If you have ever printed out your continuous glucose monitor (CGM) data or pulled it up in an app and felt like you were staring at a wall of numbers and squiggly lines, you are in very good company. The Ambulatory Glucose Profile, usually just called the AGP report, is meant to turn weeks of glucose readings into a single, standardized snapshot. Once you know what each part is telling you, that intimidating page becomes one of the most useful tools you have for understanding your own patterns and having a productive conversation with your care team.
This guide walks through the AGP report section by section, in plain language, so you can read your own report with confidence and know which parts are worth flagging at your next appointment.
The AGP at a Glance: What Each Section Means
Most AGP reports follow the same layout no matter which device or software generated them, because a group of diabetes experts agreed on a standard format so everyone would be looking at data the same way. Here are the core pieces you will find on almost every report:
- Glucose Statistics and Targets: A summary box at the top with your average glucose, how many days of data are included, and how much of the time your sensor was actively collecting readings.
- Time in Ranges: A colored bar showing what percentage of the time your glucose was low, in target, or high.
- Glucose Management Indicator (GMI): An estimate of what your A1C might be, based on your average CGM glucose.
- Glucose Variability: A percentage that describes how much your glucose swings up and down.
- The AGP Graph: A single 24-hour picture that layers all your days together to reveal your typical daily pattern.
- Daily Glucose Profiles: A calendar-style set of small graphs, one per day, so you can spot specific days that stood out.
The American Diabetes Association and the international group behind the standard recommend looking at roughly 14 days of data for the report to be meaningful, and ideally with the sensor active at least 70 percent of that time. If your report covers only a handful of days, the patterns may not yet be reliable enough to make big changes from.
Time in Range: The Number Worth Watching
If you take away just one concept from your AGP report, let it be Time in Range. This is the share of the day your glucose spent inside your target zone, which for most adults is 70 to 180 mg/dL. It is displayed as a stacked, color-coded bar, and it gives you a fuller story than a single A1C number ever could, because it shows the highs and lows that an average can hide.
The bar is usually broken into five bands, and each one matters for a different reason:
- Very Low (below 54 mg/dL): The most urgent band. Time here should be as close to zero as possible.
- Low (54 to 69 mg/dL): Mild lows. A common goal is to keep total time below 70 mg/dL under about 4 percent of the day.
- Target Range (70 to 180 mg/dL): The green zone. A widely used goal for many adults is 70 percent or more, which works out to roughly 17 hours a day.
- High (181 to 250 mg/dL): Elevated but not extreme.
- Very High (above 250 mg/dL): The band to reduce over time for better long-term outcomes.
Here is why this matters more than it might first appear. Two people can have an identical average glucose, yet one spends the day in a smooth, steady range while the other bounces between severe lows and sharp highs. The second person feels worse and carries more risk, even though their average looks fine. Time in Range makes that difference visible, which is exactly why so many care teams now treat it as a primary goal alongside A1C. Your personal targets may differ from the general numbers above, especially if you are older, pregnant, or newer to CGM use, so treat these as a starting point to discuss rather than a rule.
GMI and Glucose Variability: Reading Between the Lines
Just below the Time in Range bar you will usually find two more numbers that add important context: your Glucose Management Indicator and your glucose variability.
The GMI is an estimate of your A1C calculated from your average CGM glucose over the reporting period. It is helpful because you get a lab-like number without waiting for bloodwork, and you can watch it respond to changes much faster. One friendly caution worth remembering: your GMI and your lab A1C will not always match exactly, and that is completely expected. They measure glucose in different ways over different windows, so a gap of a few tenths of a point is normal and not a sign that either number is wrong. If the two are far apart, that is simply a good thing to mention to your care team rather than something to worry about on your own.
Glucose variability, shown as a percentage called the coefficient of variation, describes how much your glucose swings around its average. Lower is generally steadier. Experts often point to 36 percent as a threshold, with values at or below that considered stable and higher values suggesting more ups and downs. High variability often points to things like large post-meal spikes or overnight lows, and it can be a clue about where to focus. It is completely normal for this number to take time to improve, and small, consistent adjustments tend to move it more reliably than dramatic overhauls.
The AGP Graph: Finding Your Daily Story
The centerpiece of the report is the AGP graph itself, and it is genuinely clever once it clicks. Instead of showing 14 separate days, it stacks every day on top of one another onto a single 24-hour timeline, then draws shaded bands to show how your glucose typically behaves at each hour.
The bold line in the middle is your median, meaning half your readings at that time of day fell above it and half below. The shaded areas around it show your spread: a wider band means your glucose was less predictable at that hour, while a narrow band means you were fairly consistent. When you read the graph, you are looking for shape and story rather than individual points:
- Where does the median line drift below target? A dip in the early morning hours, for example, can point to overnight lows worth discussing.
- Where does it climb steeply? A sharp rise after a typical mealtime can reveal that certain meals need more attention.
- Where do the bands get wide? A fat band around dinnertime suggests your evenings are unpredictable, which is useful to know before changing anything.
The daily profiles at the bottom of the report complement this beautifully. If the AGP graph tells you that mornings tend to run high, the daily grid lets you scroll back and see whether that was every morning or just a few. That distinction changes what you and your care team might do about it.
Why It Matters
Learning to read your AGP report turns your CGM from a device that simply beeps at you into a tool that actually teaches you about your own body. When you can point to a specific pattern, like a recurring 3 a.m. dip or a Tuesday-night spike, your appointments become far more productive, and any changes to your routine or therapy can be targeted rather than guesswork. That kind of clarity tends to reduce the daily mental load of diabetes, and it gives caregivers real confidence that things are on track.
At AdaptHealth Diabetes, making diabetes management simpler and more accessible is at the heart of what we do, and that includes helping you get real value from the technology you already wear every day. Whether you use a FreeStyle Libre 3 series reader or a Dexcom G7 receiver, the AGP report is generated the same standardized way, so the skills you build reading one carry over to the other. You can find more plain-language guides like this one in our education center, and our resources page can help you keep the right sensors and supplies on hand so your reports stay complete and uninterrupted.
Frequently Asked Questions About AGP Reports
How many days of CGM data do I need for the AGP report to be accurate?
Experts generally recommend at least 14 days of data, with the sensor actively collecting readings for at least 70 percent of that time. That much data smooths out one-off days, like a birthday party or a sick day, so the patterns you see reflect your typical routine rather than a single unusual event. If your report covers only a few days, it is still worth a look, but hold off on making big changes until you have a fuller picture.
Why is my GMI different from my lab A1C?
This is one of the most common questions, and a small difference is completely normal. Your GMI is estimated from your average CGM glucose over the past couple of weeks, while a lab A1C reflects roughly the past three months and measures glucose in a different way. Factors like your recent glucose trends and individual biology can nudge the two apart. If they differ by more than a little, simply bring it up with your care team, since it can occasionally offer a useful clue rather than a cause for concern.
What is a good Time in Range to aim for?
A widely used general goal for many adults is spending at least 70 percent of the day between 70 and 180 mg/dL, while keeping time below 70 mg/dL under about 4 percent. That said, targets are personal. Older adults, people who are pregnant, and those newer to CGM use often have different goals set with their care team. Think of the standard numbers as a helpful reference point for a conversation, not a one-size-fits-all rule.
What should I do if my AGP graph shows a pattern I do not like?
First, resist the urge to overhaul everything at once. A single pattern, like an afternoon high, is information rather than a verdict. Note when it happens and how consistent it is, then bring the report to your care team, who can help you decide whether it points to meals, timing, activity, or medication. Steady, small adjustments guided by your provider almost always work better than dramatic changes made on your own.
Can I read my AGP report on my own, or do I need my doctor?
You can absolutely learn to read it yourself, and doing so is genuinely empowering. Understanding your Time in Range, GMI, and daily pattern helps you catch trends early and ask better questions. What you should not do on your own is make significant changes to insulin doses or medication based on the report. Use your reading skills to spot patterns and describe them clearly, then let your care team help you translate those observations into any changes to your plan.
Make the Most of Every Reading
Your AGP report is only as good as the data behind it, which means keeping your CGM running consistently with fresh sensors and a reliable way to view your numbers. AdaptHealth Diabetes can help you get the CGM sensors and readers you need, often covered by insurance, so you never have gaps in the data that make your reports harder to trust. Explore our Abbott and Dexcom CGM options or reach out through our contact page to ask about coverage and getting set up.
For more on the concepts behind your report, the American Diabetes Association offers excellent patient-friendly explanations of Time in Range and CGM data at diabetes.org.
Medical Disclaimer: This article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician, diabetes care team, or other qualified health provider before making any changes to your diabetes management plan, including any decisions based on your CGM or AGP report. Never disregard professional medical advice or delay seeking it because of something you have read here.
Sources
- American Diabetes Association (ADA), Standards of Care in Diabetes and Time in Range guidance: https://diabetes.org
- Centers for Disease Control and Prevention (CDC), Managing Diabetes and Monitoring Blood Sugar: https://www.cdc.gov/diabetes
- Association of Diabetes Care & Education Specialists (ADCES), CGM and data interpretation resources: https://www.diabeteseducator.org
- National Institutes of Health / PubMed Central, International Consensus on Time in Range and the standardized AGP report: https://pmc.ncbi.nlm.nih.gov/
