CPA Professional Liability Insurance: Cost, Claims & Coverage Checklist

Quick answer: CPA professional liability insurance is errors and omissions coverage designed for claims arising from a CPA firm’s professional services. Depending on the policy, those services may include tax, audit, attest, compilation, review, bookkeeping and advisory work. The policy language—not the job title “CPA”—determines which services, people and claims are covered.

This 2026 guide focuses on the issues licensed CPA practices should examine: professional-services definitions, audit and advisory exposure, claims-made dates, defense costs, consent to settle, regulatory proceedings, cyber gaps and the information needed for a useful quote.

Who this guide is for: U.S. practices where at least one owner or employee is a licensed CPA, especially firms performing attest, compilation, review, tax or advisory work. If your practice provides accounting or bookkeeping services without relying on CPA licensure or CPA-program eligibility, start with our broader professional liability guide for accountants.

Last reviewed: October 2026. General educational information only—not legal, tax or insurance advice. Coverage varies by insurer, form, endorsement, state and facts of a claim.

What does CPA professional liability insurance cover?

A policy may help pay covered legal-defense costs, settlements and judgments when a client or another party alleges that the firm’s professional service caused a financial loss. A claim can be costly even when the firm believes its work was correct. The policy may also include selected extensions for subpoenas, disciplinary proceedings, crisis response or loss-prevention support.

How does the AICPA Professional Liability Insurance Program fit?

The AICPA-endorsed Professional Liability Insurance Program is one option for eligible CPA firms, not a universal policy form or an automatic best fit. The official program page states that the coverage is underwritten by CNA and offers different paths for smaller and mid-sized firms. Its published eligibility guide separates firms with three or fewer staff and less than $400,000 in annual revenue from firms with four or more staff or at least $400,000 in revenue. At least one owner or employee must be a licensed CPA. Eligibility, underwriting and policy terms can change, so confirm the current rules directly with the program administrator.

Independent comparison note: Small Business Insured is not affiliated with AICPA, Aon or CNA and does not sell or endorse a particular policy. Compare proposals using the same limits, deductible, retroactive date and service assumptions; then examine defense costs, consent-to-settle language, excluded services, cyber gaps and claims support.

Seven policy terms a CPA firm should compare

1. Professional-services definition. Match it line by line to engagement letters, invoices and the firm’s website.
2. Retroactive date. Work performed before this date may fall outside coverage. Protect prior acts when switching carriers.
3. Defense costs. Determine whether legal expenses reduce the liability limit and whether the deductible applies to defense.
4. Consent to settle. Review who controls settlement and what happens if the insured refuses a settlement the insurer recommends.
5. Regulatory and disciplinary matters. Identify any sublimit for state-board proceedings, subpoenas or investigations.
6. Extended reporting. Compare tail options for retirement, sale, closure or a carrier change.
7. Exclusions and endorsements. Pay particular attention to cyber/privacy, investment advice, fiduciary services, prior knowledge, intentional acts, contractual liability and services performed through another entity.

CPA E&O does not replace cyber or crime coverage

CPA firms retain tax records, Social Security numbers, payroll data, bank details and client credentials. A professional liability policy may exclude privacy events or provide only limited cyber protection. A dedicated cyber policy can address selected forensic, restoration, notification, ransomware, business-interruption and privacy-liability costs.

Firms that can initiate payments or alter payroll instructions should separately examine crime, computer-fraud, funds-transfer and social-engineering provisions. The same fraudulent email can produce different outcomes depending on whose funds were lost, how the transfer occurred and whether a verification procedure was followed.

For firms that prepare tax returns, the IRS provides Publication 5708 as a written information security plan framework. Use our tax-preparer WISP requirements checklist to connect those controls to cyber-insurance application questions.

What affects CPA professional liability insurance cost?

Price is driven by the firm’s risk profile, not the CPA designation alone. Important factors include gross revenue, service mix, staff count, client industries, audit and attest work, largest client size, public-company or financial-institution exposure, claims history, location, limits, deductible and prior-acts coverage.

Insureon reports an average of $42 per month for professional liability policies purchased by its finance and accounting customers, with an example average policy using a $1 million per-occurrence limit, $1 million aggregate and $1,000 deductible. That is a broad platform benchmark, not a price promise for a CPA firm. A practice with audits, complex advisory work or larger clients can differ substantially.

Information to prepare for a CPA insurance quote

• Revenue by service line for the latest year and projected year
• Number of partners, CPAs, other professionals, seasonal staff and contractors
• Client count, largest client and revenue concentration
• Audit, review, compilation, tax, advisory and other engagement counts
• Industries served and any higher-risk or regulated clients
• Prior claims, incidents, board matters and circumstances
• Current policy, retroactive date, limits and deductible
• Engagement-letter, client-acceptance and quality-control procedures
• Technology vendors, sensitive-record volume and security controls
• Mergers, acquisitions, predecessor firms, retired partners or planned ownership changes

Questions to ask before selecting a policy

• Does the professional-services definition match every service we currently provide?
• Are all firm entities, predecessor firms, partners, employees and contractors treated as intended?
• Are defense costs inside the limit, and does the deductible apply to them?
• What regulatory, subpoena and disciplinary coverage is included, and at what sublimit?
• What consent-to-settle clause applies?
• Which exclusions could affect tax, audit, advisory, valuation, fiduciary or investment-related work?
• How are cyber, privacy, fraudulent-transfer and social-engineering events handled?
• What happens to prior acts if we switch carriers?
• Which extended-reporting options are available if a partner retires or the firm closes?
• What loss-prevention resources and claims contacts are available before a formal claim is filed?

Frequently asked questions

Is CPA malpractice insurance the same as professional liability insurance?

The terms are commonly used for the same category of coverage. “Errors and omissions” is another frequent name. Compare the policy form rather than relying on the label.

Is CPA professional liability insurance legally required?

There is no universal federal requirement for every CPA firm to carry it. A state board, client contract, lender, association or other agreement may impose a requirement. Verify the rules and contracts that apply to the practice.

Does a $1 million limit mean defense costs are separate?

Not necessarily. Many professional liability policies include defense costs within the limit, which means legal fees reduce the amount remaining for a covered settlement or judgment. Read the specific form.

Does CPA E&O cover a data breach?

Do not assume it does. Review the privacy and cyber exclusions or extensions, then compare a dedicated cyber policy designed for breach response and privacy liability.

Compare quotes on equal terms: Use the free Tax & Accounting Practice Insurance Quote Worksheet to record CPA professional liability, cyber and crime limits, exclusions and policy terms before selecting a proposal.

Bottom line

CPA professional liability insurance should be built around the practice’s actual engagements, not a generic occupation label. Protect the retroactive date, compare defense and settlement terms, disclose services accurately and evaluate cyber and crime risks separately. For a broader comparison across accounting roles, read our accountant liability insurance guide.

Next steps for CPA firms

Coordinate professional liability with the cyber insurance checklist for accountants, assemble underwriting evidence with the accounting-firm evidence kit, and normalize proposals in the tax and accounting quote worksheet.

Sources

• AICPA Member Insurance Programs: Professional Liability
• CNA: Insurance for Accountants
• Insureon: Accounting Firm Insurance Costs
• IRS Publication 5708: Written Information Security Plan

Editorial note: Cost data is a source-specific benchmark, not a quote or guarantee. Sources were reviewed in October 2026. We do not receive compensation for inclusion in this guide.