JWST Call for Proposals for Cycle 3

STScI solicits proposals for JWST Observing, Archival, and Theoretical Research. Downloadable PDF collections of these articles are provided as a courtesy, made available and updated when feasible.

The online documentation is the authority, and will be updated with the latest information.

On this page

Late breaking news

New information that arises during the Cycle 3 Call for Proposals will be provided here.

  • Cycle 3 proposers should use the Astronomer's Proposal Tool (APT) version 2023.5.1 or higher in proposal preparation, released 24 August 2023. See the  release notes for details. 
  • Cycle 3 proposers should use the JWST Exposure Time Calculator (ETC) version 3.0, released 24 August 2023. This release features accuracy updates based on inflight measurements, updates to IFU strategies, and new instrument-specific options for Cycle 3. See the release notes for details, and be sure to review the known issues for this release. Instructions for downloading the new version of the Pandeia engine and the associated data are found in the JWST Documentation and the Pandeia Engine News page.
  • Reduced count rate in MIRI imager. The photon count rate and the derived flux of the MIRI imager are lower than what is predicted at wavelengths between 12.8 and 25.5 µm, as mentioned in this news item on August 24, 2023. The current version of the Exposure Time Calculator (ETC) does not include this effect. Users wishing to propose observations for Cycle 3 in filters F560W through F1800W can assume the SNR calculations in the ETC are sufficiently accurate (nominally, the signal-to-noise ratio goes as the square root of the count rate). For the F2100W and F2550W filters, adding margins of 5% on the signal-to-noise ratio to mitigate for the observed loss is strongly recommended. Proposals that do not follow this recommendation will not be granted supplementary time through the TTRB for inadequate exposure times and any adjustments will need to come from the TAC allocated duration.


We invite scientists to participate in Cycle 3 of the James Webb Space Telescope (JWST). The telescope and its instruments were built under the auspices of the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), and the Canadian Space Agency (CSA). Management of JWST's scientific program is carried out by the Space Telescope Science Institute (STScI). We anticipate allocating up to 5,000 hours in this cycle. In Cycle 2, the split between size categories was 2,350 hours for Small programs (≤ 25 hours), 1,750 for Medium programs (> 25 and ≤ 75 hours), and 900 for Large programs (> 75 hours). The Cycle 3 allocations are subject to adjustment based on proposal pressure. Abstracts of previously accepted programs can be found on the JWST proposal catalogs webpage.

This document establishes the goals, requirements, and policies for General Observer (GO) and Archival Research (AR) programs in Cycle 3. The table of contents for the web version of this document is on the left side of the page, and links there can take you to any page from any other page (click the arrow to expand the entire table of contents under "JWST Call for Proposals for Cycle 3"). The links at the top of each page correspond to sections within that given page.

Proposing calendar and deadlines

Cycle 3 dates: July 1, 2024 – June 30, 2025

Cycle 3 proposal deadline: October 25, 2023 by 8:00pm US Eastern Daylight Time

Cycle 3 Peer Review meeting: January 29 - February 8, 2024

Cycle 3 Budget submission deadline: April 11, 2024 by 5:00pm US Eastern Daylight Time

Notification of the outcome of the selection process will be sent to all proposers in late February/early March, 2024.

Where to get help

Who's responsible

The JWST Call for Proposals and related materials for Cycle 3 were edited by Amaya Moro-Martín. The Associate Director for Science, Neill Reid, and the Science Mission Office at STScI are responsible for the oversight of the JWST science program selection process, whose members include Alessandra Aloisi (Head of Science Mission Office), Christine Chen (Head of James Webb Space Telescope Science Policies Group), Katey Alatalo, Andrew Fruchter, Claus Leitherer, Amaya Moro-Martín, Jamila Pegues, Elena Sabbi, Linda Smith, Laura Watkins, and Technical Manager Brett Blacker.

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Notable updates

Originally published