| January 1943 | Fairfax County Policemen’s Pension and Retirement Board established | Police |
| March 1944 | The General Assembly of Virginia adopts the Police Retirement Act, which empowered the County to establish the 5 member “Policemen’s Pension and Retirement Board” – now called the Police Officers Retirement System (PORS) | Police |
| July 1955 | First meeting of 5-member SRS Board of Trustees | Employees' |
| July 1955 | Supplemental Retirement System (SRS) established (Employee contributions are set at 4% of salary with a 1.5% multiplier) | Employees' |
| May 1967 | First full-time employee hired to support the retirement systems - Millie Vella | Employees',Police |
| September 1967 | School Food Service employees added into SRS | Employees' |
| September 1968 | School Bus Drivers added into the SRS | Employees' |
| July 1969 | Park Authority employees added into the SRS | Employees' |
| May 1974 | SRS ordinance changed to include a pre-62 benefit | Employees' |
| May 1974 | Establishment of Uniformed Retirement System (URS) | Uniformed |
| July 1974 | Firemen, Sheriff’s Deputies, Park Police, and Game Wardens moved from SRS into URS | Uniformed,Employees' |
| November 1974 | First meeting of 6-member URS Board of Trustees | Uniformed |
| April 1975 | Retirement office moved to the 3rd Floor of the Massey Building | Uniformed,Police,Employees' |
| April 1977 | Crossing Guards added into the SRS | Employees' |
| April 1977 | Retirement office moved to 4101 Chain Bridge Road in Fairfax City | Uniformed,Police,Employees' |
| September 1978 | Retirement office moved to 4020 University Drive in Fairfax City | Uniformed,Police,Employees' |
| July 1981 | SRS Multiplier increased from 1.5 to 1.8% & increased pre-62 benefit to 1% of AFC | Employees' |
| July 1981 | Plan B established for URS | Uniformed |
| July 1981 | Plan B established for SRS (Employees contributes 5.33% with a multiplier of 2.0%) | Employees' |
| July 1981 | Several Police benefit changes implemented | Police |
| July 1981 | Several Uniformed benefit changes implemented | Uniformed |
| July 1985 | Economic development employees came in the SRS system (new with no previous service granted) | Employees' |
| August 1987 | All 3 systems Mandatory retirement at age 70 eliminated, eliminate age 70 age limit on eligibility for service-connected disability retirement | Uniformed,Police,Employees' |
| August 1987 | Health Insurance subsidy established at $30 per month, beginning at age 62 | Employees' |
| July 1988 | Sick leave begins to be used in calculation of final average salary | Uniformed,Police,Employees' |
| June 1989 | Establishment of Retirement Administration Agency | Employees',Police,Uniformed |
| September 1989 | Retirement benefits become taxable by state of Virginia effective tax year 1989 | Uniformed,Police,Employees' |
| July 1990 | Health Insurance subsidy increased from $30 to $45 | Uniformed,Police,Employees' |
| May 1993 | Exclusion of Overtime from Creditable Compensation | Employees' |
| October 1993 | Retirement office moved to 10680 Main Street in Fairfax City | Uniformed,Police,Employees' |
| July 1995 | Additional 3% benefit increase added for all systems, to compensate for State taxation of benefits | Uniformed,Police,Employees' |
| July 1996 | Major changes to Uniformed disability benefits go into effect | Uniformed |
| July 1997 | Portability of Pension Benefits Within the Commonwealth of Virginia. | Employees',Police,Uniformed |
| July 1998 | Health subsidy raised to $60 from $45 for age 62 and older | Uniformed,Police,Employees' |
| February 2000 | Uniformed multiplier went from 1.8 to 2.0A & B and from 2.3 to 2.5C & D | Uniformed |
| February 2000 | Police benefit multiplier increased from 2.5 to 2.8 | Police |
| July 2000 | Pre 62 Benefit becomes pre-social security benefit | Employees' |
| July 2000 | Health insurance subsidy increases from $60 to $100 and | Uniformed,Police,Employees' |
| January 2001 | Uniformed elimination of SS offset due to unrelated disability regarding disability benefits from County | Uniformed |
| February 2001 | Supplemental System (SRS) name changed to Employees’ Retirement System (ERS) | Employees' |
| February 2001 | Reducing the Offset for Service-Connected Disability Retirement Allowance for Social Security Disability Benefits. | Uniformed |
| March 2002 | Changing Method for Determining the Annual Employer Contribution Rate in Retirement Systems | Police,Uniformed,Employees' |
| October 2003 | Deferred Retirement Option Program (DROP) implemented for Police & Uniformed Systems | Uniformed,Police |
| March 2005 | New Ordinance language on reemployed annuitants all 3 systems max of 115% county ex of salary and retirement | Uniformed,Police,Employees' |
| March 2005 | Changes Regarding the Maximum Combined Compensation for a Rehired Retiree | Employees',Police,Uniformed |
| July 2005 | DROP Implemented for members of Employees’ System | Employees' |
| July 2005 | Public Safety Communications new hires are enrolled in Uniformed | Uniformed |
| October 2005 | Public Safety Communications transfers allowed - move from Employees to Uniformed - must make election on or before September 1, 2005 | Uniformed,Employees' |
| January 2007 | Completed implementation of Pension Gold software for administration of benefit payments, actuarial data tracking, and counseling activities | Uniformed,Police,Employees' |
| June 2007 | Reduce Social Security Offset to Service-Connected Disability Benefits (64% to 40%) | Employees',Uniformed |
| July 2007 | Police 84% cap (30 years) on benefits REMOVED there is no longer a maximum | Police |
| July 2007 | Police Contribution Rate lowered to 11% from 12% | Police |
| April 2008 | Unveiled new Retirement Systems website, redesigned in Web Content Management (WCM) | Uniformed,Police,Employees' |
| June 2008 | Reduce Social Security Offset to Service-Connected Disability Benefits (40% to 30%) | Employees',Uniformed |
| July 2008 | Unveiled Web Member Services (WMS) PensionGold online access software | Uniformed,Police,Employees' |
| July 2008 | Police Member contribution rate lowered from 11% to 10% | Police |
| October 2010 | DROP Sunset Provision eliminated for all 3 systems | Uniformed,Police,Employees' |
| July 2011 | Reduce Social Security Offset to Service-Connected Disability Benefits (30% to 25%) | Employees',Uniformed |
| January 2013 | New Retirement Plans for ALL new hires on and after January 1, 2013 * ERS Plans C & D, Rule of 85, earliest normal age 55 * PORS Plan B * URS Plan E | Uniformed,Police,Employees' |
| November 2013 | Reduce Social Security Offset to Service-Connected Disability Retirement (25% to 15%) | Employees',Uniformed |
| July 2014 | Police Member contribution rate decreased from 10% to 8.65% | Police |
| January 2015 | All 3 Systems' County Codes were made more stylistically consistent, logically organized and freed of provisions no longer serving a useful purpose | Uniformed,Police,Employees' |
| June 2015 | Changes in the County’s funding policy | Uniformed,Police,Employees' |
| July 2016 | Reduce social security offset for disability from 15% to 10% | Uniformed,Employees' |
| July 2017 | Reduce social security offset for disability from 10% to 5% | Uniformed,Employees' |
| September 2017 | Retirement office moved to 1215 Lee Jackson Memorial Highway | Uniformed,Police,Employees' |
| July 2018 | Eliminate social security offset for disability retirees | Uniformed,Employees' |
| November 2018 | New plans established for new employees hired on or after July 1, 2019 | Uniformed,Police,Employees' |
| June 2019 | Police Spousal Option Changes | Police |
| February 2020 | Changes to severe service-connected disability criteria - respiratory exposure | Uniformed |
| July 2020 | Police buy in and additional Board member | Police |
| May 2024 | Military Service Credit Purchases Made Available to URS and PORS members | Police,Uniformed |
| April 2025 | Animal Protection Police Of Transition Retirement Options | Uniformed,Police,Employees' |
