Why Was Your Return Selected for an IRS Audit? (and What Happens Next)

If you have just received an IRS audit notice, the first question is almost always the same: why me? Did the IRS catch something specific? Did a software algorithm flag the return? Did someone report you? Was it random?

The honest answer is that IRS audit selection is rarely random, and “why was I selected for an IRS audit” usually has a specific, identifiable answer. The IRS receives more than 150 million individual returns each year and can examine only a small fraction of them.

By the time a return is selected for audit, it has typically survived multiple layers of screening, and the selection signals something specific about the return, the taxpayer, or the context.

This article walks through the main paths returns take to audit, explains what each path signals about the IRS’s interest in the case, and provides a practical overview of what happens after a return is selected.

The perspective is informed by Kugelman Law attorney Otto Bosch, who served as a Revenue Agent in the IRS Global High Wealth Group within the Large Business and International (LB&I) Division before joining the firm in February 2026.

The Basic Reality of IRS Audit Selection

Audit selection is a triage. The IRS uses a combination of statistical models, information matching systems, project initiatives, and human judgment to identify the returns most likely to produce meaningful adjustments. Every return that reaches a Revenue Agent’s desk has passed through that triage, which means by the time the examination opens, the IRS has already decided the return is worth investing real resources in.

The corollary matters. Selection is not random, but it also does not mean the IRS has already concluded that the return is wrong. It means the IRS believes there is enough probability of a meaningful adjustment to justify the cost of the audit. The defense’s job is to test that probability in order to show that the issues the IRS expected to find either do not exist or have a defensible explanation.

The Main Paths Returns Take to Audit

Returns reach audit through several distinct mechanisms. The path tells the defense team something about how the case will likely develop.

DIF Scoring (Discriminant Function System)

The Discriminant Function (DIF) system is the IRS’s statistical model for scoring returns based on the likelihood that an examination would produce an adjustment. Every individual return is assigned a DIF score. High-DIF returns are routed for review and potential selection.

The specific factors the DIF model weights are not public, but the model is built on historical audit results — meaning returns with characteristics similar to returns that have produced adjustments in the past will score higher. Returns with characteristics that historically correlate with clean audits will score lower. Most ordinary individual audits begin as DIF-selected cases.

Information Matching

The IRS receives extensive third-party information returns — W-2s, 1099s, K-1s, broker statements, Forms 5498, foreign account reports under FATCA, cryptocurrency exchange data, mortgage interest statements, and many others. These information returns are matched against the corresponding amounts on filed returns.

Where the data matches, no audit. Where the data does not match — a 1099 the IRS received that is not reported on the return, a K-1 missing from the return entirely, a broker statement showing dispositions not reflected in Schedule D — the mismatch generates a notice. Small mismatches typically produce a CP2000 notice that resolves through correspondence. Material mismatches can escalate into a full examination.

Related-Return Pickups

When the IRS is examining one return and identifies issues that connect to another taxpayer’s return, the related return can be opened for examination as well. A partnership audit triggers examinations of the partners. A corporation audit can trigger shareholder examinations. Family-owned business structures can produce coordinated audits across multiple related taxpayers.

Related-return pickups are one reason a single audit can quickly grow. They are also one reason that examinations involving high-net-worth families, private equity structures, and other multi-entity arrangements tend to expand once the IRS begins looking at one piece of the structure.

Compliance Projects and Initiatives

The IRS regularly announces or quietly runs enforcement initiatives focused on specific issues — syndicated conservation easements, microcaptive insurance arrangements, deferred legal fee structures, cryptocurrency reporting, foreign account compliance, employee retention credit claims, and others. Returns within the scope of an active initiative are far more likely to be selected.

Project-driven examinations look different from DIF-driven examinations. The agent has typically been trained specifically on the project’s target issue, has examined other taxpayers in the same project, and has internal guidance on what positions to develop. Recognizing a project-driven audit early is one of the most valuable defensive insights an examination can produce.

Whistleblower and Informant Referrals

The IRS Whistleblower Program pays awards for actionable information about tax noncompliance, and substantiated referrals can result in examination. Whistleblowers are sometimes disgruntled former employees, sometimes former spouses, sometimes business partners, sometimes professional informants who specialize in identifying patterns of noncompliance.

A whistleblower-initiated audit is structurally different from a DIF-selected audit. The IRS already has specific information about specific issues from someone with inside knowledge. The agent’s working hypothesis is more specific, and the IDR responses will be evaluated against information the IRS already has.

LB&I and Global High Wealth Selection

For the most complex high-net-worth and corporate examinations, returns are selected through specialized risk-based processes within the Large Business and International division. The Global High Wealth Group within LB&I uses an enterprise audit approach that considers the entire web of related entities, trusts, partnerships, and personal returns associated with a wealthy taxpayer as a coordinated whole.

Selection by LB&I or the Global High Wealth Group signals that the IRS has decided the case warrants its most experienced examination resources. These cases tend to involve longer timelines, multiple specialists, integrated analysis across many entities, and significant dollar exposure.

Random Selection (National Research Program)

The IRS periodically conducts the National Research Program (NRP), in which a statistically representative sample of returns is audited regardless of their DIF score. The NRP exists to calibrate the DIF model and to measure the tax gap. NRP audits feel random because, within their sample, they are — but the sample itself is small relative to the overall audit caseload.

How to Read Your Audit Notice for Selection Clues

The audit notice itself contains information that helps identify the selection path:

• The issuing office. Notices from IRS Service Centers usually indicate correspondence-level matters driven by information matching. Notices from field offices generally indicate more substantive examinations.
• The examiner’s title. A Tax Examiner suggests a correspondence audit. A Tax Compliance Officer suggests an office audit. A Revenue Agent suggests a field audit. Identification with LB&I or the Global High Wealth Group suggests a specialized examination.
• The issues identified. Where the notice identifies a specific issue (a missing 1099, an unsubstantiated deduction, a credit eligibility question), the selection was likely driven by that issue. Where the notice references broad areas of the return (Schedule C in its entirety, all foreign account activity, all cryptocurrency transactions), the selection was likely broader.
• The form referenced. CP2000 notices indicate information matching mismatches. Letter 566 typically initiates correspondence audits. Letter 2205 typically initiates field examinations.

For more on how the type of audit identified in your notice affects defense strategy, see our article on field audit vs. office audit vs. correspondence audit.

What the Selection Path Tells You About Your Audit

Reading the selection path is one of the first defensive moves in any audit. Different paths suggest different scope, different agent posture, and different defense priorities:

• DIF-selected audits tend to be focused on the specific issues that drove the score. Strong substantiation on those issues often produces a clean closing.
• Information-matching audits are data-driven and narrow. The defense’s job is typically to substantiate the reported position or to demonstrate why the third-party data is inaccurate.
• Related-return audits follow specific connecting issues. The defense should anticipate that the agent already has information from the related taxpayer’s return.
• Project-driven audits concentrate on the project’s target issue. The agent’s positions are likely well-developed; the defense’s job is to engage them on the specific facts of the case.
• Whistleblower audits assume the IRS has specific information from an insider. The defense should expect targeted questions and should not assume the agent is starting from neutral.
• LB&I and Global High Wealth audits are the most resource-intensive examinations the IRS conducts. The defense methodology needs to match the agency’s commitment to the case.

What Happens After Selection — The Audit Lifecycle

Once a return is selected and an examination opened, the audit unfolds along a fairly predictable arc:

Pre-contact analysis. Before any notice goes out, the agent reviews the return, prior-year filings, selection notes, and third-party data. A working hypothesis about the case is formed before the taxpayer hears anything.

Initial notice and opening conference. The taxpayer receives the audit notice. Depending on the audit type, an opening conference may be scheduled.

Information Document Requests (IDRs). The agent issues IDRs requesting documents and information. The first IDR is one of the most important documents in the entire audit — we discuss this in detail in our article on how to respond to an IRS IDR.

Issue development and fieldwork. The agent reviews documents, conducts interviews where appropriate, develops issues, and builds workpapers. This phase can last months — sometimes years — for complex examinations.

Closing. The audit closes in one of three ways: no change (the return is accepted as filed), agreed (the taxpayer accepts the proposed adjustments), or unagreed (the case proceeds to Appeals and potentially to U.S. Tax Court).

For a deeper walk-through of how the audit unfolds inside the IRS, see our pillar articles on what an IRS Revenue Agent does and inside the IRS audit playbook.

How Long Will Your Audit Take?

Audit duration varies dramatically by type and complexity:

• Correspondence audits typically resolve in a few months from the initial notice through final closing.
• Office audits typically resolve in three to six months, with the single in-person appointment as the central event.
• Field audits commonly take a year or more for substantive cases, and complex multi-year LB&I or Global High Wealth examinations can run two years or longer.

Several factors affect timing: the complexity of the issues, the responsiveness of the taxpayer and representative, whether specialists are brought in, whether the case proceeds to Appeals, and whether litigation ultimately follows. Faster is generally better for the taxpayer, but rushed responses produce worse outcomes than measured ones.

Common Misconceptions About IRS Audit Selection

Several beliefs about audit selection are common but inaccurate:

“It was random.” Almost never. With limited exceptions like the National Research Program, audit selection is driven by specific factors that flagged the return.

“I was unlucky.” Selection is not luck. It is the output of statistical models, data matching, project initiatives, and human judgment — each of which is calibrated to identify returns that warrant examination.

“The IRS is targeting me.” Very rarely. Targeting in the sense of personal animus is extremely uncommon in modern IRS practice. The selection systems are largely impersonal. What feels like targeting is almost always the output of a model or a project the taxpayer happens to fit.

“If I just amend my return, I can avoid the audit.” Sometimes — but the answer is fact-specific. Amending a return after an audit has been opened typically does not stop the audit, and amending in some scenarios (particularly where criminal exposure is possible) can create more problems than it solves. The decision should be made with counsel.

“Audits are inevitable once you reach a certain income.” High income increases audit probability, particularly for taxpayers reaching Global High Wealth thresholds. But the relationship is probabilistic, not deterministic, and many high-income taxpayers never face audits while many middle-income taxpayers do.

What You Should Do Right Now

If you have just received an audit notice, the right immediate steps are practical and measured:

1. Read the notice carefully. Identify the audit type, the issuing office, the named examiner, the issues raised, and the deadline.
2. Preserve relevant records. Do not destroy or alter any document referenced in the notice or potentially related to the issues raised. Document preservation obligations are serious.
3. Do not respond reflexively. The instinct to “explain things” quickly and put the matter behind you is almost always counterproductive. Unprepared communication with the IRS is one of the most common ways audits go badly.
4. Do not call the agent without preparation. Statements made during informal calls become part of the audit record.
5. Identify what kind of representation you need. For straightforward correspondence audits, your preparer may be sufficient. For substantive examinations, experienced controversy counsel is generally appropriate. We discuss the choice in our article on tax attorney vs CPA for IRS audit defense.
6. If any aspect of the case involves potential criminal exposure — significant unreported income, undisclosed foreign accounts, false statements to the IRS, or fabricated records — retain an attorney before any further communication with the IRS. See our article on eggshell audits explained for the underlying framework.

How Kugelman Law Approaches Selection Analysis

The first thing Kugelman Law does on a new audit matter is read the case before doing anything else. That means analyzing the selection path, identifying the likely scope of the examination, modeling the taxpayer’s exposure across the universe of issues the IRS may develop, and assessing whether any aspect of the case carries elevated risk.

Founder Alex Kugelman brings nearly two decades of federal tax controversy experience, including litigation in U.S. Tax Court and U.S. District Court. Otto Bosch brings the inside-the-IRS perspective from his time as a Revenue Agent in the LB&I Global High Wealth Group — including direct experience with the selection systems and divisional procedures that govern most substantive audits. We covered the strategic value of this combination in detail in our article on why a former IRS revenue agent attorney changes audit defense.

Representative outcomes from the firm’s audit defense practice include a $365,000 tax debt reduced to a zero-dollar liability, a multi-year audit and non-filing matter resolved with minimal payment, and ten years of unfiled returns brought into compliance with a successful outcome. Results depend on specific facts. Past results do not guarantee future outcomes.

Frequently Asked Questions

Does the IRS audit randomly?

Almost never. With limited exceptions like the National Research Program (which audits a small statistically representative sample to calibrate the DIF model), IRS audit selection is driven by specific factors — DIF scoring, information matching, related-return pickups, compliance projects, whistleblower referrals, and specialized division processes. Most audits are the output of identifiable selection paths.

What is a DIF score?

The Discriminant Function (DIF) score is a numerical rating the IRS assigns to each return based on the likelihood that an examination would produce a meaningful adjustment. High-DIF returns are routed for review and potential selection. The specific factors the model weights are not public, but the model is built on historical audit results — meaning returns with characteristics similar to returns that have produced adjustments in the past will score higher.

Can someone report me to the IRS for tax evasion?

Yes. The IRS Whistleblower Program accepts and acts on referrals about tax noncompliance, and the program pays awards in qualifying cases. Common whistleblowers include former employees, former spouses, business partners, and professional informants. Substantiated referrals can result in examinations that look different from DIF-selected audits because the agent has specific inside information from the outset.

Can I prevent future IRS audits?

No taxpayer can guarantee future audit-free status, but several factors reduce audit probability: complete and accurate reporting, clean substantiation, consistency across years, prompt compliance with information reporting obligations, and avoidance of audit-flag positions where alternatives exist. For taxpayers with prior compliance issues, a clean voluntary disclosure or corrected return — handled with experienced counsel — can sometimes resolve historical exposure and lower future audit risk.

How long does the IRS have to audit my return?

The standard statute of limitations on assessment is three years from the date the return was filed (or its due date, if later). It extends to six years for substantial omissions of gross income exceeding 25 percent. There is no statute of limitations for fraudulent returns or non-filed returns. For FBAR and other information return failures, separate limitations periods apply.

Speak With Kugelman Law

If you have received an IRS audit notice — or have reason to believe one is coming — schedule a paid privileged consultation with Kugelman Law. Call (415) 968-1780 or visit our contact page. All consultations are fully protected by attorney-client privilege.

About the Author

Alex Kugelman is the founder and managing attorney of Kugelman Law, a boutique tax controversy and cryptocurrency tax firm serving California and clients nationwide. With nearly two decades of federal tax controversy experience — including litigation in the U.S. Tax Court and U.S. District Court — Alex represents individuals and businesses in their most consequential disputes with the IRS and the California Franchise Tax Board. He is a member of the State Bar of California (No. 255463), admitted to the Bar of the U.S. Supreme Court, and served as San Francisco Chair of the Federal Bar Association’s Tax Division in 2018. He is also a member of the Marin County Assessment Appeals Board and a nationally recognized cryptocurrency tax attorney featured on the Bitcoin.tax podcast and The Mark Milton Show. Read Alex’s full bio.