Under 10 U.S.C. § 12406, the President can order members and units of the National Guard into federal service when the United States faces invasion or the danger of invasion, when there is a rebellion or danger of rebellion against federal authority, or when the President is unable to execute the laws of the United States with regular forces alone.1Office of the Law Revision Counsel. 10 USC 12406 – National Guard in Federal Service: Call Federalizing the National Guard under 10 U.S.C. § 12406 pulls Guard members out from under their governor’s command and places them under the President as Commander in Chief. The statute sets no ceiling on numbers and gives the President wide discretion to decide when the triggering conditions apply.
The Three Statutory Triggers
Section 12406 lists three conditions, and any one of them is enough. The first is invasion, or the danger of invasion, of the United States or its commonwealths and territories. The second is rebellion or the danger of rebellion against the authority of the federal government. The third applies when the President is unable to execute federal law with regular active-duty forces.1Office of the Law Revision Counsel. 10 USC 12406 – National Guard in Federal Service: Call
The triggers are written broadly. An invasion does not have to be underway, and a rebellion does not have to be in progress. The danger of either is enough. The President decides how many Guard members to call and from which states, in “such numbers as he considers necessary,” so a call can range from a few hundred troops in one state to tens of thousands drawn from many.
Who Decides an Emergency Exists
The Supreme Court answered this question in Martin v. Mott (1827), holding that the President’s determination that a triggering condition exists is “conclusive upon all other persons” and not subject to second-guessing by the courts.2Justia. Martin v Mott, 25 US 19 (1827) That deference has never been overruled. Once the President issues the call, the existence of the emergency is generally treated as settled unless the invocation is challenged on other grounds, such as whether the statute actually authorizes what the President is trying to do with the troops.
Section 12406 and the Insurrection Act Are Different Statutes
Section 12406 is a call-up authority. It answers whether the President can order Guard members into federal service. It does not, standing alone, answer what those federalized troops can then be used for. That second question is the domain of the Insurrection Act, 10 U.S.C. §§ 251–255.
Section 251 lets the President send federal troops when a state’s own government asks for help suppressing an insurrection it cannot control.3Office of the Law Revision Counsel. 10 USC 251 – Federal Aid for State Governments Section 252 lets the President act without a state request when rebellion or unlawful obstruction makes it impossible to enforce federal law through ordinary judicial process.4Office of the Law Revision Counsel. 10 USC 252 – Use of Militia and Armed Forces to Enforce Federal Authority Before deploying troops under either provision, the President must issue a proclamation ordering those involved to disperse.5Office of the Law Revision Counsel. 10 US Code 254 – Proclamation to Disperse
From Little Rock in 1957 through the Los Angeles riots in 1992, every President who federalized the Guard for a domestic mission invoked both statutes together. The Insurrection Act provided the substantive authority to use military force domestically; § 12406 provided the mechanism to call up the Guard.6National Guard. Federalizations of the Guard for Domestic Missions Through 2025 That pattern broke in 2025, when President Trump invoked § 12406 alone to federalize 2,000 California National Guard members during immigration enforcement protests in Los Angeles, without invoking the Insurrection Act. A federal court ultimately ordered the federalization terminated. The episode forced a question earlier administrations had never tested: whether § 12406 by itself authorizes deployment of Guard members for domestic law enforcement, or whether it must be paired with the Insurrection Act for that purpose.
What Changes When the Guard Is Federalized
Under normal circumstances, Guard members serve in Title 32 status, meaning they answer to their state governor even though the federal government funds and regulates their training.7National Guard. National Guard Duty Statuses A § 12406 call-up shifts them into Title 10 status. The governor loses all authority over those units. The President becomes their Commander in Chief, exercising control through the Secretary of Defense and the military chain of command.
The UCMJ Attaches
Federalized Guard members fall under the Uniform Code of Military Justice, the same military criminal code that governs active-duty soldiers.8Office of the Law Revision Counsel. 10 USC 802 – Art. 2. Persons Subject to This Chapter A Guard member who refuses to report or leaves a federal assignment can be court-martialed. Unauthorized absence is punishable at the discretion of the court-martial, and desertion during wartime can carry the death penalty; peacetime desertion carries lesser punishment set by the court.9Office of the Law Revision Counsel. 10 USC 885 – Art. 85. Desertion The UCMJ applies from the moment the federalization order takes effect until the member returns to state control.
The Posse Comitatus Act Attaches Too
The Posse Comitatus Act, 18 U.S.C. § 1385, makes it a federal crime to use the Army, Navy, Marine Corps, Air Force, or Space Force to enforce civilian law unless Congress has expressly authorized it.10Office of the Law Revision Counsel. 18 USC 1385 – Use of Army, Navy, Marine Corps, Air Force, and Space Force as Posse Comitatus Title 32 Guard members are not covered because they are state forces, which is why governors can use them for law enforcement during natural disasters and civil disturbances. The moment those same troops federalize, the restriction attaches.
That produces a real constraint. Federalization gives the President command of the troops but simultaneously bars them from most law enforcement work unless a statutory exception applies. The main exception is the Insurrection Act itself. Without it, federalized Guard units are limited to support functions that do not involve directly enforcing civil law, such as logistics, communications, or perimeter security.
Can a Governor Refuse the Call-Up?
No. The Supreme Court held in Perpich v. Department of Defense (1990) that Congress can authorize federal call-up of Guard members without the governor’s consent, and that the Constitution does not give governors a veto over federal use of militia forces. The Court upheld the Montgomery Amendment, which eliminated a governor’s ability to withhold consent based on objections to the mission’s location, purpose, or schedule.
Governors are not without options, though. A governor can sue, arguing that the statutory triggers were not met or that the President exceeded the scope of the authorizing statute. That is what happened in California in 2025. The question in such a suit is not whether the governor can veto the order; it is whether the President properly invoked the statute.
How Long Federal Service Lasts
Guard members called under § 12406 serve for the period the President specifies, and the President can release them earlier if the situation resolves. One hard ceiling applies: no Guard member can be kept in federal service beyond the expiration of their enlistment or commission.11Office of the Law Revision Counsel. 10 US Code 12407 – National Guard in Federal Service: Period of Service; Apportionment
Section 12406 is not bound by the time limits that apply to other reserve mobilization authorities. Under 10 U.S.C. § 12302, for example, a service secretary can involuntarily activate Ready Reserve members for up to 24 consecutive months during a declared national emergency.12Office of the Law Revision Counsel. 10 USC 12302 – Ready Reserve A § 12406 call operates under its own framework tied to the President’s assessment of the emergency, not those caps.
Pay and Healthcare During Federal Service
Federalized Guard members receive the same pay and allowances as active-duty counterparts, including Basic Allowance for Housing calculated on duty station, rank, and dependency status. Members activated for fewer than 30 days receive a flat non-locality housing rate instead of the location-adjusted amount.13Defense Travel Management Office. Basic Allowance for Housing
TRICARE coverage can begin before the member reports. Guard members with delayed-effective-date orders for more than 30 days in support of a federal mission become eligible for TRICARE up to 180 days before activation.14TRICARE. TRICARE Benefits/Programs for the National Guard and Reserve During Early Eligibility and Activation During federal service, the member pays no enrollment fees, deductibles, or cost-shares under TRICARE Prime. Family members enroll automatically in TRICARE Prime where it is available, or TRICARE Select where it is not. For families of Guard members activated more than 30 days in support of a contingency operation, the yearly deductible under TRICARE Select is waived.
Civilian Job Protections
The Uniformed Services Employment and Reemployment Rights Act protects Guard members who leave civilian jobs for federal service. USERRA guarantees the right to return to your civilian position after military service, provided you gave your employer advance notice, your cumulative military absences with that employer do not exceed five years, and you report back within the required timeframe.15Office of the Law Revision Counsel. 38 USC 4312 – Reemployment Rights of Persons Who Serve in the Uniformed Services
Reporting deadlines depend on how long the federal service lasted:
- Service of 30 days or less: report by the start of your next regularly scheduled work period after traveling home and getting eight hours of rest.
- Service of 31 to 180 days: submit a reemployment application within 14 days of completing service.
- Service of more than 180 days: submit a reemployment application within 90 days.
Missing a deadline does not automatically forfeit reemployment rights. The employer can instead treat the absence under its standard policies for unexcused time off.16U.S. Department of Labor. USERRA Pocket Guide Members hospitalized or recovering from service-connected injuries get an extension of up to two years beyond the normal deadlines.
Interest Rate Protection on Pre-Service Debts
The Servicemembers Civil Relief Act caps interest at 6% per year on most debts a Guard member took on before entering federal service, including mortgages, car loans, credit cards, and student loans. The lender must forgive any interest above 6% and reduce the monthly payment accordingly, without accelerating the principal.17Office of the Law Revision Counsel. 50 USC 3937 – Maximum Rate of Interest on Debts Incurred Before Military Service
The cap runs for the duration of federal service and, for mortgages, extends one year afterward. To claim it, the Guard member must give the creditor written notice with a copy of the military orders no later than 180 days after service concludes.18U.S. Department of Justice. Your Rights as a Servicemember: 6% Interest Rate Cap for Servicemembers on Pre-Service Debts The protection reaches debts held jointly with a spouse when both names are on the account. Miss the 180-day window and you lose the ability to claim retroactive interest relief, so file early.