The result is your single life benefit. Retire before your unreduced date and an early cut applies; other payment options pay less so a beneficiary gets something. Buying service adds years. Or let the calculator do the arithmetic (a Tier 2 example is filled in).
Final average salary
Tier 1: highest 3 fiscal-year (July 1-June 30) salaries / 36. Tier 2: highest 5 fiscal-year salaries / 60. The years need not be consecutive. Handbook p. 18, Final Average Salary; p. 43, Final Average Salary; NDCC 15-39.1-10(2); Retirement Guide (2023) p. 3
Earnings for teaching, supervisory, administrative and extracurricular duties in a plan year, plus pre-tax salary reductions (125, 132(f), 401(k), 403(b), 414(h), 457). Excludes fringe benefits, insurance, unused leave payouts, retirement or termination payments, non-teaching pay, payments in lieu of benefits, signing and other bonuses. The IRC 401(a)(17) limit applies to members who joined on or after July 1, 1996. Handbook pp. 5-6, Salary, Excluded Salary; p. 42, Bonus; NDCC 15-39.1-04(10)
Service credit
700 or more compensated hours in a fiscal year earn 1 year. Fewer hours earn hours ÷ 700. The handbook's example: 650 hours ÷ 700 = 0.929 years. Handbook p. 13, Earned Service Credit; Benefit presentation PDF p. 12
Bought service (such as air time) counts in the formula. Service in NDPERS or the Highway Patrol plan counts toward vesting and the Rule of 85 or 90, but not in the TFFR formula unless you choose the combined calculation at retirement. Handbook p. 13, Vesting; p. 4, Dual Membership; p. 14, Eligibility item 4; NDCC 15-39.1-11; 15-39.1-10.3(1)(a)
A minimum in the law
Members who retired on or after July 1, 1993 may not receive less than $10 a month per year of teaching up to 25 years plus $15 a month per year over 25. At 25 years that's $250 a month; at 30 years, $325. NDCC 15-39.1-10(3)
NDCC 15-39.1-10(3) sets a floor of $10/month per year up to 25 years and $15 over 25. The handbook does not mention it, and it is unclear whether it applies after the early-retirement reduction.
What we do: the floor is applied to the final single life amount, with a note
What would settle it: RIO confirmation, or a benefit estimate for a low-salary early retiree.From the sources
- Monthly single life benefit = final average monthly salary x years of service credit x 2.0%.Handbook p. 18, Formula; NDCC 15-39.1-10(2)
- Check with TFFRThe law sets a minimum benefit of $10 a month per year of service up to 25 years plus $15 a month per year over 25, for members who retired on or after July 1, 1993.NDCC 15-39.1-10(3)
- Tier 1: the total of your 3 highest fiscal-year (July 1-June 30) salaries divided by 36. Tier 2: the total of your 5 highest divided by 60. The years do not have to be in a row.Handbook p. 18, p. 43; NDCC 15-39.1-10(2); Retirement Guide (2023) p. 3
- Salary counts teaching, supervisory, administrative and extracurricular pay. It does not count fringe benefits, insurance, unused leave payouts, retirement or termination payments, non-teaching pay, payments in lieu of benefits, or bonuses (including signing and retention bonuses).Handbook pp. 5-6, Salary, Excluded Salary; p. 42, Bonus
- You earn 1 year of service credit for 700 or more compensated hours in a fiscal year, at most 1 a year. Fewer hours earn a fraction: 650 hours = 650 / 700 = 0.929 years.Handbook p. 13, Earned Service Credit; NDCC 15-39.1-27
Questions
What is the TFFR formula?
Final average monthly salary × years of service credit × 2% = your monthly single life benefit.
What is final average salary?
The total of your 3 highest fiscal-year salaries ÷ 36 (Tier 1), or your 5 highest ÷ 60 (Tier 2). The years don't have to be in a row.
How is service credit counted?
700 compensated hours in a fiscal year (July 1-June 30) earn 1 year; fewer hours earn a fraction; never more than 1 a year.
Do bonuses count?
No. Signing, retention and other bonuses, unused leave payouts, insurance and termination payments are not TFFR salary.
Source: Teachers' Fund for Retirement Member Handbook, 5/7/2026, pp. 5-6, 13, 18-19, 42, 43. Also: Retirement Guide (2023); Benefit presentation (Fall 2025); NDCC 15-39.1-04, 15-39.1-10, 15-39.1-27. Last reviewed .