IBMR vs MUNB

IBMRAiShares iBonds Dec 2029 Term Muni Bond ETF

MUNBCNorthern Trust 2035 Tax-Exempt Distributing Ladder ETF

In short

IBMR A muni ladder rung in one ticker: it holds investment-grade municipal bonds maturing in 2029, tracks an AMT-free index, and pays monthly. Bond-style term structure, ETF plumbing.

MUNB Not a one-and-done maturity fund: MUNB packs a ten-rung municipal ladder into one ticker, paying monthly federally tax-exempt income, returning principal each year as rungs mature, then liquidating in 2035.

Stated mandate

IBMR The fund seeks to track an index of investment-grade municipal bonds that mature in 2029.

MUNB The Fund seeks periodic distributions through 2035 consisting of federally tax-exempt income and/or principal. It uses a laddered municipal-bond strategy with maturities spread across annual rungs through the terminal year.

Why people hold it

• IBMR Charges 0.10% a year, right at the median for target-maturity bond funds, and the iBonds lineup is built so maturity years stack into a ladder.
• Spreads across more than a thousand investment-grade munis, so one issuer's trouble barely moves the fund.
• Follows an AMT-free index, screening out bonds whose income can trip the alternative minimum tax.
• Pays monthly, matching how muni income is usually spent, and holds a well-built portfolio for its category.

• MUNB One ticker holds a ten-rung muni ladder running to 2035: monthly federally tax-exempt income, plus principal paid back each year as rungs mature. No rolling bonds yourself.flexshares.comnortherntrust.com
• Bonds are generally held to maturity and the proceeds distributed rather than reinvested, so the cash-flow pattern is set by the ladder itself.flexshares.com
• Actively run by Northern Trust's muni team across a few hundred bonds, with the annual rungs funded in roughly equal par amounts.flexshares.com

Worth knowing

• IBMR Munis are the tax-advantaged lane. For the same 2029 rung in taxable bonds, iShares also runs IBDU (corporate) and IBTJ (Treasury).
• The index is callable-adjusted: plenty of munis can be redeemed early by their issuers, so the mix heading into the term date can shift.
• It is a fund, not a single bond. Shares trade at market prices and move with rates along the way, and the end payout is whatever the bonds deliver.

• MUNB Runs 0.18% against a 0.10% median for target-maturity bond funds. Taxable rungs like IBTJ (0.07%) and BSCT (0.10%) cost less, but their income is not tax-exempt.
• Share price is built to grind down as principal comes back, and distributions can include return of capital, which lowers your cost basis for later.flexshares.comflexshares.com 2
• Launched in 2025, still small and thinly traded, so bid-ask spreads can be wider than in the big term-bond families.

Full IBMR profile⁠

Full MUNB profile⁠