Tier One
1.5% a year
Compounded each January 1 once you qualify.
MCA 19-20-719; Montana TRS web page: What is GABA; Actuarial Valuation (July 1, 2025), p. 51, Appendix B (GABA)Tier Two
0.5% now
0.5% while Montana TRS is under 90% funded. At 90% or more, the board may set up to 1.5%, if the raise wouldn't drop funding below 85%.
MCA 19-20-719; Montana TRS web page: What is GABA; Actuarial Valuation (July 1, 2025), p. 51, Appendix B (GABA)Funding
73.44%
Funded ratio on July 1, 2025, from the latest valuation.
Montana TRS FY2025 ACFR, p. 1 (letter of transmittal, Plan Funding Status); Actuarial Valuation summary 2025, p. 15The facts
- Montana TRS benefits get a Guaranteed Annual Benefit Adjustment (GABA) each January once at least 36 monthly payments have been made before that January 1.MCA 19-20-719(3); Montana TRS web page: What is GABA
- Tier One GABA is 1.5% a year. Tier Two GABA is 0.5% while the system is under 90% funded; above that the board may set up to 1.5%. The system was 73.44% funded on July 1, 2025.MCA 19-20-719(1)-(2); Montana TRS web page: What is GABA; Montana TRS FY2025 ACFR, p. 1
- Example: if you retire July 1, 2026, your 36th payment comes at the end of June 2029, so your first GABA is January 1, 2030.MCA 19-20-719(3); Montana TRS web page: What is GABA (our arithmetic)
- The GABA is similar to a Social Security cost-of-living adjustment, but it's set in Montana TRS law and isn't tied to outside economic measures.Montana TRS web page: What is GABA
- If you've had at least 36 monthly payments by December 31, the GABA starts with your next benefit, paid on the last business day of January, and Montana TRS mails a pay stub showing it. Joint annuitants and other benefit recipients get it too.Montana TRS web pages: What is GABA; Glossary of Terms (benefit recipient)
- If Montana TRS reaches a 90% funded ratio, the board may raise the Tier Two GABA in 0.5% steps, up to 1.5%, but not if the latest valuation shows the raise itself would likely push the funded ratio below 85%.Montana TRS web page: What is GABA
When your first GABA comes
You need at least 36 monthly payments before a January 1. Montana TRS pays at the end of each month, starting with your retirement month.
- Retire July 1, 2026: first GABA January 1, 2030.
- Retire January 1, 2026: first GABA January 1, 2029.
Both dates are our arithmetic on the rule, not Montana TRS examples. MCA 19-20-719; Montana TRS web page: What is GABA; Actuarial Valuation (July 1, 2025), p. 51, Appendix B (GABA)
$2,500 a month over eight Januaries
Our engine: a $2,500 benefit starting July 1, 2026, at today's rates (1.5% and 0.5%).
| January 1 | Tier One | Tier Two |
|---|---|---|
| Jan 1, 2027 | $2,500.00 | $2,500.00 |
| Jan 1, 2028 | $2,500.00 | $2,500.00 |
| Jan 1, 2029 | $2,500.00 | $2,500.00 |
| Jan 1, 2030first GABA | $2,537.50 | $2,512.50 |
| Jan 1, 2031 | $2,575.56 | $2,525.06 |
| Jan 1, 2032 | $2,614.19 | $2,537.69 |
| Jan 1, 2033 | $2,653.40 | $2,550.38 |
| Jan 1, 2034 | $2,693.20 | $2,563.13 |
See your own first GABA date in the calculator. Working after you retire? See the earnings limit.
Questions
What is the Montana TRS GABA?
The Guaranteed Annual Benefit Adjustment: a raise each January 1, set in law rather than tied to inflation. 1.5% for Tier One. For Tier Two, 0.5% while the system is under 90% funded.
When does my first GABA come?
On the January 1 after at least 36 monthly payments. Retire July 1, 2026 and it's January 1, 2030; retire January 1, 2026 and it's January 1, 2029.
Can the Tier Two GABA go up?
Only if the system is at least 90% funded and the raise wouldn't drop it below 85%; then the board may set up to 1.5%. It was 73.44% funded on July 1, 2025.
Source: Montana TRS: Understand Your Benefits (web page) and fact sheets, Fetched Nov. 12, 2026; fact sheets revised 2019-2026. Also: Montana TRS web page: What is GABA; Actuarial Valuation (July 1, 2025); FY2025 Annual Comprehensive Financial Report; Actuarial Valuation summary (2025); MCA § 19-20-719. Last reviewed .