Difficulty: Advanced | Prerequisites: Parts 1 and 2 of these notes, understanding of OCI and AOCI from earlier chapters.
This section covers the most technically demanding part of pension accounting: how pension expense is calculated, how gains and losses flow through other comprehensive income (OCI), and where everything lands on the financial statements. It also introduces postretirement health benefits, which follow a similar framework but with important differences. You need a solid grasp of the PBO and plan assets from Part 2 before tackling this material.
Pension expense has five components: service cost, interest cost, expected return on plan assets (reduces expense), amortisation of prior service cost, and amortisation of net gain or loss. Expected return (not actual return) is used for pension expense; the difference between actual and expected goes to OCI. Prior service cost and net gains/losses are initially recorded in OCI and amortised into pension expense over time. The corridor approach governs when net gains/losses in AOCI are large enough to require amortisation. Postretirement health benefits follow a parallel structure but differ in how the obligation is calculated.
Pension expense
The cost recognised in the income statement for providing future pension benefits to employees. It is part of employee compensation and is matched to the period in which employees provide their services.
Expected return on plan assets
The return used in the pension expense calculation. It is the expected rate of return multiplied by the beginning-of-year plan assets. This is not necessarily the same rate as the actuary's discount rate used for interest cost.
Actual return on plan assets
The return the plan assets actually earn during the year. This is used to determine changes in the value of plan assets, not pension expense directly.
Gain or loss on plan assets
The difference between actual return and expected return. If actual return exceeds expected, it is a gain; if it falls short, it is a loss. This difference is recognised in OCI.
Other comprehensive income (OCI)
A section of the financial statements where certain gains and losses are reported that bypass net income. Pension-related items reported in OCI include gains/losses on the PBO, gains/losses on plan assets, prior service cost, and their amortisations.
Accumulated other comprehensive income (AOCI)
The cumulative balance of OCI items, reported in shareholders' equity on the balance sheet.
Corridor
The threshold used to determine whether accumulated net gains or losses in AOCI are large enough to require amortisation into pension expense. The corridor equals the larger of 10% of PBO or 10% of plan assets, both measured at the beginning of the year.
Expected postretirement benefit obligation (EPBO)
The present value of the total health care benefits expected to be received by retirees. It increases each year due to interest cost but is not affected by service cost.
Accumulated postretirement benefit obligation (APBO)
The portion of the EPBO attributed to employee service to date. Analogous to the PBO for pension plans. It is netted with plan assets to report funded or unfunded status on the balance sheet.
Pension expense reflects the cost of providing future retirement benefits during the period employees provide their services. Because the actual cash outflows occur years or decades later, several elements feed into the expense calculation.
The five components are:
1. Service cost (increases expense)
The increase in PBO due to employees earning one more year of service. Actuaries calculate this for the entire employee pool. This is the most straightforward component: employees worked this year, so the company's future obligation grew.
2. Interest cost (increases expense)
The PBO is a present value figure that grows each year as the payment date gets closer. Interest cost = discount rate x beginning-of-year PBO. This is conceptually the same as interest accruing on any long-term liability.
3. Expected return on plan assets (reduces expense)
The plan assets earn income (dividends, interest, capital gains). Higher returns mean the company needs to contribute less to meet its obligations, so returns reduce pension expense.
Critical distinction: pension expense uses the expected return, not the actual return. Expected return = expected rate of return x beginning-of-year plan assets. The expected rate of return may differ from the actuary's discount rate used for interest cost.
The actual return is used to determine changes in the value of plan assets. The difference between actual and expected return is the gain or loss on plan assets, which goes to OCI rather than the income statement.
4. Amortisation of prior service cost (increases expense)
When a plan amendment retroactively increases benefits, the prior service cost initially goes to OCI (with a corresponding increase in the PBO). It is then amortised to pension expense over the average remaining service years of the employee pool.
Amount amortised each year = total prior service cost / average remaining service years.
This gradual transfer from AOCI to pension expense reflects the rationale that the company benefits from the plan amendment over the employees' remaining working years.
5. Amortisation of net gain or loss (increases or decreases expense)
This component uses the corridor approach (see next section).
Important distinctions:
Payments to retirees affect plan assets and PBO but do not affect pension expense
Cash contributions affect plan assets but do not affect pension expense
Net gains and losses arise from two sources: changes in the PBO due to revised actuarial estimates, and differences between actual and expected returns on plan assets. All of these are reported in OCI each year, and the net amount accumulates in AOCI.
Net income is not affected by these gains and losses unless the accumulated net gain or loss in AOCI becomes "large." The corridor approach determines when amortisation is required.
Steps to calculate amortisation of net gain or loss:
Calculate the corridor: the larger of 10% of the beginning-of-year PBO or 10% of beginning-of-year plan assets
Compare the accumulated net gain or loss in AOCI to the corridor
If the accumulated amount exceeds the corridor, the excess is amortised to pension expense over the average remaining service years of active employees
If the accumulated amount is within the corridor, no amortisation is required
Worked example:
Accumulated loss in AOCI at beginning of 2016: $55 million
Beginning PBO: $400 million
Beginning plan assets: $300 million
Average remaining service years: 15 years
Step 1: Corridor = larger of (10% x $400M = $40M) or (10% x $300M = $30M) = $40 million
Step 2: Excess = $55M - $40M = $15 million
Step 3: Amortisation = $15M / 15 years = $1 million added to pension expense for 2016
If this had been a net gain rather than a net loss, the $1 million would have reduced pension expense instead.
Income statement:
Pension expense is reported as a single line item. The five components (service cost, interest cost, expected return on plan assets, amortisation of prior service cost, amortisation of net gain/loss) are disclosed in the notes to the financial statements.
Other comprehensive income (OCI):
Several pension-related items are reported in OCI each year:
Loss (or gain) from revising a PBO estimate
Gain (or loss) when return on plan assets exceeds (or falls below) the expected return
Amortisation of net loss or gain (reclassified from AOCI to pension expense, so it moves out of OCI)
Amortisation of prior service cost (same reclassification)
These amounts are reported net of tax in practice, though the source material's examples are pre-tax.
Balance sheet:
The funded status of the pension plan appears as either a net pension liability or a net pension asset under long-term items.
In AOCI (within shareholders' equity), two pension-related balances are reported:
Net loss (or gain) in AOCI: the cumulative unrecognised gains and losses. A net loss is a debit balance (reduces equity).
Prior service cost in AOCI: the unamortised portion of prior service cost. Also a debit balance.
Example from Global Communication ($ in millions, 2016): net pension liability of $110, net loss in AOCI of ($74), prior service cost in AOCI of ($52).
Health care benefits are the most common postretirement benefit besides pensions. Employers who offer them provide health insurance coverage during retirement for eligible employees (and sometimes spouses and dependents). Eligibility is typically based on reaching a specified length of service and age.
GAAP requires companies to recognise both the obligation and the expense over the years employees work toward eligibility.
Key differences from pension plans:
The amount of health benefits is unrelated to years of service (there is no formula like 1.5% x years x salary)
The benefit amount differs from employee to employee
Retirees may pay part of the cost through premiums
Medicare may offset some of the employer's cost
Medical costs are difficult to predict and tend to increase over time
Two measures of the obligation:
Expected postretirement benefit obligation (EPBO) is the present value of all health benefits expected to be received by retirees. The EPBO increases each year due to interest cost (discount rate x EPBO) but is not affected by service cost, because an additional year of service does not increase the total benefits that will eventually be paid.
Accumulated postretirement benefit obligation (APBO) is the portion of the EPBO attributed to employee service to date. It is analogous to the PBO for pensions and is netted with plan assets on the balance sheet.
Example: If the EPBO is $10,842 and an employee becomes eligible after 35 years and has worked 10 years, the APBO is (10/35) x $10,842 = $3,098.
Attribution: The EPBO is spread over the service period from the date of hire to the date of full eligibility. If eligibility is reached after 35 years, 1/35th of the EPBO becomes the service cost component of postretirement benefit expense each year.
The APBO is increased by both interest cost and service cost. The journal entries for postretirement benefit expense follow the same structure as pension expense entries: debit the expense, credit the obligation, and handle gains, losses, and amortisations through OCI.
The distinction between expected and actual returns on plan assets matters because it determines how much volatility flows into the income statement versus OCI. By using expected returns for pension expense, GAAP smooths the impact of year-to-year market swings on reported earnings. The corridor approach further dampens volatility by keeping accumulated gains and losses out of pension expense until they become large. Analysts evaluating a company's pension risk often look past the income statement to the OCI and AOCI disclosures to understand the full picture.
Students often use the actual return on plan assets in the pension expense calculation. Pension expense uses the expected return. The actual return determines changes in plan asset value; the difference between actual and expected goes to OCI.
A frequent error is thinking that cash contributions to the plan affect pension expense. They do not. Cash contributions increase plan assets but have no effect on pension expense.
Students sometimes confuse the corridor calculation. The corridor is the larger of 10% of PBO or 10% of plan assets (both at beginning of year). Only the excess of the accumulated net gain/loss over the corridor is amortised, and it is divided by the average remaining service years.
With postretirement benefits, students often assume service cost increases the EPBO. It does not. Service cost increases only the APBO (the portion attributed to service to date). The total expected benefit (EPBO) is unaffected by an additional year of service.
⚠️ Be able to calculate pension expense from its five components. Know which ones increase expense (service cost, interest cost, amortisation of prior service cost, amortisation of net loss) and which decrease it (expected return on plan assets, amortisation of net gain).
⚠️ Know the corridor calculation cold. Expect a problem that gives you beginning PBO, beginning plan assets, accumulated net gain/loss in AOCI, and average remaining service years, and asks you to compute the amortisation amount.
⚠️ Understand the difference between expected return (used for pension expense) and actual return (used for plan asset changes). The gap between them is a gain or loss on plan assets, reported in OCI.
⚠️ Be prepared to identify where pension items appear on each financial statement: pension expense on the income statement, pension gains/losses in OCI, net pension liability/asset and AOCI balances on the balance sheet.
⚠️ For postretirement benefits, know the difference between EPBO and APBO, and understand that the EPBO is not affected by service cost.
True or false: Pension expense uses the actual return on plan assets. (False: it uses the expected return.)
Fill in the blank: The corridor is the larger of 10% of ______ or 10% of ______. (Beginning PBO, beginning plan assets.)
True or false: Cash contributions to the pension plan increase pension expense. (False: they increase plan assets but do not affect pension expense.)
True or false: The EPBO increases each year due to service cost. (False: the EPBO increases due to interest cost only. Service cost affects the APBO.)
Fill in the blank: Prior service cost is amortised to pension expense over the average remaining ______ of the employee pool. (Service years.)
Q: A company has a beginning-of-year PBO of $400 million, beginning plan assets of $300 million, accumulated net loss in AOCI of $55 million, and average remaining service years of 15 years. What amount of net loss is amortised to pension expense?
A: Corridor = larger of 10% x $400M ($40M) or 10% x $300M ($30M) = $40 million. Excess = $55M - $40M = $15 million. Amortisation = $15M / 15 years = $1 million added to pension expense.
Q: A company's pension plan has an expected return of 8% on beginning plan assets of $300 million, and the actual return was $30 million. What is the expected return used in pension expense, and what is the gain or loss on plan assets?
A: Expected return = 8% x $300M = $24 million (reduces pension expense). Actual return = $30 million. Since actual ($30M) exceeds expected ($24M), there is a $6 million gain on plan assets, reported in OCI.
Q: How does prior service cost initially affect the financial statements, and how does it eventually reach pension expense?
A: When a plan amendment creates prior service cost, the PBO increases (credit) and OCI is debited. The amount accumulates in AOCI. Each year, a portion is amortised from AOCI to pension expense using the straight-line method over the average remaining service years of the employee pool.
Q: What is the difference between the EPBO and the APBO for postretirement health benefits?
A: The EPBO is the present value of all expected postretirement health benefits. The APBO is the portion of the EPBO attributed to employee service to date. If an employee becomes eligible after 35 years and has worked 10 years, the APBO is 10/35 of the EPBO.
The OCI and AOCI treatment of pension gains, losses, and prior service cost connects to the broader OCI framework covered in earlier chapters (unrealised gains on investments, foreign currency adjustments). The corridor approach is unique to pension accounting but reflects the same smoothing philosophy used elsewhere in GAAP. The postretirement benefits section parallels the pension framework closely, so understanding one makes the other far more accessible.
Pension expense, service cost, interest cost, expected return on plan assets, actual return, gain or loss on plan assets, prior service cost, amortisation, corridor approach, OCI, AOCI, other comprehensive income, accumulated other comprehensive income, net pension liability, net pension asset, funded status, postretirement benefits, EPBO, APBO, retiree health benefits, pension financial statements, pension journal entries, ACCTG 472, Chapter 17