CMI Working Paper 211

CMI Working Paper 211 is issued alongside the updated version of the CMI Mortality Projections Model, CMI_2025

A frequently asked questions (FAQ) page on CMI_2025 has also been issued and is publicly available alongside this paper. It provides a brief overview of mortality improvements and the latest version of the Model. 

The latest version of the Model is calibrated to England & Wales population mortality data up to 31 December 2025.

Core projections generated by CMI_2025 produce cohort life expectancies that are higher than those produced by CMI_2024 (with other parameters held constant) for all ages for both males and females. 

Working Paper 211 contains numerical results from CMI_2025 and commentary. It also contains analysis of recent mortality in the general population and illustrations of the sensitivity of the Model to new data. 

Working Paper 211 includes additional analysis of three changes in method we considered in detail.  Our review of these aspects has not led to any changes for the Core version of CMI_2025. However, these are subjective decisions and we do not rule out the possibility of changing our approach in future versions of the Model.

The data used to calibrate CMI_2025 is based on dates when deaths were registered. Results based on the dates when deaths occurred will differ. Appendix 8 of Working Paper 211 considers changes in registration patterns and how results might differ if CMI_2025 were calibrated to data based on dates when deaths occurred.

The Model is accompanied by a methods paper, containing technical details of the calculations, and a user guide, describing how to use the software. Three additional spreadsheets have been released:

• Two spreadsheets show the derivation of the CMI_2025 dataset for males and females. 
• A spreadsheet that includes the values used in the charts in the results working paper. 

The software has been tested and found to work properly using Excel 365 in a Windows environment. If you see a yellow banner in Excel with buttons saying e.g. ‘Enable Editing’ or ‘Enable Content’ then you will need to click on these buttons in order to run the software. If however you see a red banner and the button to proceed is disabled preventing you from running the software than please let us know at projections@cmilimited.co.uk.

Documents

• CMI Working Paper 211
• Frequently asked questions (FAQs)
• CMI_2025 methods
• CMI_2025 software user guide
• The updated Model, CMI_2025
• Derivation of the CMI_2025 male dataset
• Derivation of the CMI_2025 female dataset
• Spreadsheet of values used in chart in Working Paper 211
• CMI MPC March 2026 webinar registration document

Note
The previous versions of the CMI Mortality Projections Model can all be accessed here.