This is also called a Section 218 Agreement
In 1951, states could first voluntarily elect Social Security coverage for their public employees if not already covered under a retirement system. This was done with the Social Security Administration and known as a Section 218 Agreement or the Federal-State Agreement. Beginning in 1955, employees already under a public retirement system could additionally be covered under Social Security.
April 20, 1983. Prior to this date, states were permitted to terminate the coverage of any or all groups of employees listed in the state’s agreement. Since April 20, 1983, coverage under the Federal-State Agreement cannot be terminated (unless the entity is legally dissolved). Therefore, if a public employee is covered under a Federal-State Agreement and later joins a public retirement system, Social Security coverage under the agreement must continue.
April 1, 1986. All public employees hired after March 31,1986, must be covered for Medicare HI-only unless specifically excluded by law . Employees covered by Social Security must also be covered by Medicare.
To determine if your Colorado Public Employer currently has an active Plan and Agreement (Section 218 Agreement) or if your Public Employer was subject to an Agreement that is now inactive according to State records, enter the name of your Public Employer in the field below.