| Keystone Bank | Alabama |
| Keystone Credit Union | Texas |
| Keystone Federal Credit Union Merged | Pennsylvania |
| Keystone Savings Bank | Iowa |
| Keystone United Methodist Federal Credit Union | Pennsylvania |
| KeyWorth Bank | Georgia |
| KGC Federal Credit Union | Pennsylvania |
| KH Network Credit Union | Ohio |
| Kief Protective Mutual Benefit Association Credit Union | Connecticut |
| Kilgore National Bank | Texas |
| Kilgore Shell Employees Federal Credit Union | Texas |
| Kilowatt Community Credit Union | Missouri |
| Kimberly Clark Credit Union | Tennessee |
| Kimcentral Credit Union | Wisconsin |
| Kindred State Bank | North Dakota |
| Kinecta Federal Credit Union | California |
| Kinetic Federal Credit Union | Georgia |
| Kings Federal Credit Union | California |
| Kingsley State Bank | Iowa |
| King Southern Bank | Kentucky |
| Kings Peak Credit Union | Utah |
| Kingsport Press Credit Union | Tennessee |
| Kingston National Bank | Ohio |
| Kingston TVA Employees Credit Union | Tennessee |
| Kingstree Federal Savings and Loan Association | South Carolina |
| Kingsville Area Educators Federal Credit Union | Texas |
| Kirkpatrick Bank | Oklahoma |
| Kirkwood Bank of Nevada | Nevada |
| Kirkwood Bank & Trust Co. | North Dakota |
| Kirtland Federal Credit Union | New Mexico |
| Kish Bank | Pennsylvania |
| Kiski Area School Employees Federal Credit Union | Pennsylvania |
| KIT Federal Credit Union | Kentucky |
| Kitsap Bank | Washington |
| Kitsap Credit Union | Washington |
| Kit Tel Federal Credit Union | Pennsylvania |
| Klamath Public Employees Federal Credit Union | Oregon |
| Kleberg Bank | Texas |
| KleinBank | Minnesota |
| Knoll Employees Credit Union | Pennsylvania |
| Knox County Employees Credit Union | Tennessee |
| Knox County Teachers Federal Credit Union | Tennessee |
| Knoxville Firefighters Federal Credit Union | Tennessee |
| Knoxville Law Enforcement Federal Credit Union | Tennessee |
| Knoxville News-Sentinel Employees Credit Union | Tennessee |
| Knoxville Teachers Federal Credit Union | Tennessee |
| Knoxville TVA Employees Credit Union | Tennessee |
| KodaBank | North Dakota |
| Kohler Credit Union | Wisconsin |
| Kokomo Heritage Federal Credit Union | Indiana |
| Kolmar NY Employees Federal Credit Union | New York |
| Kone Employees Credit Union | Illinois |
| Kootenai Valley Federal Credit Union | Montana |
| Kopernik Bank | Maryland |
| Korean American Catholics Federal Credit Union | New York |
| Korean Catholic Federal Credit Union | Maryland |
| Kosciuszko Federal Savings Bank | Maryland |
| Kraftcor Federal Credit Union | Kentucky |
| Kraftman Federal Credit Union | Louisiana |
| Kraftsman Federal Credit Union | Virginia |
| Kraton Belpre Federal Credit Union | Ohio |
| KRD Federal Credit Union | Nebraska |
| Kress National Bank | Texas |
| KS Bank | North Carolina |
| KS StateBank | Kansas |
| KSW Federal Credit Union | Maine |
| Kuakini Medical and Dental Federal Credit Union | Hawaii |
| KUE Federal Credit Union | Kentucky |
| KUMC Credit Union | Kansas |
| KV Federal Credit Union | Maine |
| Kyang Federal Credit Union | Kentucky |