The stages of change model is a framework that describes behavior change as a process people move through in six distinct phases, from having no awareness of a problem to fully leaving it behind. Developed by psychologists James Prochaska and Carlo DiClemente in the late 1970s and 1980s, the model grew out of research on smoking cessation. What made it unique was that the researchers didn’t just study people in formal treatment programs. They also studied smokers who quit on their own, and those self-changers helped the researchers identify the specific stages and tasks that predicted success.
The model’s formal name is the Transtheoretical Model of Change (TTM), so called because it pulls ideas from multiple psychological theories rather than belonging to just one. It has since been applied far beyond smoking to exercise, diet, addiction recovery, medication adherence, and other health behaviors.
The Six Stages
Each stage reflects a different level of readiness and commitment. People don’t necessarily move through them in a straight line. Relapse is common, and most people cycle through the stages more than once before a change sticks.
Precontemplation
At this point, you have no intention of changing. You may not see the behavior as a problem at all, or you may feel that the costs of changing outweigh the benefits. Someone in precontemplation might get defensive when others bring up the behavior. The key characteristic here is a lack of awareness or a sense that change isn’t worth it.
Contemplation
You recognize the problem and are thinking about doing something about it, but you haven’t committed to a plan. This stage is defined by ambivalence: you’re weighing the pros and cons of your current behavior against the benefits and barriers of changing. People can stay stuck in contemplation for a long time, sometimes years. Motivational interviewing, a counseling style that helps people explore their own reasons for change, is often used to help people work through this ambivalence.
Preparation
You intend to take action soon and have started taking small steps. Maybe you’ve set a quit date, signed up for a gym membership, or told someone about your plan. Your determination is increasing, and you may be experimenting with minor adjustments to your routine. This is where concrete planning happens: identifying triggers, building a support system, and deciding on specific strategies. Cognitive-behavioral approaches, like learning coping skills and rearranging your environment to reduce temptation, fit naturally into this stage.
Action
You’ve made a visible change to your behavior. This is the most demanding stage in terms of time and energy. In the TTM framework, you’re considered to be in the action stage for roughly the first six months after making the change. The risk of slipping back is highest here because the new behavior hasn’t become routine yet.
Maintenance
The new behavior has been sustained long enough that it’s becoming part of your life, but you still need to actively work to prevent relapse. Maintenance can last anywhere from six months to several years. The strategies shift from making the change to protecting it: avoiding high-risk situations, rewarding yourself for staying on track, and leaning on supportive relationships.
Termination
You have no desire to return to the old behavior, and it takes zero effort to maintain the change. Not everyone reaches this stage, and some researchers question whether it’s realistic for certain behaviors like addiction, where some level of vigilance may always be necessary.
The 10 Processes That Drive Change
The stages describe where someone is. The processes describe how they move forward. Prochaska and DiClemente identified 10 processes of change, which fall into two broad categories: thinking-based processes that tend to matter more in the earlier stages, and action-based processes that become more important once you’re actively changing behavior.
The thinking-based processes include:
- Consciousness raising: Seeking new information about the problem, like reading about the health effects of smoking or tracking how much you drink in a week.
- Dramatic relief: Experiencing strong emotions related to the behavior, whether that’s fear after a health scare or hope after watching someone else succeed.
- Environmental reevaluation: Recognizing how your behavior affects the people and world around you, not just yourself.
- Self-reevaluation: Rethinking your values and self-image in light of the behavior. This is the moment someone starts to see themselves as a nonsmoker rather than a smoker who is trying to quit.
- Social liberation: Noticing that society supports the change you’re considering, like smoke-free buildings or the availability of healthier food options.
The action-based processes include:
- Counterconditioning: Replacing the problem behavior with a healthier alternative, like going for a walk instead of reaching for a cigarette.
- Helping relationships: Building trust with people who support your change, whether friends, family, or a counselor.
- Reinforcement management: Rewarding yourself for progress. This can be as simple as treating yourself to something you enjoy after hitting a milestone.
- Self-liberation: Making a firm commitment and believing you can follow through. New Year’s resolutions are a familiar (if imperfect) example.
- Stimulus control: Restructuring your environment to reduce triggers. If you’re trying to eat less junk food, you stop keeping it in the house.
The practical value of matching processes to stages is that it helps explain why certain approaches fail. Jumping straight to action-based strategies with someone who hasn’t even acknowledged the problem (precontemplation) is unlikely to work. That person first needs information and emotional engagement, not a behavior plan.
How the Model Is Used in Practice
Clinicians and health coaches use the stages of change model primarily as an assessment tool. Rather than treating every person the same way, they first figure out which stage someone is in and then match their approach accordingly. Two simple tools mentioned in clinical literature are the Readiness to Change Ruler, which asks people to rate their motivation on a scale, and the Agenda-Setting Chart, which opens a conversation about what the person is and isn’t willing to discuss.
The goal of any single interaction isn’t necessarily to get someone to change their behavior on the spot. It’s to help them move one stage forward. For someone in precontemplation, success might look like simply agreeing that the behavior is worth thinking about. For someone in preparation, it might mean finalizing a specific plan with a start date.
The model has been applied to a wide range of behaviors beyond its smoking cessation roots: physical activity, alcohol and drug use, diet, medication adherence, safe sex practices, and even organizational change. A 2020 quasi-experimental study of 200 rural smokers found that a TTM-based intervention significantly improved participants’ knowledge about quitting and helped them progress through the stages over six months, though it did not directly reduce the number of cigarettes smoked or lower nicotine dependence scores. That finding captures both the model’s strength (helping people move toward readiness) and its limitation (readiness alone doesn’t guarantee results).
Criticisms and Limitations
The stages of change model is widely taught and widely used, but it has also faced significant scientific criticism. The core concern is that the stages may not reflect real, qualitatively different states. Instead, critics argue, behavior change is a continuous process that the model artificially divides into categories.
Several specific issues have been raised in peer-reviewed critiques. The stages are supposed to be mutually exclusive, meaning a person is in only one stage at a time, but research suggests the boundaries are blurry. People often show characteristics of multiple stages simultaneously. Longitudinal studies have tracked more than 400 different patterns of movement between stages, and no study has documented a single person moving through the entire sequence from precontemplation to termination in order. The neat, stepwise progression the model describes doesn’t match what researchers observe in real data.
There are also measurement problems. The questionnaires used to classify people into stages aren’t consistent across studies. Different researchers use different time frames and different wording, which means shifting those reference points changes how many people end up in each stage. These aren’t minor technical details. They raise the question of whether the stages are capturing something real about human psychology or just sorting people into convenient but somewhat arbitrary groups.
Perhaps the broadest critique is that the model claims to apply universally across behaviors, populations, and situations, but the evidence doesn’t consistently support that. What drives someone to quit smoking may look very different from what drives someone to start exercising, and a one-size-fits-all stage framework may smooth over those important differences.
None of this means the model is useless. Its core insight, that people at different levels of readiness need different kinds of support, remains practical and intuitive. But it’s best understood as a useful clinical heuristic rather than a precise scientific law.