Source: Board of Governors of the Federal Reserve System (US)  

Release: H.4.1 Factors Affecting Reserve Balances  

Units:  Billions of U.S. Dollars, Not Seasonally Adjusted

Frequency:  Weekly, Ending Wednesday

Feb 1984 - Dec 1990: Annual Statistical Digest, various issues, Table 2.
Jan 1991 to date: Federal Reserve Board, H.4.1.
Reserve balances with Federal Reserve Banks are the difference between "total factors supplying reserve funds" and "total factors, other than reserve balances, absorbing reserve funds." This item includes balances at the Federal Reserve of all depository institutions that are used to satisfy reserve requirements and balances held in excess of balance requirements. It excludes reserves held in the form of cash in bank vaults, and excludes service-related deposits

Source: Board of Governors of the Federal Reserve System (US)  

Release: H.6 Money Stock Measures  

Units:  Billions of Dollars, Not Seasonally Adjusted

Frequency:  Monthly

Before May 2020, M2 consists of M1 plus (1) savings deposits (including money market deposit accounts); (2) small-denomination time deposits (time deposits in amounts of less than $100,000) less individual retirement account (IRA) and Keogh balances at depository institutions; and (3) balances in retail money market funds (MMFs) less IRA and Keogh balances at MMFs.

Beginning May 2020, M2 consists of M1 plus (1) small-denomination time deposits (time deposits in amounts of less than $100,000) less IRA and Keogh balances at depository institutions; and (2) balances in retail MMFs less IRA and Keogh balances at MMFs. Seasonally adjusted M2 is constructed by summing savings deposits (before May 2020), small-denomination time deposits, and retail MMFs, each seasonally adjusted separately, and adding this result to seasonally adjusted M1.

For more information on the H.6 release changes and the regulatory amendment that led to the creation of the other liquid deposits component and its inclusion in the M1 monetary aggregate, see the H.6 announcements and Technical Q&As posted on December 17, 2020.

For questions on the data, please contact the data source. For questions on FRED functionality, please contact us here.

Source: Board of Governors of the Federal Reserve System (US)  

Release: H.4.1 Factors Affecting Reserve Balances (data not included in press release)

Units:  Billions of Dollars, Not Seasonally Adjusted

Frequency:  Monthly

Data prior to 1991 are from various issues of Banking and Monetary Statistics and the Annual Statistical Digest. Data from 1991 forward are calculated using data from the H.4.1 Release - Factors Affecting Reserve Balances.
As of March 1, 2019, this series is calculated as a monthly average of fred.stlouisfed.org/series/WCURCIR.

Source: Federal Reserve Bank of St. Louis  

Release: St. Louis Monthly Reserves and Monetary Base  

Units:  Billions of Dollars, Seasonally Adjusted

Frequency:  Monthly

Updates of this series will be ceased on December 20, 2019. Interested users can access the not seasonally adjusted version of this series from the H.3 release, BOGMBASE.
For more details, see the FRED Announcement.

Source: Board of Governors of the Federal Reserve System (US)  

Release: H.3 Aggregate Reserves of Depository Institutions and the Monetary Base  

Units:  Billions of Dollars, Not Seasonally Adjusted

Frequency:  Monthly

The Board of Governors discontinued the H.3 statistical release on September 17, 2020. For more information, please see the announcement posted on August 20, 2020.

Total reserve balances maintained is the amount of balances institutions hold in accounts at Federal Reserve Banks that are available to satisfy reserve requirements. Historically, this series excluded balances held in a reserve account for contractual clearing purposes (contractual clearing balances program has been discontinued on July 12, 2012).