There are four different retirement schemes used for active duty US Service Members.

Name of Retirement Plan:
- Final Pay
- Hight-36
- CBS/REDUX
- BRS (Blended Retirement System)

1) Final Pay:

Details: Defined Benefit that equals 2.5% times the number of years of service times the member’s final basic pay on the day of retirement

Criteria: Entry before September 8, 1980

2) High-36:

Details: Defined Benefit that equals 2.5% times the number of years of service times the average of the member’s highest 36 months of basic pay

Criteria: Entry on or after September 8, 1980, but before August 1, 1986 OR Entered on or after August 1, 1986, and did not choose the Career Status Bonus and REDUX retirement system

3) CSB/REDUX:

Details: Career Status Bonus $30,000 lump sum payment at 15th year of service with obligation to serve through 20 years + defined benefit.
    Defined Benefit is
    (a) Prior to age 62: 2.5% times the number of years of service minus 1.0% for each year of
    service less than 30, times the average of the member’s highest 36 months of basic pay
    (b) At age 62 and after: 2.5% times the number of years of service times the average of the member’s highest     36 months of basic pay

Criteria: Entered on or after August 1, 1986, but before January 1, 2003 AND elected to receive the Career Status Bonus.

4) BRS (Blended Retirement System):

Details: Blended defined benefit and defined contribution plan.
    
    Defined Contribution: All covered members receive a Government contribution that equals 1% of basic or inactive duty pay to a tax-advantaged retirement account (Thrift Savings Plan (TSP)) after 60 days following the entry into Uniformed Service. Additionally, covered members have the ability to receive up to an additional 4% matching contribution from the Government to TSP beginning after 2nd year of service through 26th year of service.
    
    Defined Benefit: Members who otherwise qualify for a retirement based on longevity of service will also receive a defined benefit that is 2.0% times the number of years of service times the member’s highest 36 months of basic pay.

Criteria: Entered the Uniformed Services for the first time on or after January 1, 2018 (automatic enrollment), or entered before December 31, 2017 and elected to opt into BRS during the opt-in period

More details along with pay scales can be found here:
https://militarypay.defense.gov/Pay/Retirement/

*Note - These given details are referenced from given website.
