Segment Reporting Explained: ASC 280, the CODM Test, and What ASU 2023-07 Changed

A diversified company reports one set of consolidated financial statements, but it is not one business. A coatings division earning a 16% operating margin and a specialty films division earning 22% blend into a single consolidated margin that describes neither. Segment reporting is the disclosure regime that pulls those businesses back apart — and it is the raw material every sum-of-the-parts valuation is built from.

It is also the disclosure most investors read least carefully, because the rules governing it are unusual: segments are not defined by industry logic, or by what would be most useful to an outside analyst. They are defined by how the company's own senior decision-maker happens to look at the business. That single design choice explains most of what is useful about segment data, and all of what is frustrating.

This guide covers how segments are determined under ASC 280, the quantitative tests that decide which ones must be reported, what ASU 2023-07 added in 2023, a worked example applying every test to one set of numbers, and the places where segment data misleads.

The Management Approach

ASC 280 uses what is called the management approach. An operating segment is a component of a company that meets three conditions at once:

1. It engages in business activities from which it may earn revenues and incur expenses.
2. Discrete financial information about it is available.
3. Its operating results are regularly reviewed by the chief operating decision maker to assess performance and decide how to distribute resources.

The third condition is the load-bearing one. The chief operating decision maker — the CODM — is a function rather than a job title. It may be the chief executive, but it may equally be the chief operating officer, an executive committee, or the board. Whoever actually reviews component results and decides where resources go is the CODM, and the components they review are the operating segments.

The consequence is that segments are a description of an internal management structure that has been made public. This cuts both ways.

What it gives you. The segment note reflects how the business is genuinely run, not how a standard-setter imagined it should be organised. When management reorganises, the segments change, and the change itself is information: it tells you the internal reporting line moved.

What it costs you. Segment definitions are not comparable between companies, even direct competitors in the same industry. One firm may report three geographic segments; a near-identical firm may report two product segments. Neither is wrong. Any cross-company comparison of segment data requires establishing first that the segments describe comparable things, and frequently they do not.

Which Segments Must Be Reported

Not every operating segment appears in the note. An operating segment becomes a reportable segment if it clears any one of three quantitative thresholds. Each test uses the combined figures for all operating segments, not consolidated totals.

Any single test passed makes the segment reportable. A segment failing all three may still be reported at management's discretion, and may be aggregated with other similar segments or swept into an "all other" category.

Two further rules sit on top of the thresholds.

The 75% coverage rule. If the total external revenue of the reportable segments is less than 75% of consolidated revenue, additional operating segments must be identified as reportable until the 75% level is reached — even though none of them individually cleared a threshold. This exists to stop a company with many small divisions from disclosing almost nothing.

Aggregation. Two or more operating segments may be combined into one reportable segment only if aggregation is consistent with the objectives of the standard, the segments have similar economic characteristics, and they are similar in all of the following: the nature of the products and services, the nature of the production processes, the type or class of customer, the methods used to distribute products, and, if applicable, the nature of the regulatory environment.

Aggregation is where the most judgement — and the most disclosure loss — happens. The criteria are demanding on paper, and the "similar economic characteristics" test in particular has been a recurring subject of comment letters from regulators. In practice, aggregation is the mechanism by which a company with economically distinct businesses can present a smaller number of broader segments.

The Single-Segment Problem

The sharpest limitation of the regime has historically been the company that reports exactly one segment. If the CODM reviews the business as a single unit, there is one operating segment, and the segment note collapses into a restatement of the income statement.

This is not necessarily an abuse. A genuinely focused company has one segment because it is one business. But it also meant that a company with economically distinct divisions could, by organising its internal reporting a certain way, disclose materially less than a competitor with identical operations. And under the pre-2023 rules, a single-segment entity was exempt from most segment disclosure requirements — so the entities whose internal economics were least visible were also the ones required to say least about them.

Whatever the cause, the effect on an outside analyst is the same: the divisional margin structure is not observable, and any sum-of-the-parts work has to be built on estimates rather than disclosure.

Three partial substitutes exist, all weaker than a real segment note:

• Entity-wide disclosures. Even a single-segment company must disclose revenue by product or service group, revenue and long-lived assets by geography (the country of domicile, and each material individual country), and the existence of any single customer accounting for 10% or more of revenue. These are required of all entities regardless of segment structure.
• Management commentary. Divisional detail often appears in the management discussion, earnings presentations, or investor day materials without appearing in the audited note. It is useful and it is not audited to the same standard.
• Prior-period disclosure. When a company changes its segment structure, it must restate prior periods. A company that once reported more segments leaves a historical record of the split.

What ASU 2023-07 Changed

In November 2023 the FASB issued ASU 2023-07, Improvements to Reportable Segment Disclosures — the first substantial revision to the regime since ASC 280 replaced its predecessor. It did not change how segments are determined. The management approach, the three thresholds, the 75% rule and the aggregation criteria are all unchanged. What changed is how much must be said about each segment once identified.

Significant segment expenses. The central addition. For each reportable segment, a company must now disclose the significant expense categories that are regularly provided to the CODM and included in the reported measure of segment profit or loss. Before this, a typical segment note gave revenue and a profit figure with essentially nothing between them. Now the composition of that profit is partially visible.

Other segment items. Because only significant expenses regularly provided to the CODM are disclosed, the listed items will not reconcile to segment profit. The residual is disclosed as a single "other segment items" amount, accompanied by a qualitative description of what it contains.

CODM identification. The title and position of the CODM must be disclosed, along with an explanation of how the CODM uses the reported segment profit measure to assess performance and decide how to distribute resources. This makes the previously opaque foundation of the whole regime explicit.

Multiple profit measures permitted. A company may report more than one measure of segment profit or loss, provided at least one is the measure most consistent with the amounts in the consolidated statements.

Interim disclosure. Segment disclosures that were previously required only annually must now also be provided in interim periods.

Single-segment entities included. Public entities with a single reportable segment must provide all of the required segment disclosures, closing the exemption described above.

The amendments are effective for annual periods beginning after 15 December 2023, and for interim periods within fiscal years beginning after 15 December 2024, applied retrospectively to all prior periods presented. For an analyst, the retrospective application matters: the comparative history arrives alongside the first disclosure rather than accumulating over several years.

Worked Example: Applying Every Test

Northbridge Materials is an illustrative construction used to demonstrate the arithmetic; it is not a real company and the figures describe no security. It has three operating segments. All amounts are in millions.

Revenue test. Combined segment revenue is 4,000, so the threshold is 400. Industrial Coatings (2,400) and Specialty Films (1,350) clear it. Emerging Adhesives at 250 is 6.3% of the combined figure and fails.

Profit or loss test. The combined profit of the segments not reporting a loss is 384 + 297 = 681. The combined loss of the segments reporting a loss is 40. The greater of the two is 681, so the threshold is 68.1. The absolute loss of Emerging Adhesives is 40, which fails.

Assets test. Combined segment assets are 3,350, so the threshold is 335. Emerging Adhesives holds 300 and fails, narrowly — a point worth noting, because a modest amount of additional capital deployed into that division would make it separately reportable and change what the company must disclose.

75% coverage rule. External revenue of the two reportable segments is 3,750 against consolidated revenue of 4,000 — 93.8%, comfortably above 75%. No additional segment needs to be added.

Emerging Adhesives is therefore not separately reportable and would be presented within an "all other" line. Note what has just happened: the loss-making division, and the one most likely to be either the future of the company or a persistent drain on it, is the one that disappears from view.

Reading the significant expense disclosure

Under ASU 2023-07, the Industrial Coatings segment might now be presented like this:

The three named categories are the significant expenses regularly provided to the CODM. The 276 residual is the "other segment items" figure, which the note must describe qualitatively. Raw materials at 47.9% of segment revenue is the disclosure that did not exist before the amendment, and it is the number that makes input-cost sensitivity for this division estimable rather than guessed.

A sum-of-the-parts built on the note

Applying separate multiples to each division's operating profit, with the loss-making division valued on revenue instead:

Two lines in that table are where the work actually is. Unallocated corporate cost — the head-office expense that belongs to no segment — reduces the gross figure by roughly 10% here, and it is routinely omitted from casual sum-of-the-parts arithmetic. Net debt is a further deduction that has nothing to do with the segment note at all. A "parts" figure quoted without both is not an equity value.

Where Segment Data Misleads

Segment profit is not a GAAP measure. The measure reported is whatever the CODM reviews. It may exclude interest, taxes, amortisation of acquired intangibles, share-based compensation, restructuring, or any combination. ASC 280 requires a reconciliation of the segment total to the consolidated figure, and reading that reconciliation is not optional — two companies reporting "segment operating income" may be reporting different things.

Intersegment revenue inflates the denominator. The revenue test counts intersegment revenue, and segment revenue as presented may include internal transfers eliminated in consolidation. Transfer pricing between segments is a management policy, so a company can shift reported profit between divisions without any change in economics.

Corporate and unallocated costs distort segment margins. Costs held at corporate never touch a segment margin, so summed segment profit typically exceeds consolidated operating profit. Comparing a segment margin against a standalone competitor's consolidated margin compares a figure carrying no head-office burden against one that does.

Redefinitions destroy the time series. When a company reorganises, prior periods are restated — which preserves comparability going backward from the new structure, but means a segment margin series assembled from successive annual reports over several years may be splicing together different definitions. Rebuild the series from the most recent restatement rather than from the original filings.

Aggregation hides dispersion. A reportable segment may be several operating segments combined. A 19% aggregate margin can be a 30% business and a 6% business, and the note will not say so.

Allocated assets are approximate. Segment asset figures depend on allocation conventions for shared facilities, goodwill and working capital. Any return-on-capital measure computed at segment level inherits the imprecision of those conventions — an important caveat when segment return on invested capital is used to rank divisions.

How This Shows Up in Equity Rank

Equity Rank's valuation models operate on consolidated financial data, because consolidated figures are reported on a consistent basis across the full coverage universe while segment structures are company-specific by design. A multiple derived from a segment note would not be comparable between two companies without a manual judgement about whether their segments describe the same thing.

That is a deliberate scope boundary rather than a claim that segment data is unimportant. For a diversified company, the consolidated view is the starting point and the segment note is where the analysis continues by hand. The enterprise value deep dive covers the bridge from a parts-based figure to an equity value, the holding company discount guide covers why a diversified structure may trade below that figure, and the EV/EBITDA calculator accepts divisional inputs of the reader's own construction.

Frequently Asked Questions

Who is the chief operating decision maker? It is a function, not a title. Whoever regularly reviews component operating results and decides how resources are distributed is the CODM — potentially the chief executive, the chief operating officer, an executive committee, or the board. Since ASU 2023-07, the title and position must be disclosed.

Can a company choose its segments to disclose less? Not directly, because segments must follow the internal reporting structure the CODM actually uses. But the internal structure is itself a management choice, and the aggregation criteria involve judgement. The regime constrains the disclosure given a structure; it does not constrain the structure.

Why does a company report a single segment? Either it genuinely operates as one business, or the CODM reviews it as one unit. Since ASU 2023-07, a public entity with one reportable segment must still provide the full segment disclosures, so the disclosure gap that previously accompanied this is substantially narrower.

Do segment profits add up to consolidated operating profit? Usually not. Corporate and unallocated costs, intersegment eliminations, and items excluded from the CODM's measure all sit outside the segment totals. ASC 280 requires a reconciliation, which is where the difference is explained.

Does IFRS work the same way? IFRS 8 was converged with the US standard and uses the same management approach and the same 10% thresholds. The 2023 amendments described here are a US GAAP change and have no direct IFRS equivalent, so the significant-expense disclosure may be absent from an IFRS filer.

How far back does segment history go after a reorganisation? Prior periods presented in the current filing are restated onto the new structure. Older filings retain the previous structure without restatement, so a long series must either be rebuilt from restated comparatives or treated as broken at the reorganisation date.

This content is for educational and informational purposes only and does not constitute investment advice. Equity Rank is not a registered investment adviser. Northbridge Materials is an illustrative construction and does not describe any real company; the figures are arithmetic demonstrations, not estimates about any security. Accounting standards are amended over time and their application differs by filer, industry and reporting period — segment disclosures should be verified against primary filings before use.