US September inflation at 3.7%: the real return on cash, savings and CDs

The figure on an account statement can be intact to the last cent while purchasing power has shrunk. The US Bureau of Labor Statistics (BLS) published the September Consumer Price Index (CPI) at 8:30am Eastern Time on Wednesday 14 October 2026: the all-items index, not seasonally adjusted, rose 3.7% over the 12 months.

Now look at deposit rates. The FDIC national rates table shows that, as of 19 October 2026, the national average deposit rate for savings accounts is 0.38%. Putting the two figures side by side gives the question this article works through: at this level of inflation, do cash, savings and certificates of deposit earn or lose in real terms?

September CPI: petrol was a main driver of the rise

BLS data comes in several layers, and it is worth separating them before calculating:

• Year on year: the all-items index, not seasonally adjusted, rose 3.7%, with the index level at 336.940 (1982-84 = 100).
• Month on month: the Consumer Price Index for All Urban Consumers (CPI-U) rose 0.6% on a seasonally adjusted basis.
• Core: the index excluding food and energy rose 2.6% over 12 months.
• Energy: the petrol (gasoline) index rose 9.1% in September and accounted for more than half of the monthly all-items increase; the energy index rose 5.2% on the month, after a 2.1% rise in August.

Headline inflation is 3.7% year on year and core inflation is 2.6%. Which figure to use for a real return depends on which basket of spending you want to measure. This article uses 3.7% as the example; note that it is a not seasonally adjusted, year-on-year figure.

FDIC national average rates: as of 19 October 2026

The FDIC national rates table lists national average deposit rates, not the highest rates available in the market. As of 19 October 2026:

• Savings accounts: 0.38%
• Money market accounts: 0.63%
• Interest checking accounts: 0.07%

For certificates of deposit (CDs), the national average rates by term are:

• 1 month: 0.23%
• 3 months: 1.14%
• 6 months: 1.39%
• 12 months: 1.76%
• 24 months: 1.55%
• 36 months: 1.39%
• 48 months: 1.31%
• 60 months: 1.41%

Among the terms in the table, the 12-month CD has the highest average rate; locking money away for longer does not mean a higher rate. The table also carries a set of "national rate caps", for example 6.20% for 12-month CDs and 4.63% for savings accounts. These caps are for regulatory use and are not rates banks actually offer, so they should not be confused with them when comparing.

One formula to see purchasing power

A rough formula for the real return is: (1 + nominal rate) ÷ (1 + inflation rate) − 1. Putting in September's 3.7% year-on-year inflation gives:

1. Cash (0% interest): a real return of about −3.6%
2. Savings account (0.38%): a real return of about −3.2%
3. 12-month CD (1.76%): a real return of about −1.9%

These are rough estimates based on BLS and FDIC figures, not official numbers. All three are negative; the only difference is how much is lost. At national average rates, the real return on a 12-month CD is about 1.7 percentage points higher than on cash, but it still does not keep up with inflation.

High-yield savings accounts: use your own rate

This article could not verify quoted rates for high-yield savings accounts and the best CDs on the market against an official source, so it gives no specific figures. The FDIC's 0.38% is a national average and does not represent the level of high-yield accounts.

The method is simple: look up the actual annual rate on your own account or CD, put it into the formula above, and compare it with 3.7%. If the nominal rate is below inflation, the real return is negative; only a rate above inflation truly preserves purchasing power.

Limits to know before calculating

• 3.7% is inflation over the past twelve months; a CD locks in a future rate, so the purchasing power at maturity depends on inflation to come.
• The rates in this article are as of 19 October 2026; before depositing, rely on the bank's quoted rate at the time.
• The calculations do not account for tax on interest; if needed, consult a licensed tax professional.
• This article provides general information only and does not recommend any bank or product.

The next date to watch

BLS is scheduled to publish the October CPI at 8:30am Eastern Time on 10 November 2026. Put the new year-on-year figure into the same formula to see how the real return on your savings has changed relative to inflation. Look at inflation before you look at interest rates.

Prices and details correct as of October 2026

This article is general information, not investment, tax or insurance advice. Everyone’s circumstances differ; consult a licensed professional before making decisions.