Though more than 90% of the American public supports background checks for all gun sales, a dangerous and deadly loophole in federal gun laws still exempts unlicensed sellers from having to perform any background check whatsoever before selling a firearm. With this loophole, guns easily find their way into the hands of illegal buyers and gun traffickers, dramatically increasing the likelihood of gun murders and suicides.


By far the most dangerous gap in federal firearms laws today is the background check loophole. Although federal law requires licensed firearms dealers to perform background checks on prospective purchasers, it does not require unlicensed sellers to do so. A 2017 study estimated that 22% of US gun owners acquired their most recent firearm without a background check.1 Recent efforts to strengthen background check laws at the state level have had an impact—firearm owners who acquired their most recent firearm in the last two years were much more likely to have undergone a background check than those who acquired guns in previous years—but nearly one-quarter of gun owners who  obtained a firearm in the last two years did so without a background check.2 In states that do not require background checks on gun sales by unlicensed sellers, the numbers are far higher.3

According to the US Department of Justice, because federal law fails to require background checks by every person who sells or transfers a gun—known as universal background checks—“individuals prohibited by law from possessing guns can easily obtain them from private sellers and do so without any federal records of the transactions.4 “The private-party gun market,” one study observed, “has long been recognized as a leading source of guns used in crimes.”5 Although this loophole is sometimes referred to as the “gun show” loophole, because of the particular problems associated with unlicensed sellers at gun shows, it applies to all private firearm sales, regardless of where they occur.6

The internet has significantly increased illegal buyers’ ability to find sellers willing to transfer firearms to them without background checks.

  • As of September 2013, about 67,000 firearms were listed for sale online from private, unlicensed sellers.7
  • 29% of ads by private sellers on (a popular website for firearm sales) were posted by high-volume private sellers who posted five or more ads over an eight-week period.8
  • According to an undercover investigation by the City of New York, 62% of private online firearm sellers agreed to sell a firearm to a buyer even after the buyer had told the seller that he or she probably could not pass a background check.9

When unlicensed sellers don’t run background checks, people known to be dangerous can easily obtain guns, often with deadly consequences. For example, in 2012, a gunman killed three people, including his wife, and injured four others at a spa in Wisconsin, after buying a gun through a private seller he found online. The shooter was prohibited from purchasing guns due to an active domestic violence restraining order against him, but was able to buy the gun anyway because the seller was not required to run a background check.10

In a 2007 report, the International Association of Chiefs of Police (IACP) stated that, because individuals who fail a background check can easily access firearms from unlicensed sellers, “Guns are far too easily acquired by prohibited possessors, and too often end up being used in gun crime and gun violence.”11 The IACP concluded that “Congress, as well as state, local, and tribal governments, should enact laws requiring that all gun sales and transfers proceed through” a federally licensed dealer.12

Gun offenders overwhelmingly obtain their guns through private sales. A survey of state prison inmates in 13 states who were convicted of gun offenses found that only 13% obtained the gun from a gun store or pawnshop where background checks are required.13 Nearly all (96%) of those inmates who were already prohibited from possessing a gun at the time of their crime obtained the firearm through an unlicensed private seller.14

When background checks are required, they are extremely effective at keeping guns out of the hands of dangerous, prohibited persons. Since the federal background check requirement was adopted in 1994, over 3 million people legally prohibited from possessing a gun—mainly convicted felons, domestic abusers, and the dangerously mentally ill—have been denied a firearm transfer or permit.15 In 2014 alone, 147,000 prohibited people were blocked from acquiring guns by NICS, the federal background check system.16

The Data Confirms that Universal Background Check Laws are Effective and Save Lives

From 2009 to 2012, states that required background checks on all handgun sales or permits had 35% fewer gun deaths per capita than states without that background check requirement.17

Researchers have also found that, after adjusting for population, states that require background checks on all handgun sales experience less than half as many mass shooting incidents (52% fewer) as states without that background check requirement.18 States with background checks have 63% fewer mass shootings by individuals who are prohibited from possessing guns and 64% fewer mass shootings involving domestic violence.19 States with comprehensive background check laws also experience 48% less gun trafficking, 38% fewer deaths of women shot by intimate partners, and 17% fewer firearms involved in aggravated assaults, per capita.20

States with universal background check requirements also have 53% fewer firearm suicides and 31% fewer overall suicides per capita than states without these laws.21

One state has also provided a tragic case study in the importance of background checks in preventing gun violence and saving lives. In 2007, Missouri repealed its permit-to-purchase handgun licensing law, which had, since 1921, required all handgun purchasers to undergo a background check and obtain a license in order to lawfully purchase a handgun from any seller. This change eliminated mandatory background checks for handguns sold by private sellers in Missouri.

Johns Hopkins researchers determined that repeal of Missouri’s background check law was linked to a 14% increase in Missouri’s murder rate through 2012 and a 25% increase in firearm homicide rates.22 These researchers estimated that in tragic human terms, the law’s repeal translated into an additional 49 to 68 murders every year.23 This spike in murders in Missouri only occurred for murders committed with a firearm and was widespread across the state’s counties.24 In contrast, none of the states bordering Missouri experienced significant increases in their murder rates, and the national murder rate declined during this period by over 5%.25 Additionally, immediately following the repeal of Missouri’s background check law, there was a twofold increase in the percentage of guns recovered at Missouri crime scenes within two years of their retail sale.26 After the law was repealed, there was also a sharp increase in the percentage of crime guns recovered by police in Missouri that were originally purchased in that state.27 Other researchers confirmed that repeal of Missouri’s background check requirement was associated with a 16% increase in the state’s rate of firearm suicide.28

Another state offers a sharp contrast with Missouri. In 1995, Connecticut implemented a permit-to-purchase handgun licensing law that required applicants to pass a background check in order to purchase a handgun from any seller. Johns Hopkins Researchers found that Connecticut’s background check law was associated with a 40% reduction in the state’s firearm-related homicide rate.29 The large drop in homicides was found only in firearm-related killings, not in homicides by other means, confirming that this law drove the reduction in the state’s overall homicide rates.30 Other researchers also found that Connecticut’s background check laws was associated with a 15% reduction in firearm suicides.

Polls have repeatedly shown that the vast majority of the American public supports laws requiring background checks on all gun purchasers.31 A survey conducted for the New England Journal of Medicine in January 2013 found that 84% of gun owners and 74% of NRA members also support requiring a universal background check system for all gun sales.32

Summary of Federal Law

Federal law imposes various duties on federally licensed firearms dealers. Firearms dealers must, among other things:

  • Perform background checks on prospective firearm purchasers.
  • Maintain records of all gun sales.
  • Make those records available to law enforcement for inspection.
  • Report certain multiple sales.
  • Report the theft or loss of a firearm from the licensee’s inventory.33 Federal law imposes none of these requirements on unlicensed sellers, however.

The Gun Control Act of 1968 provides that persons “engaged in the business” of dealing in firearms must be licensed.34 Although Congress did not originally define the term “engaged in the business,” it did so in 1986 as part of the McClure-Volkmer Act (also known as the Firearms Owners’ Protection Act). That act defined the term “engaged in the business,” as applied to a firearms dealer, as “a person who devotes time, attention, and labor to dealing in firearms as a regular course of trade or business with the principal objective of livelihood and profit through the repetitive purchase and resale of firearms.”35

Significantly, however, the term was defined to exclude a person who “makes occasional sales, exchanges, or purchases of firearms for the enhancement of a personal collection or for a hobby, or who sells all or part of his personal collection of firearms.”36 According to a 1999 report issued by the Bureau of Alcohol, Tobacco, Firearms and Explosives, the current definition of “engaged in the business” often frustrates the prosecution of “unlicensed dealers masquerading as collectors or hobbyists but who are really trafficking firearms to felons or other prohibited persons.”37

Summary of State Law

Twenty states and Washington DC have extended the background check requirement beyond federal law to at least some private sales. 

Eleven states (California, Colorado, Connecticut, Delaware, Nevada, New Jersey, New York, Oregon, Rhode Island, Vermont, and Washington) and the District of Columbia require universal background checks at the point of sale for all sales and transfers of all classes of firearms, whether they are purchased from a licensed dealer or an unlicensed seller.38 (Note, however, that Nevada’s background check law, enacted through a voter ballot initiative in 2016, has not yet been implemented).39

Two more states, Maryland and Pennsylvania, require point of sale background checks for handguns but not for long guns, like rifles and shotguns.

Instead of a point of sale background check, three states (Hawaii, Illinois, and Massachusetts) require all firearm purchasers to obtain a permit, issued after a background check, in order to buy any firearm. New Jersey requires firearm purchasers to both obtain a permit to purchase a firearm and, if the purchase is from an unlicensed seller, conduct the transaction through a federally-licensed firearms dealer.40 Four more states (Iowa, Michigan, Nebraska, and North Carolina) have this permit and background check requirement for the purchase of handguns, but not long guns. Illinois also requires a point of sale background check whenever a firearm is sold at a gun show.

State Laws Closing the Private Sale Loophole

Background Checks at the Point of Transfer

The most comprehensive approach to ensuring that guns are not sold to prohibited people is through a requirement for a background check at the point of transfer of any firearm. Processing transfers by private sellers through licensed dealers or a law enforcement agency helps to ensure that a background check will be conducted prior to any transfer.

States that Require a Background Check at the Point of Transfer

District of Columbia45
Maryland (handguns and assault weapons only)46
Nevada (law not currently enforced)47
New Jersey48
New York49
Pennsylvania (handguns only)51
Rhode Island52

California, Colorado, Delaware, Nevada, New Jersey, New York, Oregon, Vermont, and Washington generally require all firearm transfers to be conducted by or processed through licensed dealers, who conduct background checks on prospective firearm purchasers or recipients. In the District of Columbia, firearms may be sold and transferred only by or to a licensed dealer.

Rhode Island requires all sellers to obtain a completed application form from the prospective purchaser and to submit the form to law enforcement for purposes of conducting a background check. Connecticut requires any person transferring a firearm to either submit a form to law enforcement or conduct the transfer through a licensed dealer, so that a background check is conducted for every sale or transfer.

Maryland and Pennsylvania require a background check for every prospective handgun sale or transfer, and provide that the background check may be conducted either by a licensed dealer or a designated law enforcement agency.

State Permit Requirements for Private Purchasers

Eight states implement firearm background check requirements on private sales primarily by prohibiting private sellers from transferring firearms to purchasers who do not have a requisite state license or permit, and by requiring a background check before issuing the license or permit.

States that Require Permits for Private Purchasers after Background Checks55

Iowa (handguns only)58
Michigan (handguns only)60
Nebraska (handguns only)61
New Jersey62
North Carolina (handguns only)63

Hawaii, Illinois, Massachusetts, and New Jersey require a person to obtain a license or permit before purchasing any firearm from any seller, and require applicants to pass a background check in order to obtain that license or permit. Iowa, Michigan, Nebraska, and North Carolina require a person to pass a background check in order to obtain a license or permit for the purchase of a handgun but not long guns like rifles or shotguns. State licensing requirements are discussed in detail in our policy page on Licensing. While these requirements ensure that a background check has been conducted at some point, a person may fall within a prohibited category after the license or permit is issued but before the time the person attempts to purchase a firearm. As a result, licensing laws do not necessarily prevent prohibited people from accessing firearms as effectively as point-of-transfer background checks.

Gun Show Background Checks

Illinois64 requires a background check before the sale or transfer of a firearm at a gun show. Additionally, though Oregon generally requires background checks to be conducted by a licensed dealer at the point of transfer for all firearms, Oregon law also allows a transferor at a gun show who is not a licensed dealer to contact the Department of State Police directly to conduct the background check.65 For more information about the regulation of gun shows, see our summary on Gun Shows.

In 2016, Virginia enacted a law requiring the state police to be available at gun shows in order to facilitate voluntary background checks requested by either party to a transaction if the seller is unlicensed.66

Key Legislative Elements

The features listed below are intended to provide a framework from which policy options may be considered. Any jurisdiction considering new legislation should consult with counsel.

  • For all firearm transfers, private sellers are subject to similar requirements as licensed dealers, including background checks and record-keeping requirements.
  • The most comprehensive policy option requires all firearm transfers to be conducted through licensed dealers, so that background checks will be completed on all purchasers (including purchases from unlicensed sellers), and sales records will be maintained (see California, Colorado, Delaware, District of Columbia, New York, Oregon, Vermont, and Washington).
  • If the jurisdiction does not require that all firearm transfers be conducted through licensed dealers, private sellers should be required to:
    • Conduct background checks through a central law enforcement agency that has access to federal and state databases of prohibited purchasers (Rhode Island requires private sellers to conduct background checks directly through law enforcement; Connecticut requires private sellers to conduct background checks through licensed dealers or law enforcement).
    • Maintain records of all firearm transfers for a lengthy period (Illinois requires all sellers to retain sales records for 10 years).
    • Report all transfers to state and local law enforcement (see Connecticut, Hawaii, Massachusetts).
  1. M. Miller, L. Hepburn, & D. Azrael . “Firearm Acquisition Without Background Checks”. Annals of Internal Medicine 166(4) (2017): 233-239. ⤴︎
  2. Id. ⤴︎
  3. Id. ⤴︎
  4. U.S. Dep’t of Justice, Office of the Inspector General, Review of ATF’s Project Gunrunner 10 (Nov. 2010), at In addition, because federal law does not require private sellers to inspect a buyer’s driver’s license or any other identification, there is no obligation for such sellers to confirm that a buyer is of legal age to purchase a firearm. ⤴︎
  5. Garen J. Wintemute et al., “Private-Party Gun Sales, Regulation, and Public Safety, New Eng. J. Med.363 (Aug. 5, 2010): 508, 509, at ⤴︎
  6. Issues specific to gun shows are discussed in our summary on Gun Shows. ⤴︎
  7. Third Way and Americans for Responsible Solutions, What a Difference a Law Makes: Online Gun Sales in States With and Without Background Checks (Sept. 2013), at ⤴︎
  8. Mayors Against Illegal Guns, In the Business, Outside the Law: How Unlicensed Sellers Are Flooding the Internet with Guns (Dec. 2013), at ⤴︎
  9. City of New York, Point, Click, Fire: An Investigation of Illegal, Online Gun Sales (Dec. 2011), at ⤴︎
  10. Michael Cooper, Michael S. Schmidt & Michael Luo, Loopholes in Gun Laws Allow Buyers to Skirt Checks, N.Y. Times (Apr. 10, 2013), at ⤴︎
  11. Int’l Ass’n of Chiefs of Police (IACP), Taking a Stand: Reducing Gun Violence in Our Communities 14 (2007), at ⤴︎
  12. Id. ⤴︎
  13. Katherine Vittes et al., “Legal status and source of offenders’ firearms in states with the least stringent criteria for gun ownership” 19 Injury Prev. (2013): 26-31. ⤴︎
  14. Id. ⤴︎
  15. Jennifer Karberg et al., “Background Checks for Firearm Transfers, 2013-14—Statistical Tables,” US Department of Justice: Bureau of Justice Statistics, (June 2016), ⤴︎
  16. Id. States may choose to have the FBI conduct background checks for guns sold in their state directly or to have a state agency process the background checks and contact the FBI on behalf of the seller. These statistics do not include background checks conducted for firearm licenses or permits. Id. ⤴︎
  17. Based on data from the Nat’l Ctr. for Injury Prevention & Control, U.S. Centers for Disease Control and Prevention, Web-Based Injury Statistics Query & Reporting System (WISQARS), Fatal Injury Reports, 1999-2014, for National, Regional, and States (accessed on Jun. 2, 2015), at The 15 states with the background check law over this period had a firearm fatality rate of 7.98 per 100,000 residents, while the other 35 states had a firearm fatality rate of 12.23 per 100,000. ⤴︎
  18. See Everytown for Gun Safety, Mass Shootings Analysis, Appendix 1 (Aug. 20, 2015), available at ⤴︎
  19. Everytown for Gun Safety, State Background Check Requirements: Mass Shootings (Nov. 12, 2015), ⤴︎
  20. See Igor Volsky, This New Study Proves That Background Checks Save Lives, Think Progress (Feb. 15, 2014), ⤴︎
  21. Michael D. Anestis, et al, “Suicide Rates and State Laws Regulating Access and Exposure to Handguns,” American Journal of Public Health 105, no. 10, e1, e3 (2015). ⤴︎
  22. Daniel Webster, Cassandra Kercher Crifasi, and Jon S. Vernick, “Erratum to: Effects of the Repeal of Missouri’s Handgun Purchaser Licensing Law on Homicides, Journal of Urban Health 3, (June 2014): 91. ⤴︎
  23. Id. ⤴︎
  24. Id. ⤴︎
  25. Id. ⤴︎
  26. Id. ⤴︎
  27. Id. ⤴︎
  28. CK Crifasi, et al, “Effects of Changes in Permit-to-Purchase Handgun Laws in Connecticut and Missouri on Suicide Rates, Prev. Med. (2015). ⤴︎
  29. Kara E. Rudolph, et al, “Association Between Connecticut’s Permit-to-Purchase Handgun Law and Homicides,” Am. J of Pub. Health (Jun. 2015). ⤴︎
  30. CK Crifasi, et al, “Effects of Changes in Permit-to-Purchase Handgun Laws in Connecticut and Missouri on Suicide Rates,” Prev. Med. (2015). ⤴︎
  31. CNN/ORC International poll (Aug. 9, 2012), at (finding that 96% of respondents supported universal background checks); Sarah Dutton et al., 9 in 10 Back Universal Gun Background Checks, (Jan. 17, 2013), at; Dana Blanton, Fox News poll: Twice as Many Favor More Guns over Banning Guns to Reduce Crime, (Jan. 18, 2013), at ⤴︎
  32. Colleen L. Barry et al., Perspective: After Newtown — Public Opinion on Gun Policy and Mental Illness,” New Eng. J. Med368 (March 21, 2013): 1077-1081, at ⤴︎
  33. 18 U.S.C. §§ 922(t), 923(g). ⤴︎
  34. 18 U.S.C § 921(a)(21)(C). ⤴︎
  35. Id. ⤴︎
  36. Id. ⤴︎
  37. U.S. Department of Justice & Bureau of Alcohol, Tobacco and Firearms, U.S. Department of the Treasury, Gun Shows: Brady Checks and Crime Gun Traces 13-14 (Jan. 1999). ⤴︎
  38. These states adopted their universal background check laws in this order: Washington D.C. (conducts universal background checks as part of a firearm registration law that was enacted in 1975), Rhode Island (1990), California (1991), New York (2013), Colorado (2013), Connecticut (2013), Delaware (2013), Washington (2014 by voter initiative), Oregon (2015), Nevada (2016), and Vermont (2018). ⤴︎
  39. Due to an ongoing dispute between the FBI and Nevada’s Attorney General about which law enforcement agency is responsible for processing background checks in that state, Nevada currently does not prosecute individuals for failing to conduct background checks on private sales of firearms. See Office of the Attorney General of the State of Nevada, Opinion No. 2016-12 on Nevada Revised Statute 228.150, Dec. 28, 2016, ⤴︎
  40. N.J. Stat. Ann. § 2C:58-3. ⤴︎
  41. Cal. Penal Code §§ 27545, 27850-28070. ⤴︎
  42. Colo. Rev. Stat. § 18-12-112; 2013 Colo. H.B. 1229. See also Colo. Rev. Stat. §§ 12-26.1-101 – 12-26.1-108. ⤴︎
  43. Conn. Gen. Stat. §§ 29-33(c), 29-36l(f), 29-37a(e)-(j). 2013 Ct. ALS 3. See also Conn. Gen. Stat. § 29-37g (pre-existing law requiring a background check before a firearm is sold at a gun show). ⤴︎
  44. Del. Code tit. 11, § 1448B, tit. 24, § 904A. ⤴︎
  45. D.C. Code Ann. § 7-2505.02. ⤴︎
  46. Md. Code Ann., Pub. Safety §§ 5-101(t), 5-124. Maryland’s requirement applies to “regulated firearms,” which is defined to include handguns and assault weapons. However, assault weapons are now generally banned in Maryland. ⤴︎
  47. In November 2016, Nevada voters approved a ballot initiative to require background checks on private sales of firearms. The New York Times, Nevada Question 1 — Expand Gun Background Checks — Results: Approved, Feb., 2017, at However, after the FBI announced that it would not conduct background checks in the manner the initiative required it to, the Nevada Attorney General issued an opinion stating that it would not enforce the initiative. Office of the Attorney General of the State of Nevada, Opinion No. 2016-12 on Nevada Revised Statute 228.150, Dec. 28, 2016, ⤴︎
  48. N.J. Stat. Ann. § 2C:58-3. ⤴︎
  49. N.Y. Gen. Bus. Law § 898. 2013 NY ALS 1. See also N.Y. Gen. Bus. Law §§ 895-897; N.Y. Penal Law § 400.00 (pre-existing law requiring a background check before sale of a firearm at a gun show). ⤴︎
  50. Or. Rev. Stat. § 166.435. At gun shows, Oregon law allows a transferor who is not a licensed dealer to contact the Department of State Police directly to conduct the background check. Or. Rev. Stat. § 166.436. ⤴︎
  51. 18 Pa. Cons. Stat. § 6111(b), (c), (f)(2). ⤴︎
  52. R.I. Gen. Laws §§ 11-47-35 – 11-47-35.2. ⤴︎
  53. Vt. Stat. Ann. tit. 13, § 4019, enacted by 2017 SB 55, Sec. 6. ⤴︎
  54. Rev. Code Wash. § 9.41.113. In 2014, Washington became the first state to enact a law requiring background checks on private sales by voter initiative. See Initiative Measure No. 594, available at ⤴︎
  55. This list excludes states, like Connecticut and New York, which require a background check at the point of sale in addition to a license or permit. ⤴︎
  56. Haw. Rev. Stat. Ann. §§ 134-2, 134-13. ⤴︎
  57. 430 Ill. Comp. Stat. 65/1 – 65/15a, 720 Ill. Comp. Stat. 5/24-3(k). Since 2014, Illinois has required a seller to contact law enforcement and verify the validity of the purchaser’s permit (called a FOID Card) at the time of the sale. ⤴︎
  58. Iowa Code §§ 724.15 – 724.20. ⤴︎
  59. Mass. Gen. Laws ch. 140, §§ 121, 129B, 129C, 131, 131A, 131E, 131P. ⤴︎
  60. Mich. Comp. Laws §§ 28.422, 28.422a. ⤴︎
  61. Neb. Rev. Stat. Ann. §§ 69-2404, 69-2407, 69-2409. ⤴︎
  62. N.J. Stat. Ann. § 2C:58-3. ⤴︎
  63. N.C. Gen. Stat. §§ 14-402 – 14-404. ⤴︎
  64. 430 Ill. Comp. Stat. 65/3, 65/3.1. ⤴︎
  65. Or. Rev. Stat. § 166.436. ⤴︎
  66. Va. Code Ann. § 54.1-4201.2 as amended by 2016 VA H 1386/S 715. ⤴︎