Understanding the Municipal Green Bond Underwriting Market
Green municipal bonds have emerged as a critical financing tool for local governments seeking to fund environmentally beneficial infrastructure. These tax-exempt securities follow the same issuance process as conventional municipal bonds but carry a green designation that certifies proceeds will fund eligible environmental projects.
Market Scale and Growth
Municipal green bond issuance has grown substantially since the first labeled green muni was issued in 2013. By 2024, green-labeled municipal issuance exceeded $20 billion annually, representing roughly 4-5% of total municipal issuance. The sector is dominated by a handful of large underwriters, but mid-tier and minority-owned firms increasingly participate as co-managers or senior managers on green deals.
What Qualifies as Green Infrastructure?
- Water and Wastewater
- Treatment plant upgrades, stormwater management systems, water recycling facilities, and lead pipe replacement programs.
- Clean Energy
- Solar installations on public buildings, microgrid deployments, energy storage, and grid modernization.
- Sustainable Transportation
- Electric bus fleets, light rail extensions, bike infrastructure, and EV charging networks.
- Green Buildings
- LEED-certified municipal facilities, energy-efficient retrofits, and net-zero public housing.
Selecting an Underwriter for Green Bonds
Municipal finance directors should evaluate underwriters on several dimensions beyond pricing:
| Criteria | Why It Matters |
|---|---|
| Green bond track record | Experience with second-party opinion providers and green frameworks reduces issuance risk |
| Distribution network | Access to ESG-focused investors can improve pricing by 5-15 basis points (the "greenium") |
| Sector expertise | Underwriters familiar with water or energy projects better structure bond covenants |
| Post-issuance reporting | Some underwriters assist with ongoing impact reporting required by green bond standards |
Key Market Participants
BofA Securities leads the market with over $10 billion in green municipal par value underwritten in 2024 across 44 deals. J.P. Morgan, RBC Capital Markets, and Morgan Stanley round out the top tier. Notably, firms like Ramirez & Co., Siebert Williams Shank, and Loop Capital bring diversity to the underwriting syndicate and have built meaningful green bond practices.
Citigroup exited the municipal bond market in Q1 2024, creating opportunities for other firms to capture its green bond market share.