Browse Investing
Series Bonds
Series bonds are issued in groups with different maturities, rates, or terms under the same financing program.
Series bonds are bonds issued in separate groups, often under the same financing program, bond resolution, indenture, or issuer plan. Each series can have its own issue date, maturity schedule, interest rates, call features, tax status, or project purpose.
The term “series” is about grouping and program structure. It is not the same as a Serial Bond, which is about staggered maturities.
Core Idea
A financing program can issue multiple series over time.
For example, a city, agency, or corporation may issue Series 2026A for one project phase and Series 2026B for another. Each series may contain serial maturities, term bonds, sinking fund requirements, or different coupons.
Why It Matters
Series bonds matter because the label can hide important differences inside the same issuer program.
They can differ by:
- issue date and pricing date
- project or use of proceeds
- maturity schedule
- coupon rates and yields
- tax status
- security pledge or revenue source
- call protection and redemption provisions
- seniority, covenants, or reserve funds
Two series from the same issuer are not automatically interchangeable. Investors should compare the actual series terms.
Practical Example
Suppose a transit authority funds a multi-year project through several series:
| Series | Possible purpose | Why it matters |
|---|---|---|
| Series 2026A | Track construction | May have one maturity schedule and pledge |
| Series 2026B | Station improvements | May price later in a different rate environment |
| Series 2027A | Equipment financing | May have shorter average life or different covenants |
All three may belong to the same program, but each series can have different yield, duration, liquidity, tax treatment, and security features.
Series Bonds vs. Related Labels
| Label | What it describes | Best use | Main caution |
|---|---|---|---|
| Series bonds | Separate groups under a financing program or indenture | Comparing different issue groups from the same issuer | Each series can have different terms |
| Serial Bond | Maturity schedule with staggered principal repayment | Maturity-ladder and debt-service analysis | Not the same as series grouping |
| Term Bond | One maturity block, often with sinking fund provisions | Concentrated maturity analysis | May sit inside a larger series |
| Bond Indenture | Legal contract governing bond terms | Source for series and covenant details | Must read supplements and amendments |
The safest reading is document-first: identify the series, then read the terms that apply to that series.
What To Verify
Before relying on a series-bond label, verify:
- series name, date, CUSIPs, issue size, and maturity schedule
- whether the series is taxable, tax-exempt, green, social, revenue-backed, GO-backed, secured, or unsecured
- use of proceeds and project phase
- coupon, yield, price, and redemption terms by maturity
- whether the series shares collateral or revenue with other series
- seniority, parity debt, cross-default, reserve fund, and covenant terms
- official statement, supplemental indenture, continuing disclosure, and ratings
- whether another series from the same issuer has different legal or economic terms
The issuer name alone is not enough. Series-level terms can drive pricing and risk.
Public Source Checks
Useful public references include:
- MSRB Buying and Selling Municipal Bonds: Explains official statements, EMMA, trade prices, ratings, and disclosure documents for municipal securities.
- MSRB Municipal Bond Basics: Explains municipal bond structures, serial bonds, term bonds, and sinking funds.
- SEC What Are Municipal Bonds: Investor education on municipal bond issuers, proceeds, interest, principal, and disclosure.
- Investor.gov Corporate Bonds: Investor education on bond maturities, secured bonds, call features, and corporate debt terms.
These sources support the public bond-structure context. A series-specific conclusion still requires the official statement, indenture, supplement, pricing data, and current disclosure records.
Related Terms
- Serial Bond: Maturity schedule concept often confused with series bonds.
- Bond Indenture: Legal source for series-level terms.
- Coupon Rate: Rate term that can vary by maturity or series.
- Maturity Date: Date when principal is due for a specific maturity.
- Sinking Fund Provisions: Redemption provisions that may apply to term maturities inside a series.
- Municipal Bond: Common market where series labels appear.