Why the IRS sends a Proposed Adjustment

The IRS compares information it receives from employers, banks, and other payers against the return you filed. When totals don’t match, the agency issues a Proposed Adjustment to explain the discrepancy and propose corrected tax, penalties, or both. Common examples include unreported 1099 income, overstated deductions, or mismatched filing status (IRS guidance: Understanding Your Tax Return) (IRS, https://www.irs.gov/individuals/understanding-your-tax-return).

How the IRS communicates it and typical names for the notice

Most Proposed Adjustments arrive as a letter or notice (for example, the CP2000 series for unreported income). The notice will: explain the proposed change, show how the IRS calculated it, provide a response deadline, and list next steps if you agree or disagree (see Understanding Your Notice or Letter from the IRS) (IRS, https://www.irs.gov/individuals/understanding-your-notice-or-letter-from-the-irs).

Step‑by‑step response checklist (what to do first)

  1. Read the notice carefully — note the tax year, the line items the IRS questioned, and the deadline.
  2. Don’t ignore the deadline — responding timely preserves appeal rights and can stop automated assessments.
  3. Compare the IRS’s figures with your return and source documents (W‑2s, 1099s, bank statements, receipts).
  4. Gather supporting documents that directly address the IRS’s point (copies of forms, invoices, canceled checks, contemporaneous logs).
  5. Reply using the method and address the notice specifies — include a cover letter that states whether you agree or object and attach clear, labeled evidence.

For a ready template and organization tips, see our guide on Building an Effective Audit Response Packet: Templates and Organization Tips.

Common types of Proposed Adjustments

  • Unreported income (mismatched or missing 1099/W‑2).
  • Disallowed or reduced deductions (business expenses, charitable contributions).
  • Incorrect filing status or dependents.
  • Credits disallowed or recalculated (EITC, education credits).

Documentation that matters most

  • Third‑party forms (W‑2, 1099‑MISC/NEC, 1099‑INT/Div).
  • Receipts, invoices, and bank records linked to amounts claimed.
  • Written agreements, logs (mileage, rental), or contemporaneous notes proving business purpose.
  • A concise cover letter mapping each IRS line item to the documents you provide.

See also our practical checklist for correspondence audits: Preparing for an IRS Correspondence Audit: What to Expect and How to Respond.

If you disagree — appeals and next steps

If you don’t agree with the Proposed Adjustment, you must respond and explain why. Requesting an appeal or conference with the IRS Appeals Office is usually the next step if the IRS stands by its change. Appeals rights and procedures vary by notice and whether an assessment has been made — review the notice carefully and preserve response deadlines (see IRS audits guidance) (IRS, https://www.irs.gov/businesses/small-businesses-self-employed/understanding-irs-audits).

Potential consequences of ignoring the notice

Ignoring a Proposed Adjustment can lead to a formal assessment, added penalties, interest, and enforced collection. Responding can stop or limit those outcomes and preserve procedural protections, including appeal rights.

When to call a tax professional

Engage a CPA, EA, or tax attorney if:

  • The proposed tax or penalties are material;
  • The factual dispute is complex (e.g., allocation of income among years, complex S‑corp/partnership items);
  • You need representation for an in‑person audit or appeals conference.
    A professional can organize documents, draft a strong cover letter, and represent you in negotiations.

Quick timeline example

  • Day 0: Notice mailed (you typically have 30 days to respond; check your notice).
  • Day 7–21: Gather documents and prepare response.
  • Day 30: Submit response; if you’ve requested more time, ask in writing before the original deadline.
  • After submission: IRS reviews and either accepts, modifies, or issues a formal assessment; appeals window opens on the assessment.

Practical tips to reduce future Proposed Adjustments

  • Keep accurate, labeled records and digital backups for at least three years (longer for complex items).
  • Reconcile 1099s/W‑2s and bank records before filing.
  • When in doubt, attach explanatory statements to your return (where permitted) and consider amended returns for known errors.

Sources & further reading

IRS — Understanding Your Tax Return (https://www.irs.gov/individuals/understanding-your-tax-return)
IRS — Understanding Your Notice or Letter from the IRS (https://www.irs.gov/individuals/understanding-your-notice-or-letter-from-the-irs)
IRS — Understanding IRS Audits (https://www.irs.gov/businesses/small-businesses-self-employed/understanding-irs-audits)

Professional disclaimer

This article is educational and does not replace personalized tax advice. For help responding to a specific notice or for representation, consult a qualified tax professional.