IRS Publication 6031 – In the world of federal tax compliance, understanding the tax gap is crucial for policymakers, tax professionals, and everyday taxpayers. Released in October 2024, IRS Publication 6031 provides a detailed blueprint for projecting the nation’s tax gap—the difference between taxes legally owed and those paid voluntarily and on time. Titled Federal Tax Compliance Research: Tax Gap Projections Methodology, this publication focuses on Tax Years (TY) 2020, 2021, and 2022, offering insights into how the IRS models these projections amid evolving economic conditions.
Whether you’re a CPA navigating audit risks, a business owner tracking compliance, or simply curious about U.S. tax revenue shortfalls, Pub 6031 demystifies the science behind these figures. In this comprehensive guide, we’ll break down its methodology, key components, data sources, limitations, and real-world implications—optimized for those searching “IRS tax gap projections,” “tax gap methodology,” or “federal tax compliance research.”
What Is the Tax Gap? A Quick Primer?
The tax gap represents unpaid taxes due to nonfiling, underreporting, and underpayment. The IRS distinguishes between:
- Gross Tax Gap: Taxes owed but not paid voluntarily and timely.
- Net Tax Gap: The gross gap minus enforced collections and late payments.
For TY 2022, Pub 6031 underpins projections showing a gross tax gap of $696 billion (down slightly from revised TY 2021 figures) and a net tax gap of $606 billion. The voluntary compliance rate (VCR) held steady at 85.0%, meaning 85 cents of every tax dollar was paid on time without enforcement.
These aren’t just numbers—they highlight systemic issues like income visibility (e.g., wages are 99% compliant due to withholding, while sole proprietorship income sees 55% misreporting).
Why “Projections” Instead of “Estimates”? The Need for Timely Insights?
Full tax gap estimates rely on comprehensive compliance data from audits, which can take years to collect. To bridge this gap, Pub 6031 introduces projections for recent years:
- They assume constant compliance rates from the last detailed estimates (TY 2014–2016).
- This allows the IRS to capture economic growth while flagging when behavior shifts.
Key Difference from Estimates:
| Aspect | Estimates (e.g., TY 2014–2016) | Projections (TY 2020–2022) |
|---|---|---|
| Data Basis | Actual compliance studies (e.g., NRP audits) | Growth in reported tax + historical rates |
| Timing | Lags 5–8 years | More current, updated annually |
| Purpose | Measure true behavior | Bridge to next estimates; inform policy |
This approach ensures projections “reflect the level of the tax gap assuming compliance behavior has not changed from prior years.”
Core Components of the Tax Gap in Pub 6031
Pub 6031 breaks the tax gap into three pillars, with tailored methodologies:
1. Nonfiling Tax Gap (9% of Gross Gap)
- What It Covers: Taxes from individuals, self-employed, and estates who don’t file on time.
- Methodology:
- Individual & Self-Employment: “Administrative Data Method” using IRS info documents and imputed demographics from Census data. Subtracts timely payments.
- Estate Tax: Late filers’ reported liability minus payments.
- TY 2022 Projection: $63 billion ($53B individual, $9B self-employment, $1B estate).
2. Underreporting Tax Gap (77% of Gross Gap)
- The largest component, focusing on understated income/deductions on timely returns.
- Breakdown by Tax Type (TY 2022):
Tax Type Projection ($B) % of Gross Gap Individual Income 381 55% Employment (FICA/FUTA) 111 16% Corporation 44 6% Estate 2 <0.5% - Key Methods:
- Line-Item Level for Individuals: Applies TY 2014–2016 compliance rates to reported amounts; grows tax gap with absolute reported values.
- Corporations: Voluntary Reporting Rates (VRR) from audits (small: assets <$10M; large: ≥$10M) scaled by reported tax growth.
- Detection Controlled Estimation (DCE): Adjusts for undetected noncompliance, inflating estimates 2–4x for individuals.
Visibility Effect: Misreporting drops dramatically with third-party reporting—1% for wages vs. 55% for nonfarm sole proprietors.
3. Underpayment Tax Gap (14% of Gross Gap)
- Reported but unpaid taxes.
- Methodology: Direct tabulation from IRS systems, adjusted for employer underdeposits.
- TY 2022: $94 billion (mostly individual income at $80B).
4. Enforced and Other Late Payments
- Subtracts IRS collections and voluntary late payments to get the net gap.
- Projection: Based on historical payment flows (FY 1995–2020 data); updated for underpayment-late payment correlations.
- TY 2022: $90 billion recovered, yielding $606B net gap.
Data Sources Powering the Projections
Pub 6031 draws from trusted IRS systems:
- Individual Returns Transaction File (IRTF): For underreporting.
- Business Returns Transaction File (BRTF): Corporations and employment taxes.
- National Research Program (NRP): Audit-based compliance rates.
- Administrative Data: Master File tabulations for payments.
- External: Census for nonfiling demographics.
Table 1 from Pub 6031 summarizes approaches (excerpted above).
Limitations and Challenges: What Pub 6031 Acknowledges
No methodology is perfect. Pub 6031 transparently details four error types for individual underreporting (the biggest slice):
- Sampling Error: Small high-income samples may miss skewed noncompliance.
- Measurement Error: DCE helps, but flow-through entities and offshore accounts remain hard to detect.
- Estimation Error: Adjustments can bias top earners.
- Coverage Error: Excludes digital assets, illegal income, certain COVID credits, and full corporation/excise gaps.
Projection Error: Assumes static rates—if compliance improves (e.g., via IRA funding), actual gaps shrink.
The IRS is “actively working on new methods” for emerging issues like crypto.
Real-World Impact: TY 2022 Projections in Context
- Economy Tie-In: Tax gap grew with GDP (9% from 2021–2022), but VCR stayed flat at ~85%.
- By Tax Type VCR:
Tax Type VCR Individual 80% Corporation 87% Employment 92% Estate 87%
These inform IRS priorities: High-income audits, information reporting expansions.
Why Pub 6031 Matters for You?
For taxpayers: Highlights high-risk areas (e.g., self-employment, deductions). For professionals: Guides risk assessment. For policymakers: Supports funding decisions—e.g., Inflation Reduction Act boosted enforcement, potentially closing gaps over time.
Download It: IRS Publication 6031 PDF.
FAQs About IRS Publication 6031 and Tax Gap Projections
Q: When will full estimates for TY 2022 be available?
A: Fall 2025 (delayed per IRS schedule). Projections fill the interim.
Q: How does the tax gap affect the federal budget?
A: A 1% VCR increase could add ~$46 billion annually.
Q: Are projections reliable?
A: Yes, but subject to revision as data arrives—TY 2020–2021 were updated in 2024.
Q: What’s next for tax gap research?
A: IRS focuses on digital assets, flow-throughs, and AI-driven audits.
Stay compliant and informed—subscribe to IRS updates or consult a tax advisor. For more on federal tax compliance, explore related pubs like Tax Gap Projections (Pub 5869).
Last Updated: February 2026. All data from official IRS sources.