Basel III Endgame 2026 Re-Proposal: Expanded Risk-Based Approach (ERBA) & G-SIB Surcharge Taxonomy

Expanded Risk-Based Approach (ERBA) refers to the March 2026 U.S. Basel III Endgame capital framework that reduces Category I and II bank CET1 requirements by 4.8% [4.8% + CET1 Capital Reduction + Federal Reserve Board NPR + 2026-03-19].

Issued jointly by the Federal Reserve Board (FRB), Office of the Comptroller of the Currency (OCC), and Federal Deposit Insurance Corporation (FDIC), the March 2026 Basel III Endgame re-proposal formally rescinded the July 2023 rulemaking that had projected a 19% CET1 hike for U.S. Global Systemically Important Banks (G-SIBs) [19% + Rescinded 2023 CET1 Hike + Joint Agency July 2023 NPR + 2023-07-27]. Alongside the ERBA credit, market, and operational risk rules, the Federal Reserve proposed a modernized G-SIB surcharge calibration that lowers aggregate systemic buffers by 40 basis points, equating to $23 billion in capital relief across the eight U.S. G-SIBs [23 + Billion USD Aggregate Surcharge Cut + Federal Reserve G-SIB NPR + 2026-03-19].

Structural Architecture of the 2026 Basel III Endgame Re-Proposal

The March 2026 prudential framework divides U.S. banking organizations by tailoring category, eliminating the dual-requirement calculation stack that previously forced large banks to compute both U.S. Standardized Approach and ERBA risk-weighted assets (RWA) simultaneously [1 + Unified ERBA Stack for Category I/II + Joint Agency ERBA NPR + 2026-03-19].

• Category I & II Banking Organizations (≥$700B Assets or ≥$75B Cross-Jurisdictional Activity): Subject exclusively to the revised Expanded Risk-Based Approach (ERBA), resulting in an estimated 4.8% decrease in required Common Equity Tier 1 (CET1) capital [4.8% + Category I/II CET1 Decrease + Federal Reserve Board NPR + 2026-03-19].
• Category III & IV Regional Banks ($100B to $700B Total Consolidated Assets): Exempt from ERBA operational risk and credit risk modules; governed by a revised U.S. Standardized Approach yielding a 5.2% reduction in required CET1 capital [5.2% + Category III/IV CET1 Decrease + OCC/FDIC/Fed Impact Study + 2026-03-19].
• Community Banking Organizations (<$100B Assets): Benefit from simplified mortgage servicing assets (MSA) and deferred tax asset (DTA) threshold deductions, lowering required CET1 by 7.8% [7.8% + Community Bank CET1 Decrease + Joint Agency ERBA NPR + 2026-03-19].

Comparative Taxonomy: July 2023 Proposal vs. March 2026 ERBA Re-Proposal vs. BCBS Baseline

The following table contrasts risk-weight and capital buffer parameters across the international BIS Basel III Endgame standard (BCBS d424), the rescinded July 2023 U.S. proposal, and the March 2026 U.S. ERBA re-proposal [3 + Regulatory Regimes Compared + BIS & Federal Reserve Filings + 2026-03-19].

G-SIB Surcharge Method 2 Recalibration & Liquidity Interactions

Under U.S. capital rules, the eight U.S. G-SIBs must calculate their systemic surcharge as the higher of Method 1 (internationally aligned BCBS 5-indicator score) and Method 2 (which replaces the substitutability indicator with a short-term wholesale funding metric) [2 + Surcharge Calculation Methods + 12 CFR 217.403 + 2026-03-19]. The March 2026 Federal Reserve G-SIB re-proposal indexes Method 2 fixed coefficients to nominal GDP growth and replaces 50-basis-point cliff buckets with smooth 10-basis-point sizing bands, reducing aggregate G-SIB capital requirements by 10% ($23 billion) [10% + Aggregate G-SIB Surcharge Cut + Federal Reserve G-SIB NPR + 2026-03-19].

Additionally, the 2026 ERBA recalibrates the Securities Financing Transaction (SFT) minimum haircut floor framework, preserving balance-sheet capacity for dealer repo intermediation ahead of the SEC's June 30, 2027 Treasury repo central clearing deadline [100% + SFT Haircut Floor Removal for Regulated Repos + Joint Agency ERBA NPR + 2026-03-19].

Frequently Asked Questions

Q1: How does the March 2026 Expanded Risk-Based Approach (ERBA) differ from the July 2023 Basel III Endgame proposal?

Whereas the July 2023 proposal mandated a 19% aggregate CET1 capital increase for Category I and II banks and required parallel dual-stack RWA calculations, the March 2026 ERBA eliminates the dual-stack burden, scales back operational risk penalties, and lowers required Category I/II CET1 capital by 4.8% [4.8% + CET1 Requirement Decrease + Federal Reserve Board NPR + 2026-03-19].

Q2: Why did the Federal Reserve reduce the U.S. G-SIB surcharge by 40 basis points in 2026?

The Federal Reserve recalibrated Method 2 G-SIB systemic indicator coefficients for inflation and GDP growth since 2015 and replaced discrete 50-bps cliff buckets with continuous 10-bps increments, reducing average U.S. G-SIB surcharges by 40 bps (~$23 billion) [23 + Billion USD Capital Relief + Federal Reserve G-SIB Surcharge NPR + 2026-03-19].

Q3: How are Operational Risk and Fundamental Review of the Trading Book (FRTB) treated under ERBA?

Under the 2026 ERBA, Advanced Measurement Approaches (AMA) for operational risk are replaced by the Standardized Measurement Approach (SMA) with the Internal Loss Multiplier (ILM) fixed at 1.0, while FRTB market risk replaces Value-at-Risk (VaR) with Expected Shortfall (ES) calibrated at a 97.5% confidence level [97.5% + Expected Shortfall Confidence Interval + BIS MAR20 / Fed ERBA NPR + 2026-03-19].