Age Retirement Annuity
A member is eligible to receive a monthly retirement annuity when he or she terminates active service covered by TRS and meets the following age and service requirements:
• age 62 with 5 years of service, or
• age 60 with 10 years of service, or
• age 55 with 20 years of service (discounted annuity), or
• age 55 with 35 years of service.*
* If the member is eligible to receive a retirement benefit of at least 74.6 percent of the final average salary and will reach age 55 between July 1 and December 31, he or she will be considered to have attained age 55 on the preceding June 1.
The retirement benefit is calculated by applying a statutory formula based on average salary and years of service. The salary used in the calculation is the average of the creditable earnings in the highest four consecutive years within the last 10 years of creditable service. For post-June 1998 service, this average salary is multiplied by 2.2 percent for each year of service.
For service earned before July 1998 that is not upgraded (see below), the average salary is multiplied by the applicable percentage according to the following formula:
1.67% for each of the first 10 years, plus
1.90% for each of the second 10 years, plus
2.10% for each of the third 10 years, plus
2.30% for each year over 30.
Source Illinois Government.