Age Requirements:
18 vs. 21 for Firearm Purchases

Illinois uses a two-tier age system for firearm ownership that is rooted in the FOID Act (430 ILCS 65). The FOID Act distinguishes applicants under 21 from those aged 21 or older and imposes additional requirements on younger applicants. Understanding these thresholds is critical for anyone purchasing a firearm in the state.^[1]

21 and Older: Standard FOID Eligibility

Any Illinois resident who is at least 21 years old may apply for a Firearm Owners Identification (FOID) card on their own, provided they meet all other eligibility criteria. These criteria include having no felony convictions, no domestic violence convictions, no existing orders of protection prohibiting firearm possession, no convictions in the past five years for battery, assault, aggravated assault, or violation of an order of protection in which a firearm was used or possessed (430 ILCS 65/8(k)), no involuntary admission to a mental health facility, and no adjudication as a person with a mental disability. A 21-year-old applicant does not need parental consent or sponsorship of any kind.^[2]

FOID Eligibility at Ages 18 to 20

Persons between 18 and 20 years old who meet the other FOID eligibility requirements may obtain a card with written consent from a parent or legal guardian, or through the exception for active-duty members of the United States Armed Forces or the Illinois National Guard who submit proof of service to the ISP annually. The sponsoring parent or guardian must qualify for a FOID card, meaning they must not be disqualified from firearm possession under state or federal law. The statute does not require the parent to hold a FOID card of their own (430 ILCS 65/4(a)(2)(i-5)). The consenting parent or legal guardian is liable for damages resulting from the applicant's use of firearms or firearm ammunition. If the parent's or guardian's FOID card is later revoked, the sponsored minor's FOID card is also subject to revocation.^[3]

In Illinois, the parent must complete and submit documentation to the ISP, creating a formal record of sponsorship that ties the minor's FOID eligibility directly to the parent's own legal status.

Under 18: Sponsored FOID Eligibility

The FOID Act sets no minimum age. A person under 18 who meets the other eligibility requirements may obtain a FOID card with written consent from a parent or legal guardian who is not prohibited from having a FOID card and files an affidavit stating that eligibility. A person must have a FOID card to possess a firearm or ammunition in Illinois unless a statutory exemption applies. FOID exemptions include unemancipated minors in the custody and immediate control of a parent, legal guardian, or person in loco parentis who holds a valid FOID card. They also include otherwise FOID-eligible people directly supervised by a FOID holder aged 21 or older at a shooting range or in a recognized firearms safety and training course, and properly authorized resident hunters accompanied by a FOID holder at a licensed commercial hunting club. These exemptions do not permit independent possession.^[4]

Federal Age Overlay

On September 17, 2026, DOJ's Office of Legal Counsel concluded that the federal handgun-sale restrictions in 18 U.S.C. 922(b)(1) and (c)(1) are unconstitutional as applied to otherwise law-abiding adults aged 18 to 20. This is an executive-branch legal opinion. It does not amend Illinois law or establish how an Illinois dealer currently processes a purchase. Read the OLC opinion.

Concealed Carry: 21 Only

The Firearm Concealed Carry Act (430 ILCS 66) sets an absolute minimum age of 21 for a Concealed Carry License. There is no parental consent exception for concealed carry. A person between 18 and 20 may possess a firearm at home or transport it in compliance with state law, but they cannot carry a concealed firearm on their person in public unless a statutory exception applies.^[5]

Practical Impact for Young Buyers

The combined effect of state and federal age requirements creates a tiered system. An 18-year-old Illinoisan with parental consent who meets the other eligibility requirements can obtain a FOID card and purchase lawful long guns from a dealer or lawful firearms through a private sale (with FOID verification), subject to Illinois restrictions on assault weapon and .50 caliber rifle purchases. A 21-year-old can apply independently for a FOID card, purchase lawful firearms from a dealer, and apply for a concealed carry license, subject to Illinois restrictions on assault weapon and .50 caliber rifle purchases. The September 17, 2026 OLC opinion changes the federal executive branch's legal position on dealer handgun sales to adults aged 18 to 20. Illinois eligibility requirements and dealer implementation need to be checked separately.

See also: FOID Automatic Renewal and Fingerprint Submission

See also: Universal Background Checks for Private Sales