty if there is a reserve recall.

Other services don’t have that stipulation. That means if you retired as an enlistee or noncommissioned officer from a service other than the Navy, your time has been served and you will not be recalled.

Of course, everything is different for officers. When an officer retires, their commission normally remains in force and effect forever. In return for the privilege of being legally entitled to being addressed by their military rank and getting all their retirement benefits, they basically remain an “Officer of the United States” until death. They can resign their commission, but few do.

That means that, if there is a recall, the officers can be brought back without an act of Congress or presidential recall.