| Schedule of components of net periodic benefit cost (income) |
The following tables detail the components of net periodic benefit (income) cost for Barnwell’s retirement plans: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pension Plan | | SERP | | Post-retirement Medical | | | Three months ended June 30, | | | 2021 | | 2020 | | 2021 | | 2020 | | 2021 | | 2020 | | | | | | | | | | | | | | Interest cost | $ | 64,000 | | | $ | 73,000 | | | $ | 13,000 | | | $ | 16,000 | | | $ | 12,000 | | | $ | 20,000 | | | Expected return on plan assets | (136,000) | | | (173,000) | | | — | | | — | | | — | | | — | | | | | | | | | | | | | | | Amortization of net actuarial loss | 10,000 | | | — | | | — | | | — | | | 16,000 | | | 20,000 | | | | | | | | | | | | | | | Net periodic benefit (income) cost | $ | (62,000) | | | $ | (100,000) | | | $ | 13,000 | | | $ | 16,000 | | | $ | 28,000 | | | $ | 40,000 | |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pension Plan | | SERP | | Post-retirement Medical | | | Nine months ended June 30, | | | 2021 | | 2020 | | 2021 | | 2020 | | 2021 | | 2020 | | Service cost | $ | — | | | $ | 50,000 | | | $ | — | | | $ | 3,000 | | | $ | — | | | $ | — | | | Interest cost | 193,000 | | | 228,000 | | | 39,000 | | | 49,000 | | | 48,000 | | | 60,000 | | | Expected return on plan assets | (410,000) | | | (508,000) | | | — | | | — | | | — | | | — | | | Amortization of prior service cost (credit) | — | | | 1,000 | | | — | | | (1,000) | | | — | | | — | | | Amortization of net actuarial loss | 30,000 | | | 35,000 | | | — | | | 5,000 | | | 62,000 | | | 60,000 | | | | | | | | | | | | | | | Curtailment cost (income) | — | | | 53,000 | | | — | | | (53,000) | | | — | | | — | | | Net periodic benefit (income) cost | $ | (187,000) | | | $ | (141,000) | | | $ | 39,000 | | | $ | 3,000 | | | $ | 110,000 | | | $ | 120,000 | |
|