FAS 87 pension accounting is the U.S. GAAP framework that tells employers how to measure, recognize, and disclose the cost of defined benefit pension plans. The original Statement of Financial Accounting Standards No. 87 was folded into ASC Topic 715 during the FASB codification, and the core framework carried over intact. It requires employers to put the full economic weight of pension promises on the balance sheet, run a smoothed annual expense through the income statement, and park the volatility in between inside other comprehensive income.
The accounting is layered because the underlying promise is layered. Benefits are paid decades after they are earned, calculated from formulas tied to service and compensation, and funded through a trust whose assets fluctuate daily. The standard builds a measurement system around all of that.
The Obligation Being Measured
The central liability under ASC 715 is the Projected Benefit Obligation (PBO). The PBO is the present value of benefits employees have already earned, but it uses expected future salary levels rather than today’s pay. Most pension formulas base final payouts on compensation near retirement, so using current salary would understate what the plan actually owes. The projection factors in inflation, productivity gains, seniority, and promotions.
A narrower measure, the Accumulated Benefit Obligation (ABO), runs the same present value calculation using only current salary. The ABO shows what the plan would owe if accruals froze today and is used in certain disclosures, but the PBO drives the balance sheet liability and the annual expense.
Plan assets sit on the other side. They are held in a legally separate trust and reported at fair value on the balance sheet date. PBO minus fair value of plan assets equals the plan’s funded status, and that number is what appears on the balance sheet as either a net pension liability or a net pension asset.
The Assumptions That Drive the Numbers
Three assumptions move the reported liability and expense more than anything else. Small changes in any of them produce large changes in the financial statements.
Discount Rate
The discount rate translates future benefit payments into present-value dollars. ASC 715 requires the rate to reference yields on high-quality fixed-income securities, and SEC staff guidance interprets “high quality” as AA or better from a major ratings agency. The maturity of the reference bonds should line up with the timing of the plan’s expected payments. A 50-basis-point move in the discount rate on a large plan can shift the PBO by hundreds of millions of dollars, which makes this the single most consequential input.
Expected Long-Term Return on Plan Assets
The expected return is the long-run rate the plan’s portfolio is anticipated to earn. It is not applied to the fair value of plan assets directly. ASC 715 permits a “market-related value” of plan assets, which may smooth fair value changes over up to five years. The resulting expected return offsets annual pension expense, so a higher assumption lowers reported cost. The incentive to be optimistic is obvious, and that is why analysts scrutinize this number against peer groups. Different smoothing methods are allowed for different asset classes, but no method can stretch recognition beyond five years.
Mortality
How long retirees are expected to live determines how long the plan pays. The IRS publishes updated static mortality tables each year for pension liability calculations, developed from base mortality rates and improvement projections under Treasury regulations.1Internal Revenue Service. Updated Static Mortality Tables for Defined Benefit Pension Plans for 2026 (Notice 2025-40) Plans can choose generational tables, which project ongoing improvements in life expectancy year by year, or static tables that use a single snapshot. Small plans can use the simpler static approach for funding calculations.
The Five Components of Net Periodic Pension Expense
The annual charge that flows through the income statement is Net Periodic Pension Expense (NPPE). It is built from five pieces, and they do not all move in the same direction.
- Service cost is the increase in the PBO from employees earning one more year of benefits. This is the only piece that represents the current-period price of employee labor.
- Interest cost is the growth in the PBO from the passage of time. Because the obligation is measured at present value, it accretes interest each period at the discount rate, much like interest on a debt balance.
- Expected return on plan assets reduces NPPE. It equals the long-term expected return rate applied to the market-related value of plan assets at the start of the period. Using expected rather than actual returns is deliberate; it keeps quarter-to-quarter market swings out of the income statement.
- Amortization of prior service cost spreads the effect of retroactive benefit changes. When an employer increases the formula for years already worked, the resulting jump in the PBO is not expensed immediately. It is amortized over the remaining service years of the employees who benefit from the change, or over remaining life expectancy if most participants are already retired.
- Amortization of net actuarial gains or losses handles the gap between assumption and reality. A discount rate that moved, mortality that diverged from tables, or asset returns that missed expectations all generate actuarial gains and losses. These are initially recorded in other comprehensive income and only flow into NPPE through the corridor approach.
The Corridor That Keeps Expense Smooth
The corridor is the mechanism that keeps actuarial volatility from slamming the income statement every year. At the start of each year, the accumulated unrecognized net gain or loss sitting in OCI is compared against a threshold equal to 10% of the greater of the PBO or the market-related value of plan assets. Anything inside the corridor requires no amortization. Only the excess gets amortized, and even then it is spread over the average remaining service period of active employees.
The result is a long lag between when economic gains and losses occur and when they hit reported earnings. A sharp market downturn can generate a large actuarial loss in year one that does not begin to affect pension expense until year two or three, and then only in slices. Employers can elect faster amortization, and some recognize all gains and losses immediately, but the corridor represents the minimum required.
Income Statement Presentation After ASU 2017-07
Before 2018, all five NPPE components could be lumped into operating expenses. ASU 2017-07 split them up. Service cost must now be presented with other employee compensation inside operating income. Interest cost, expected return on assets, amortization of prior service cost, amortization of gains and losses, and any settlement or curtailment charges all have to appear outside the operating income subtotal.2Financial Accounting Standards Board. Compensation – Retirement Benefits (Topic 715)
This distinction matters because operating income is the metric most analysts use to judge the underlying business. Pulling the financing and smoothing components below the operating line gives a cleaner read. It also narrows what can be capitalized into inventory or property to service cost alone; the other components cannot be capitalized.
Funded Status on the Balance Sheet
ASC 715 requires the balance sheet to show the plan’s funded status as either a net liability or a net asset. When the PBO exceeds plan assets, the employer reports a pension liability. When plan assets exceed the PBO, it reports a pension asset. Companies with multiple plans must aggregate all overfunded plans into a single asset and all underfunded plans into a single liability. Netting an overfunded plan against an underfunded one is not permitted unless the employer has a clear right to shift assets between them.3Financial Accounting Standards Board. FASB EITF Issue Summary – Application of Topic 715 to Market-Return Cash Balance Plans
On a classified balance sheet, the pension liability splits into current and noncurrent portions. The current piece is the amount by which the present value of benefits payable in the next 12 months exceeds plan assets. Pension assets from overfunded plans are always classified as noncurrent.
This full-recognition approach produces real balance sheet volatility. A drop in the discount rate inflates the PBO. A bad year in equities shrinks plan assets. Both hit the balance sheet immediately, even while the income statement expense stays smoothed by the corridor and the expected-return mechanism.
How OCI Bridges the Two Statements
The gap between immediate balance sheet recognition and delayed income statement expense is reconciled through Other Comprehensive Income. When an actuarial loss pushes the PBO beyond what the smoothed expense has absorbed, the difference is recorded in OCI. When a plan amendment raises benefits retroactively, the prior service cost hits OCI immediately. These entries adjust equity through Accumulated Other Comprehensive Income (AOCI) without touching net income.
Over time, AOCI amounts migrate to the income statement through the amortization mechanisms already described. AOCI related to pensions therefore holds three categories: unamortized actuarial gains and losses, unamortized prior service costs or credits, and any remaining transition amounts from initial adoption of the standard. For employers with large, mature plans, the AOCI balance can exceed the pension liability itself.
Settlements and Curtailments
Normal pension accounting assumes the plan continues indefinitely. When that assumption breaks, ASC 715 requires special treatment.
A settlement occurs when the employer eliminates part or all of the pension obligation by transferring assets, typically through annuity purchases from an insurer or lump-sum payments to participants. Settlement accounting accelerates recognition of gains and losses previously deferred in AOCI. The proportion recognized equals the proportion of the PBO that was settled. Settling 30% of the PBO triggers recognition of 30% of the accumulated unrecognized gain or loss in the current period. There is a practical exception: settlement accounting is not required if total settlement cost for the year stays at or below the sum of service cost and interest cost for that year. Employers can set a lower threshold, but whatever policy they adopt must be applied consistently.
A curtailment happens when a significant portion of future benefit accruals is eliminated through a plant closing, a workforce reduction, or a plan freeze. Curtailment accounting accelerates recognition of prior service costs tied to the years of service that will no longer be rendered. If the curtailment also reduces the PBO, the reduction is recognized as a gain and offset against any accelerated prior service cost. When a settlement and curtailment occur together, as often happens in a divestiture, the gains and losses from each are calculated separately and cannot be netted.
Footnote Disclosures
The disclosure framework is designed to let investors assess pension risk independently rather than relying on the summary numbers alone.
Employers must reconcile the beginning and ending balances of both the PBO and the fair value of plan assets. The PBO reconciliation breaks out service cost, interest cost, actuarial gains and losses, plan amendments, and benefits paid. The asset reconciliation shows actual return on assets, employer contributions, participant contributions, benefits paid, and effects of business combinations or divestitures. Together they let an analyst reconstruct exactly how funded status changed during the year.
A separate reconciliation ties funded status to the amounts recognized on the balance sheet and shows how deferred items in AOCI bridge the gap. The components of NPPE must be disclosed individually, which lets analysts separate service cost from the financing and smoothing pieces now sitting below the operating line.
The key actuarial assumptions used to determine both the PBO and the pension expense must also be disclosed: the discount rate, the expected long-term return on plan assets, and the expected rate of compensation increases. This is where real analytical value lives. An employer using an expected return two percentage points above its peers is flattering its earnings, and the disclosure makes that visible. A discount rate above current market yields may be understating the PBO, and disclosure lets analysts recalculate. Companies with material pension obligations typically devote several pages of footnotes to these disclosures, often including sensitivity analyses showing how changes in the discount rate or expected return would affect the liability and expense.
A Boundary Worth Naming
ASC 715 is accounting. It does not set how much cash the employer must contribute, nor does it govern PBGC insurance premiums or the benefit restrictions that apply to underfunded plans. Minimum contributions run on a separate track under IRC Section 430 and ERISA, with their own actuarial calculations, quarterly installment schedule, and 80% and 60% funded-percentage thresholds that trigger restrictions on benefit accruals and lump-sum distributions. PBGC flat-rate and variable-rate premiums are a separate annual cash outflow. Those requirements affect plan economics and belong in any complete analysis, but they do not determine the PBO, the NPPE, or the funded status reported under ASC 715.