THE SHORT ANSWER: On March 13, 2026, the American College of Cardiology and American Heart Association published an updated dyslipidemia guideline with two real changes most people haven't heard about. First, it recommends every adult get lipoprotein(a), or Lp(a), tested at least once in their life, a Class I recommendation, the strongest level the guideline gives. Lp(a) is more than 90% genetically determined, doesn't change much with diet or exercise, and almost nobody has ever had it checked. Second, the guideline recommends apolipoprotein B, or ApoB, testing for specific higher-risk groups, people with diabetes, high triglycerides, cardiometabolic syndrome, or known cardiovascular disease, especially once their LDL already looks fine. ApoB counts the actual number of artery-clogging particles instead of estimating cholesterol content. Neither test replaces a standard lipid panel. Both catch risk a normal-looking LDL can miss entirely.
What actually changed in March 2026
Cardiology guidelines don't update often, and when they do, the changes tend to matter. The 2026 ACC/AHA dyslipidemia guideline, published jointly with eight other medical societies, made Lp(a) testing a Class I recommendation for the first time in a U.S. guideline, meaning it should happen for essentially every adult, at least once, according to writing committee member Ann Marie Navar, MD, PhD. That's a meaningful shift from "test it if you're curious" to "this is now standard of care."
The guideline sets a threshold of roughly 125 nmol/L, about 50 mg/dL, above which cardiovascular risk increases substantially. Below that number, Lp(a) mostly stays out of the conversation. Above it, it becomes a piece of information your provider should factor into how aggressively other risk factors get managed.
Why test something that's mostly genetic anyway
This is the part people find confusing, and it's actually the point. Lp(a) concentration is determined by your apolipoprotein(a) gene, which accounts for more than 90% of the variation in how much Lp(a) shows up in your blood. Diet, exercise, and most medications barely move it. So why test it at all?
Because knowing the number changes what you do about everything else. Someone with an elevated Lp(a) and borderline LDL is a different clinical picture than someone with the same LDL and a normal Lp(a), even though a standard lipid panel would report them identically. Since Lp(a) doesn't meaningfully change over your lifetime, the guideline treats it as a once-and-done test, not something to recheck annually. You test it once, you factor it into your risk picture permanently, and you move on.
Where ApoB fits, and where it doesn't
ApoB testing gets more attention online than the new guideline actually gives it. The recommendation is specific, not universal. The guideline states that measuring ApoB "may be used to assess any residual ASCVD risk and guide treatment among people with cardiovascular-kidney-metabolic syndrome, Type 2 diabetes, high triglycerides or known cardiovascular disease who have reached their LDL-C and non-HDL-C goals," because ApoB "may be a more accurate risk marker than LDL-C in these groups of people."
The mechanical reason is straightforward. LDL-C estimates how much cholesterol is riding around in your artery-clogging particles. ApoB counts the particles directly, one ApoB molecule per particle. In most people those two numbers track closely enough that LDL is a fine proxy. But in people with diabetes, high triglycerides, or very low LDL to begin with, the particles can carry less cholesterol per particle than average, which makes LDL-C look better than the actual particle count really is. ApoB doesn't have that blind spot, and it's measured directly rather than calculated, so it isn't thrown off by recent food intake the way a triglyceride-dependent LDL calculation can be.
That's a meaningfully different message than "everyone needs ApoB instead of LDL." Most people with straightforward risk profiles are still well served by a standard panel. The people this guideline is actually pointing at are the ones whose LDL already looks controlled but whose other risk factors suggest there might be more going on underneath a number that looks fine on paper.
The pattern behind both changes
Both changes point at the same underlying problem. A single number, run once, interpreted against a generic reference range, can miss real risk in people who look fine on paper. That's the same reason a genetic MTHFR variant matters less than an actual homocysteine level, why serum magnesium is a poor stand-in for total body magnesium, and why an optimal lab range can tell you more than a "normal" one. Cholesterol testing just caught up to that pattern this year, for two specific markers, in two specific ways.
What this means if you've never had these tested
If you've had a lipid panel before, you've almost certainly had total cholesterol, LDL, HDL, and triglycerides measured. Very few people, even people who get annual physicals, have ever had Lp(a) checked, because until this year no major U.S. guideline told providers to order it routinely. If your family has a history of early heart disease that didn't seem to track with anyone's cholesterol numbers, an untested Lp(a) is a common reason why.
ApoB is less urgent to chase down unless you fall into one of the specific groups above: diabetes, high triglycerides, cardiometabolic syndrome, or existing cardiovascular disease with LDL that already looks controlled. Outside those groups, a standard panel plus a one-time Lp(a) covers the guideline's actual recommendation.
How we approach this at Vitality Dartmouth
We build lab panels around what the current evidence actually supports, not around what's trending. As this guideline update shows, that list changes, and staying current means re-reading the primary source instead of repeating last year's protocol.
We treat a one-time Lp(a) as a standard part of a baseline workup through our genomic and lab testing process, since it's inexpensive, doesn't need repeating, and adds real information a standard panel can't provide.
We reserve ApoB for the people the guideline actually points to, rather than running it on everyone as an upsell. If you have diabetes, high triglycerides, or known cardiovascular disease and your LDL already looks fine, that's a specific, evidence-based reason to ask about it.
We connect lab findings to your actual program. If elevated Lp(a) changes how aggressively your other cardiovascular risk factors, weight, blood pressure, inflammation, should be managed, that shapes your plan, not just a line item on a report.
Frequently asked questions
Do I need to get Lp(a) tested every year?
No. Because it's genetically determined and stays stable over your lifetime, the current recommendation treats it as a one-time test. Once you know your number, it typically doesn't need to be repeated.
My LDL is normal. Do I still need ApoB?
Only if you fall into one of the groups the guideline specifically names, diabetes, high triglycerides, cardiometabolic syndrome, or existing cardiovascular disease. Outside those groups, the guideline doesn’t call for it.
Can I lower my Lp(a) with diet or supplements?
Lifestyle changes have shown only modest effects on Lp(a) in the research to date. This is a case where the number itself matters less on its own than how it changes the management of everything else, blood pressure, LDL, inflammation, that is more modifiable.
Do you test for this near me?
Yes. Vitality Dartmouth is based in Dartmouth, MA, and works with clients across the SouthCoast, including New Bedford, Westport, Fairhaven, and Fall River, with RN-supervised lab testing built around current guidelines rather than outdated defaults.
A guideline update like this one is easy to miss if nobody's specifically watching for it. Most people will go years without knowing their Lp(a) number, not because it isn't useful, but because nobody happened to order it before this year. The tests that actually move the needle on your risk are rarely the newest thing in wellness. In this case, one of them is over 20 years old and is finally getting ordered.
This article is for educational purposes only and is not medical advice. Guideline recommendations are general and may not apply to your specific situation. Discuss your individual cardiovascular risk factors and any testing decisions with a licensed healthcare provider.