Are money market account rates fixed?

No. Money market account rates are variable, meaning the bank can raise or lower them over time in response to broader interest-rate conditions and its own business decisions.

What is a tiered interest rate?

A tiered rate structure pays a higher interest rate as your account balance crosses set thresholds — for example, a higher rate might apply only to the portion of your balance above a certain amount.

What is APY and why does it matter?

APY, or annual percentage yield, reflects the total interest you’d earn in a year including the effect of compounding. It is the standard figure for comparing accounts, since it accounts for how often interest is credited.

Why do online banks often pay more?

Online banks typically have lower overhead than banks with extensive branch networks, and many pass some of those savings on to depositors through more competitive interest rates.

Can a money market account rate drop after I open the account?

Yes. Because rates are variable, a bank can lower the rate on an existing account, sometimes without much advance notice beyond what’s disclosed in the account agreement.

What is an introductory or promotional rate?

Some banks offer a higher rate for a limited introductory period to attract new depositors. It’s important to check what the rate reverts to afterward, since the ongoing rate may be considerably lower.

Do larger balances always earn better rates?

Often, but not universally. Tiered structures commonly reward larger balances, but some banks offer a single flat rate regardless of balance size, so it’s worth checking each account’s specific structure.

How often is interest paid on a money market account?

This varies by bank, but interest is commonly compounded daily or monthly and credited to the account monthly. Check the specific account disclosure for compounding frequency.

Does the Federal Reserve directly set money market account rates?

Not directly. The Federal Reserve sets a benchmark policy rate that influences the broader interest-rate environment, and banks then set their own deposit rates in response to that environment and their own funding needs.

How can I find the best money market account rate?

Compare current APYs across multiple banks and credit unions, paying attention to minimum balance requirements and whether any advertised rate is a temporary promotional offer.

How Money Market Account Rates Work | Imperialpedia

The interest rate on a money market account is rarely as simple as the single number advertised on a bank's homepage. Understanding how money market account rates work — including tiers, compounding, and the difference between promotional and ongoing rates — helps you compare offers accurately and avoid unpleasant surprises.

Rates Are Variable, Not Fixed

Unlike a certificate of deposit, which locks in a rate for a set term, a money market account typically carries a variable rate. The bank can adjust it up or down over time, generally in response to shifts in the broader interest-rate environment set by monetary policy and competitive pressure from other banks.

Tiered Rate Structures

Many banks use a tiered rate structure, where your interest rate depends on your account balance. A common pattern applies a modest rate to lower balances and a meaningfully higher rate once your balance crosses a set threshold. Some structures apply the higher rate only to the portion of the balance above the threshold; others apply it to the entire balance once you qualify. Always check which model a specific bank uses, since it changes your effective yield.

Balance tier (illustrative)	Typical rate pattern
Below minimum threshold	Lower or no interest
Mid-range balance	Standard advertised rate
High balance	Premium tier rate

APY vs. Stated Interest Rate

When comparing offers, focus on the annual percentage yield (APY) rather than the raw interest rate. APY incorporates the effect of compounding — how frequently interest is calculated and added to your balance — so it gives a more accurate picture of what you'll actually earn over a year. Two accounts with the same stated interest rate can have different APYs if one compounds daily and the other compounds monthly.

Why Online Banks Often Lead on Rate

Online-only banks generally carry lower operating costs than banks maintaining large branch networks, and many channel some of that savings into more competitive money market account rates. This is one reason it's worth comparing offers beyond just your primary bank, especially when shopping for the account that will hold a meaningful balance. For guidance on which situations actually call for chasing the best rate versus prioritizing other features, see when a money market account makes sense.

Promotional Rates: Read the Fine Print

A prominently advertised rate is sometimes a limited-time introductory offer. Always check what the rate reverts to after the promotional period ends, since the ongoing rate can be substantially lower than the headline figure.

How Rates Compare to Savings Accounts

Money market account rates and high-yield savings account rates often move in similar ranges, since both are variable-rate deposit products competing for the same savers. Neither category reliably beats the other at all times — see our comparison of money market account vs. savings account for a fuller picture of how the two stack up beyond just rate.

Common Mistakes

Comparing raw interest rates instead of APY across different banks.
Assuming a headline rate applies to your entire balance when a tiered structure only applies it above a threshold.
Opening an account for a promotional rate without checking the ongoing rate afterward.
Ignoring that rates can and do change after you've opened the account.

Conclusion

Money market account rates are shaped by variable pricing, tiered balance structures, and compounding — not a single fixed number. Comparing APY rather than headline rates, checking for tiers, and understanding whether a rate is promotional or ongoing are the key steps to knowing what you'll actually earn.