The Mortality Improvement Model, MIM-2021


Longevity Advisory Group

Larry N. Stern, Chair, FSA, MAAA

Jean-Marc Fix, FSA, MAAA

Sam Gutterman, FSA, MAAA, CERA, FCAS, FCA, HonFIA

R. Dale Hall, FSA, MAAA, CERA, CFA

Thomas A. Jones, ASA, MAAA

Allen M. Klein, FSA, MAAA

Patrick David Nolan, FSA, MAAA

Laurence Pinzur, Ph.D.

Ronora Stryker, ASA, MAAA

Patrick Wiese, ASA


Research Insights - The Mortality Improvement Model, MIM-2021

Table of Contents


Report and User Guides

Research Commentary

Excel-based Tools


Questions or Comments


Different mortality projection methodologies are utilized by actuaries across applications and practice areas. As a result, the SOA’s Longevity Advisory Group (“Advisory Group”) developed a single framework to serve as a consistent base for practitioners in projecting mortality improvement.  The Mortality Improvement Model, MIM-2021, Tools and User Guides, compose the consistent approach and are defined below.

  1. A report describing MIM-2021 which summarizes the evolution of MIM-2021; provides an overview of MIM-2021; presents considerations for applying mortality assumptions in the model; and outlines issues the Advisory Group is currently considering for future model enhancements.
  2. An Excel-based tool, MIM-2021 Application Tool, and user guide, MIM-2021 Application Tool User Guide, for practitioners to construct sets of mortality improvement rates under this framework for specific applications.
  3. An Excel-based tool, MIM-2021 Data Analysis Tool, and user guide, MIM-2021 Data Analysis Tool User Guide, for practitioners to analyze the historical data sets included in the MIM-2021 Application Tool.

The Longevity Advisory Group is planning to update the framework annually as new data and enhancements become available.

Report and User Guides

Developing A Consistent Framework For Mortality Improvement

MIM-2021 Application Tool User Guide 

MIM-2021 Data Analysis Tool User Guide 

Research Commentary

Research Commentary,  The Layers of Mortality Improvement

Excel-based Tools


The Society of Actuaries does not warrant these tools as fit for use in any respect, and no warranty whatsoever should be assumed or implied by any individual of this product or its fitness for any particular purpose. Actuaries, insurers, regulators and other parties use this tool at their own risk. The SOA disclaims all responsibility for any party’s use or misuse of its tools and for any work product generated through use or misuse of the tools.

By accepting, I acknowledge that I have read and understand the above disclaimer language. (User needs to accept before downloading one or both tools. )

MIM-2021 Application Tool AGREE (Download Tool) | DISAGREE

MIM-2021 Data Analysis Tool AGREE (Download Tool) | DISAGREE


Mary Bahna-Nolan, FSA, MAAA, CERA

James Berberian, ASA, EA, MAAA, FCA

Kevin Mark Bye Jr, ASA

Timothy D. Morant, FSA, MAAA

Marianne Purushotham, FSA, MAAA

Linn K. Richardson, FSA, MAAA, CERA

Manuel S. Santos, FSA, FCIA

George Silos, FSA, MAAA, CERA

Joel C. Sklar, ASA, MAAA

Jim Toole, FSA, MAAA, CERA

At the Society of Actuaries:

Cynthia MacDonald, FSA, MAAA, Sr. Experience Studies Actuary

Jan Schuh, Sr. Research Administrator

Questions or Comments?

Give us your feedback! Take a short survey on this report. Take Survey

If you have comments, ideas for future enhancements to MIM-2021 or questions, please send an email to