NICS & Brady Act — Federal Firearms Background Check System

The National Instant Criminal Background Check System (NICS) is the federal system used to determine whether a prospective firearms buyer is eligible to purchase a gun — or is a prohibited person barred by federal law from possessing firearms. Established by the Brady Handgun Violence Prevention Act of 1993 (Brady Act), NICS is operated by the FBI and processes approximately 28–40 million background checks per year (a record 38.9 million in 2023). When you buy a firearm from a federally licensed firearms dealer (FFL), you complete ATF Form 4473 and the dealer contacts NICS — either through the FBI's call center or through a state-operated point of contact system (19 states run their own checks). NICS searches three databases: the NICS Index (records specifically submitted for firearms eligibility), the National Crime Information Center (NCIC), and the Interstate Identification Index (III) — checking for disqualifying records including felony convictions, domestic violence misdemeanors, active restraining orders, involuntary mental health commitments, drug use, and other prohibiting factors listed in 18 U.S.C. § 922(g). Most checks are completed in seconds — approximately 90% result in an immediate "proceed" determination. If the check cannot be completed immediately, the dealer receives a "delayed" response and the FBI has 3 business days to make a determination. If the FBI doesn't respond within 3 business days, the dealer may proceed with the sale — the so-called "default proceed" or "Charleston loophole" (the 2015 Charleston church shooter obtained his firearm through a default proceed after the FBI failed to complete the check in time). The Bipartisan Safer Communities Act of 2022 expanded NICS checks for buyers under 21 and strengthened mental health record reporting.

Current Law (2026)

Parameter	Value
Governing statute	Brady Handgun Violence Prevention Act (34 U.S.C. §§ 40901–40913)
Operated by	FBI Criminal Justice Information Services (CJIS) Division
Annual checks	~28–40 million per year
Required for	All sales by federally licensed firearms dealers (FFLs)
Not required for	Private sales between individuals in most states (the "gun show loophole")
Response time	~90% instant; 3 business days for delayed checks; default proceed after 3 days
Prohibited persons	18 U.S.C. § 922(g) — felons, domestic violence misdemeanants, drug users, those involuntarily committed, fugitives, undocumented immigrants, and others
Under-21 enhancement	Bipartisan Safer Communities Act (2022) — expanded juvenile and mental health record review for buyers 18–20
Denials	~1.5% of checks result in denial; ~100,000 per year

Legal Authority

34 U.S.C. §§ 40901–40913 — National Instant Criminal Background Check System (NICS)
18 U.S.C. § 922(g) — Prohibited persons (categories of individuals barred from possessing firearms)
18 U.S.C. § 922(t) — Background check requirement for FFL transfers
Bipartisan Safer Communities Act of 2022 — Enhanced checks for under-21 buyers; strengthened mental health record reporting

How It Works

Federal law (18 U.S.C. § 922(g)) prohibits firearms possession by nine categories of prohibited persons: convicted felons (any crime punishable by more than one year); fugitives from justice; unlawful drug users or addicts; persons adjudicated as mental defective or involuntarily committed; undocumented immigrants and most nonimmigrant visa holders; persons dishonorably discharged from the military; persons who have renounced U.S. citizenship; persons subject to certain domestic violence restraining orders; and persons convicted of misdemeanor domestic violence crimes. The Supreme Court in United States v. Rahimi (2024) upheld the domestic violence restraining order prohibition under the Second Amendment. If NICS cannot complete a background check within 3 business days — typically because records are incomplete or a match requires investigation — the dealer may legally proceed with the sale. Approximately 3,000–4,000 firearms per year are transferred to prohibited persons through default proceeds; the FBI later refers discovered cases to ATF for retrieval. The 2015 Charleston church shooting — where the shooter obtained a firearm through a default proceed despite a disqualifying drug arrest record not yet retrieved — brought national attention to the gap. The Bipartisan Safer Communities Act did not close default proceeds but extended the check period to 10 business days for buyers under 21.

Federal law requires NICS checks only for sales through federally licensed dealers (FFLs) — not for private sales between individuals. A person can buy from a private seller at a gun show, through an online listing, or in any private transaction without a background check; approximately 22% of firearms acquisitions occur this way. Twenty-two states have enacted universal background check laws requiring private sales to go through an FFL for a NICS check; federal universal background check legislation has not passed. NICS is also only as good as its underlying records — many states fail to submit complete criminal histories, mental health adjudications, and domestic violence records. The NICS Improvement Amendments Act of 2007, enacted after the Virginia Tech shooting (where the shooter's mental health records weren't in NICS), incentivized states to improve reporting. The Fix NICS Act (2018) further strengthened requirements for federal agencies, but compliance remains uneven across states.

How It Affects You

If you're buying a firearm from a licensed dealer: You'll complete ATF Form 4473 and undergo a NICS check before receiving the firearm. Most checks are instant. If the system returns a "Delay" status, the dealer must wait up to 3 business days for a final determination — if no response comes within 3 business days, federal law allows (but doesn't require) the dealer to proceed with the sale. This is the "Charleston loophole" — the Dylan Roof case showed that this timing gap allowed a prohibited person to purchase a gun when the FBI didn't complete the check in time. If you're delayed, you can contact the FBI's NICS Section directly (877-444-6427) to get information on your delay. The form asks about 13 disqualifying conditions; answer accurately — false statements on Form 4473 are a federal felony (18 U.S.C. § 922(a)(6)).

If you've been denied a firearm purchase and believe it's in error: You can appeal a NICS denial through the FBI's NICS Appeal Process — request the denial reason through a Personal Identification Number (PIN) from the NICS customer service line (877-444-6427), review the record that caused the denial, and submit documentation correcting the error. Common causes of erroneous denials: similar names (misidentified as a prohibited person), expunged convictions that should be removed from records, or state records not updated after a conviction was dismissed. If a state agency's records caused the denial, contact that agency directly to correct the underlying record — the FBI can only work with what states report to NICS.

If you're a private seller: In most states, you are not legally required to run a NICS check on a private sale buyer — but you may not knowingly sell to a prohibited person (18 U.S.C. § 922(d)). If the buyer makes statements indicating they can't pass a background check, you cannot complete the sale. 22 states and D.C. have universal background check laws requiring all or most private sales to go through a licensed dealer for a NICS check; verify your state's requirements before completing any private sale. The "gun show loophole" refers to this federal gap — licensed dealers at gun shows must run checks; unlicensed private sellers at gun shows generally don't have to in states without universal check laws.

If you're a federal firearms licensee (FFL): You must conduct a NICS check on every transfer. You may not transfer a firearm to a person who receives a "denied" response — attempting to do so is a federal crime. After 3 business days without a determination, you may proceed with the sale, but you bear no civil liability if the buyer turns out to be prohibited if you acted in good faith. Maintain your ATF Form 4473s for at least 20 years — the ATF can inspect your records. Report multiple handgun sales (2+ pistols or revolvers in 5 consecutive business days to the same person) on ATF Form 3310.4; similar reporting applies to certain long-gun sales in border states.

State Variations

Background check requirements vary significantly by state:

Point of contact states (19): The state runs its own background check (using NICS and additional state databases) rather than going through the FBI directly
Universal background check states (22): Require NICS checks for all firearms sales, including private transactions
Waiting periods: Some states impose waiting periods (3–14 days) in addition to or instead of relying on the 3-day default proceed
Permit-to-purchase: Some states require a separate purchase permit (with its own background check) — this functions as an alternative or supplement to NICS
Enhanced mental health reporting: States vary dramatically in the completeness of mental health records submitted to NICS

Implementing Regulations

28 CFR Part 25 — National Instant Criminal Background Check System (NICS) Regulations (18 sections — the FBI's complete operational rules for the NICS, implementing the Brady Handgun Violence Prevention Act; authority: 34 U.S.C. §§ 40901–40913; 18 U.S.C. § 922):
- § 25.3 — System information: the NICS Index contains records submitted specifically for NICS purposes (mental health adjudications, drug addiction determinations, renunciations of citizenship, dishonorable discharges, domestic violence misdemeanor convictions, and immigration status); NICS also searches NCIC and the III for criminal history records and wanted persons
- § 25.4 — Record source categories: federal and state agencies are the primary NICS record submitters; mental health agencies and courts submit prohibitor records; submitting agencies are responsible for accuracy — the FBI does not independently verify submitted records
- § 25.6 — Transaction procedures: an FFL initiates a check by providing the buyer's name, date of birth, and Form 4473 information; the FBI (or state POC) returns one of three responses: "proceed" (no prohibiting records found), "delayed" (search ongoing), or "denied" (prohibited person identified); a "delayed" response not resolved within 3 business days (10 days for buyers under 21 under BSCA 2022) becomes a de facto "proceed" — the FFL may transfer the firearm, the "default proceed" or "Charleston loophole" provision
- § 25.9 — Retention: "proceed" records are destroyed within 24 hours under current FBI policy (following controversy over whether retained records constituted a de facto gun registry); "denied" and "delayed" records are retained longer for appeal and audit purposes
- § 25.10 — Correction of erroneous records: individuals wrongly denied may appeal through the FBI's NICS Appeals Unit; if the denial was based on erroneous state records, the FBI directs the individual to the state agency — the FBI does not correct state records unilaterally; some wrongful denials cannot be corrected at the federal level and require state court action
- § 25.11 — Prohibited activities: unauthorized access to NICS, providing false information on a transfer form (Form 4473), and accepting a firearm transfer knowing you are prohibited are federal violations; straw purchases (a non-prohibited person buying on behalf of a prohibited person) violate both Part 25 and 18 U.S.C. § 922(a)(6)
The default-proceed rule — when a check cannot be completed in 3 business days the FFL may transfer — is the most criticized element of Part 25. Congress intentionally designed it to prevent indefinite delays from blocking legitimate purchases, but the 2015 Charleston shooting demonstrated its risk: the shooter obtained a firearm through a default proceed despite a disqualifying drug arrest record not yet retrieved from a state system. Recent rulemakings: 89 FR 88501 (November 2024) — implemented BSCA 2022 requirement extending the default proceed window to 10 business days for buyers under 21.
27 CFR Part 478 — ATF Commerce in Firearms and Ammunition, setting requirements for federal firearms licensees (FFLs), including Form 4473 completion, record-keeping, and NICS check procedures for every firearm transfer
27 CFR Part 447 — ATF importation of arms, ammunition, and implements of war, governing the import eligibility determinations that feed into prohibited person assessments

Pending Legislation

Universal background check bills and NICS improvement legislation are introduced every Congress. See Gun Control & Second Amendment for related legislative activity in the 119th Congress.

Recent Developments

The Bipartisan Safer Communities Act of 2022 was the most significant federal gun safety legislation in nearly 30 years — expanding NICS checks for buyers under 21 (requiring review of juvenile and mental health records, with an extended 10-business-day investigation period), incentivizing state crisis intervention orders ("red flag" laws), strengthening penalties for straw purchases and firearms trafficking, and funding mental health and school safety programs. NICS processed a record 38.9 million checks in 2023, reflecting continued high firearms demand. United States v. Rahimi (2024) upheld the constitutionality of the domestic violence restraining order firearm prohibition — the first major post-Bruen decision applying the Supreme Court's new historical test to firearms regulations.

ATF ghost gun rule upheld; bump stock ban reversed (2024-2025): The Supreme Court's Bondi v. VanDerStok (decided March 26, 2025, 7-2, Gorsuch) upheld ATF's rule classifying ghost gun kits as "firearms" subject to NICS background check requirements — closing the loophole that had allowed ghost guns to be sold without checks. Garland v. Cargill (June 14, 2024) reversed the ATF bump stock ban, finding bump stocks don't convert semi-automatic rifles into machine guns under the statutory definition. Trump's ATF further rescinded the pistol brace rule (which had classified many pistol-brace-equipped guns as short-barreled rifles) via executive order and Congressional Review Act resolution.
NICS mental health record gap: Despite the Bipartisan Safer Communities Act's improvements, NICS records remain incomplete in many states. The FBI's NICS database depends on states voluntarily submitting mental health disqualifiers, domestic violence records, and other prohibitor information. States vary enormously in completeness — some have submitted millions of records, others have submitted nearly none. The Virginia Tech, Aurora, and Sutherland Springs shootings all involved failures to submit disqualifying records to NICS. The BSCA included new funding to improve state record submission; progress has been uneven.
Universal background check legislation stalled: Universal background check bills — requiring NICS checks for private transfers, not just licensed dealer sales — have passed the House in each of the last three Congresses but have not advanced in the Senate due to the 60-vote threshold. An estimated 22% of gun transfers occur without background checks through private sales, online platforms, and gun shows (in states without universal check laws). The gun show "loophole" (no federal requirement for private sellers at gun shows to use NICS) remains intact under federal law.
Post-Bruen constitutional landscape (2025-2026): Following New York State Rifle & Pistol Assn. v. Bruen (2022), federal courts have applied the "historical tradition" test to firearm regulations — striking down some prohibitions (certain felon-in-possession provisions, some drug user prohibitions) while upholding others (Rahimi, domestic violence restraining orders). The Biden-era ATF regulations have been challenged and partly invalidated under Bruen. The evolving case law makes it difficult to predict which background check requirements — particularly for marijuana users, some non-violent felons, and individuals under civil commitment — will survive constitutional scrutiny.