Maryland Security Deposit Interest Rate: Every Year's Rate and How the Math Works

Every January, the number changes. Maryland ties its security deposit interest rate to the 1-year U.S. Treasury yield, so the rate a landlord owes is not one number but a stack of them: one per calendar year the deposit was held. Return a deposit after a five-year tenancy and the payout spans five different rates, each applied month by month.

This post is the reference for that stack: the current rate, the complete table back to 2015, exactly how the monthly math works, and a worked example you can check against the state's own calculator.

The Complete Rate Table, 2015 to 2026

Maryland rewrote the interest formula effective January 1, 2015. Since then, RP § 8-203(e) sets each calendar year's rate at the greater of 1.5% or the daily U.S. Treasury yield curve rate for one year, measured on the first business day of that year.

Two patterns worth noticing. First, the 1.5% floor did all the work during the low-rate years: 2015 through 2017, and again in 2021 and 2022, when the 1-year Treasury opened the year below 1.5%. Second, the 2022-to-2023 jump is enormous: a deposit's monthly interest more than tripled overnight when the rate went from 1.50% to 4.72%. Landlords who last computed deposit interest before 2023 are usually surprised by how much a current payout has grown.

Tenancies that began before 2015 accrued under the older flat regime, 3% per year (and 4% before October 2004), with different accrual rules. Everything below covers deposits paid on or after January 1, 2015.

How the Monthly Math Actually Works

The state's methodology, published by the Maryland Department of Housing and Community Development alongside its official calculator, comes down to five rules:

1. The clock starts when the deposit is paid, not when the lease begins. A deposit collected three weeks before move-in starts earning three weeks before move-in.
2. Interest accrues in monthly periods anchored to that payment date. A deposit paid on the 9th accrues in periods running the 9th through the 8th.
3. Each period earns the deposit times the annual rate of the calendar year the period begins in, prorated by the actual days in the period over a 365-day year. A period that starts in December and ends in January uses December's year.
4. Partial months earn nothing. If the tenancy ends 18 days into an accrual month, those 18 days accrue no interest.
5. No compounding. The interest is simple from first month to last.

And the two gatekeeping rules that come before any math: deposits under $50 never earn interest, and no interest at all is owed unless the landlord held the deposit for at least six months under § 8-203(e)(3).

A Worked Example, to the Penny

Take a $1,850 deposit paid on April 9, 2021, for a tenancy that ended June 27, 2026.

The deposit accrued for 62 full monthly periods, April 9 to May 8, May 9 to June 8, and so on. The 2021 and 2022 periods earned 1.5%, the 2023 periods 4.72%, the 2024 periods 4.80%, the 2025 periods 4.17%, and the 2026 periods 3.47%. The final stretch, June 9 to June 27, 2026, was a partial month and earned nothing.

Total interest: $328.72. Total due back to the tenant, absent deductions: $2,178.72.

At 1.5% alone that tenancy would have earned roughly $143, so the 2023 rate jump more than doubled the payout. That is the practical reason to compute rather than estimate: the multi-year rate stack moves real money.

You can reproduce that number two ways. The State of Maryland's official calculator at dhcd.maryland.gov computes the interest figure. Or use the free Maryland Security Deposit Calculator, which applies the same methodology, shows the full month-by-month schedule, and also generates a signable Security Deposit Return Statement with the itemized deduction list § 8-203 requires, ready to print and mail with the refund.

What You Owe at Move-Out

The interest is only half the compliance picture. Within 45 days after the tenancy ends, the landlord must return the deposit plus all accrued interest, less lawful deductions, by first-class mail to the tenant's last known address.

If anything is withheld for damages, the same 45-day window requires a written list of the damages claimed with an itemized statement of costs incurred, sent by first-class mail, with supporting receipts, invoices, or a written estimate. Miss that itemization and the right to withhold is forfeited entirely. Withhold without a reasonable basis and the tenant can recover up to three times the withheld amount plus attorney's fees.

One adjacent number that changed recently: the maximum deposit a Maryland landlord may collect is now one month's rent for leases signed on or after October 1, 2024, under the Renters' Rights and Stabilization Act. The full compliance picture, receipts, escrow accounts, deductions, and penalties, is covered in the landlord's guide to Maryland security deposit law.

Related reading:

• Maryland Security Deposit Law: The Landlord's Guide to RP § 8-203 in 2026
• Maryland's 5% Late Fee Cap: What Landlords Can Actually Charge
• The Rent Ledger That Wins in Maryland Rent Court
• Maryland's Tenants' Bill of Rights: Landlord Compliance Guide
• How to Evict a Tenant in Maryland: The Complete 2026 Guide

Returning a deposit this month? Get the exact interest figure and a signable return statement in about two minutes: