HealthMod is a large research programme that brings together scientists, policymakers, and charities interested in using economic policies to improve people's health. We particularly want to improve the health of people who experience disadvantage or discrimination in their lives, as they tend to spend much more of their lives in poor health and also die younger, and the situation has got worse over the past decade. Local and national governments make decisions on various economic policies, such as changes to taxes, welfare, job creation, and social housing. These policies have long-term effects on people's health, as they influence important aspects of healthy living, like having enough money, good work, decent housing, safe neighbourhoods, and supportive communities. In HealthMod, we want to help policymakers, charity organisations and communities themselves understand how these policies affect people differently, based on characteristics like gender, income, and where they live. Our research would show whether planned new policies are likely to support long and healthy lives for everyone, or whether they would make inequalities worse. Our programme has three work areas: Computer modelling for Health: We will develop computer models to show how different kinds of policies might affect the economic situation and long-term health of each person in Britain. These models help policymakers understand the impact of policies on people in their area, especially whether they narrow or widen unfair health inequalities, so they can make informed decisions. All models we develop will be freely available for researchers and policymakers to use. Policy and Advocacy Engagement: Government organisations and charities seeking to promote healthier policy decisions are partners in our programme. Together we will decide on the most urgent questions that our modelling can help answer. This will ensure that the models we build can inform real decisions. We will create websites, videos, and training courses to explain how our models work and how to use them effectively. Citizen's Engagement and Democratisation of Modelling: We believe it is vital to involve people who may be affected by economic policies. We will host workshops where individuals experiencing issues such as poverty or poor health can share their thoughts and experiences. These insights will shape our models, making them more relevant and inclusive. We will also work with a broader group of citizens to understand which policy outcomes are most important for society. Our goal is to create high-quality, trustworthy computer models that incorporate policymaker and community perspectives. This research will guide the best way to design, explain and use computer modelling for policy decisions that seek to improve health and reduce health inequalities.