AutoSoft XC vs. AutoSoft 90 vs. TruSteel: Tandem Infusion Sets

If you use a Tandem pump, you have more infusion set options than most people realize, and the one you were started on at pump training was probably chosen for convenience rather than because someone assessed your body and your routine. That is worth revisiting, because the set is the part of the system that most directly affects whether your sites work.

Here is a straight comparison of the Tandem infusion set options, who each one suits, and how to tell when it is time to switch.

Quick Guide: Which Tandem Set Fits Which Situation

If you want the short version before the detail, this covers most people:

• AutoSoft XC: the general-purpose default. Soft cannula, straight insertion, automatic inserter, longer tubing options.
• AutoSoft 90: similar concept in a lower-profile package, with a shorter cannula option that suits leaner users and children.
• VariSoft: the angled option, for anyone with less subcutaneous fat or who has trouble with straight insertions.
• TruSteel: the steel option, for anyone with repeated kinked cannulas or a sensitivity to plastic cannulas.

All current Tandem sets use the t:lock connector, which means they work across Tandem pumps rather than being locked to one model. That makes switching between them a prescription change rather than a hardware problem.

The Tandem Infusion Set Lineup Compared

Tubing length is a separate choice from set type, and it matters more than people expect. Shorter tubing keeps things tidy if you wear your pump close to your site, and it is the usual pick for the Tandem Mobi, which is designed to be worn on-body. Longer tubing gives you flexibility if you clip your t:slim X2 to a waistband and use sites on your arm or back.

AutoSoft XC vs. AutoSoft 90: The Practical Difference

These two get confused constantly, and the honest answer is that they are close cousins rather than genuinely different approaches. Both use a soft Teflon cannula, both insert straight in at 90 degrees, and both use an automatic inserter that places the cannula with a single press.

The differences come down to feel and profile. The AutoSoft XC has a somewhat larger adhesive footprint, which many people find holds better through exercise and sweat. The AutoSoft 90 sits lower against the skin, which some people prefer under fitted clothing and find catches less on doorways and seat belts.

If you are choosing between them without a specific reason, the practical advice is to try the AutoSoft XC first, since the larger adhesive area tends to be more forgiving. If adhesion is fine but the set feels bulky or catches on things, the AutoSoft 90 is the natural next try. Neither is clinically superior, and this is genuinely a comfort decision you get to make.

When to Move to VariSoft or TruSteel

These two exist to solve specific problems, and if you are having one of those problems, they are worth asking about directly.

VariSoft (angled) is the answer when a straight cannula is going too deep. A 6mm straight cannula in someone with little subcutaneous fat can reach muscle, where insulin absorbs unpredictably and insertion often stings. Because an angled set travels a shallower path, a 13mm angled cannula sits at roughly comparable depth to a much shorter straight one while spanning more tissue. It also lets you see the cannula through a window in some designs, which is useful for confirming placement. The trade-off is manual insertion, which takes a little more technique.

TruSteel is the answer when the cannula keeps failing. It uses a 29-gauge stainless steel needle that stays in place for the wear period, and steel cannot kink. ADCES describes it as a good choice for people who react to plastic cannulas and those with a history of bent cannulas, and it includes an additional adhesive pad for extra security against dislodging. The trade-offs are a shorter recommended wear time, generally two days rather than three, and that some people are more aware of it during movement.

Why this matters: if you have been living with unexplained highs and assuming your pump settings are wrong, a mechanical cause is worth ruling out first. Adjusting basal rates to compensate for a set that intermittently fails creates a moving target nobody can hit. It is completely normal to need two or three tries before landing on your set, and switching is one of the easiest changes in diabetes technology.

Why It Matters

Infusion set failure remains one of the most common causes of unexplained hyperglycemia in pump users, and interrupted insulin delivery is a recognized pathway toward ketones and diabetic ketoacidosis. Research has also highlighted that mechanical stress on the cannula, from tugs on the tubing or the pump dropping, drives a meaningful share of failures. Set choice and tubing management are safety topics as much as comfort topics.

The everyday payoff is different but just as real. When your sites are dependable, you stop treating every high as a mystery, you stop doing 11pm emergency site changes, and your automated insulin delivery system gets clean data to work with.

At AdaptHealth Diabetes, our mission is to make diabetes management simpler and more accessible, and stocking the full range of Tandem sets is part of that. Whichever set you land on, we can keep it coming on schedule alongside your t:slim X2 cartridges or Tandem Mobi cartridges. Browse everything in our Tandem Diabetes collection.

Frequently Asked Questions About Tandem Infusion Sets

Do all Tandem infusion sets work with both the t:slim X2 and the Mobi?

Current Tandem sets use the t:lock connector and are designed to work across Tandem pumps, and Tandem states that the Mobi is compatible with all its infusion sets. Tubing length is the practical consideration, since the Mobi is often worn on-body with very short tubing while the t:slim X2 is usually clipped to clothing. Confirm the specific set and tubing length with your prescriber and with Tandem before ordering, since product lines do change.

How do I know if my cannula is kinking?

Look at the cannula every time you remove a set. A healthy Teflon cannula comes out straight. A bent, crimped, or curled one tells you exactly what went wrong. If you see that more than occasionally, or if you get unexplained highs that resolve immediately after a site change, that pattern points toward kinking. The usual fixes are switching to TruSteel, trying an angled set, or anchoring the tubing so movement does not transfer to the cannula.

Can I use TruSteel for three days like my Teflon set?

No. Steel sets are generally recommended for shorter wear, typically two days rather than three, because the metal needle sitting in tissue is more likely to cause irritation over time. Stretching a steel set past its recommended wear increases the risk of site inflammation and poor absorption. Follow the instructions for your specific set and your care team's guidance rather than applying your old Teflon schedule.

Which set should I use during pregnancy?

This is a conversation for your care team rather than a general rule, but it is common for people to move toward steel sets or angled sets during pregnancy, primarily because delivery reliability matters more than usual and body composition changes over the course of a pregnancy. Site placement also shifts as pregnancy progresses. Raise it early with your obstetric and diabetes teams so you have time to adjust before it becomes urgent.

Will my insurance cover a different set if I switch?

Usually yes, though the covered monthly quantity may change. Because steel sets are changed more often than Teflon ones, the allowed quantity differs, and some plans have preferred products within the category. A prescription update is required either way since sets are ordered by specific product. Our team can verify what your plan allows before your prescriber writes the new order so nothing gets rejected.

Try a Different Set Without the Hassle

If your current set is not working, that is worth fixing, and it does not have to be complicated. AdaptHealth Diabetes stocks the full Tandem infusion set lineup, and we can confirm compatibility with your pump, check what your plan covers, and coordinate the prescription change with your prescriber. Reach out through our contact page, or visit our resources page for help with ordering and coverage.

For general guidance on high glucose, ketones, and when to seek care, the CDC provides patient information at cdc.gov/diabetes.

Medical Disclaimer: This article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Product lines, specifications, and compatibility change over time, so confirm current details with Tandem Diabetes Care and your prescriber. Cannula type and length should be selected with your diabetes care team. If you have high glucose with ketones or cannot restore insulin delivery, seek medical care promptly.

Sources

• Association of Diabetes Care & Education Specialists (ADCES), danatech TruSteel Infusion Set profile: https://www.adces.org/education/danatech/insulin-pumps/infusion-sets/product-detail/trusteel-infusion-set
• Association of Diabetes Care & Education Specialists (ADCES), danatech Find and Compare Infusion Sets: https://www.adces.org/education/danatech/insulin-pumps/infusion-sets
• Optimizing Duration of Usage of Insulin Infusion Sets, Journal of Diabetes Science and Technology (NIH/PMC): https://pmc.ncbi.nlm.nih.gov/articles/PMC11571491/
• Randomized Trial of Infusion Set Function: Steel Versus Teflon, Journal of Diabetes Science and Technology (NIH/PMC): https://pmc.ncbi.nlm.nih.gov/articles/PMC3887416/
• Centers for Disease Control and Prevention (CDC), Diabetic Ketoacidosis: https://www.cdc.gov/diabetes/about/diabetic-ketoacidosis.html