Cardiology's Post-Payment Scrutiny: What ABA's Audit Wave Already Taught Us

In cardiology, the pattern regulators are watching is pretty simple: where care is being delivered is changing faster than the clinical picture would suggest.

OIG found that overall volume and Part B payments for peripheral vascular procedures actually declined between 2019 and 2023. What changed was where those procedures were happening. More moved into office-based labs, where physician reimbursement is higher. OIG’s concern wasn’t simply that spending was going up. It was that the shift toward office-based labs wasn’t fully explained by changes in the patients being treated or the care they needed.

That’s similar to what happened in ABA, where spending grew faster than the population receiving services. The difference is that cardiology’s version shows up in where and how care is being billed, rather than overall growth: the billing pattern is changing in a way that the clinical record doesn’t fully explain.

There are already a few different oversight efforts focused on this. OIG flagged the vascular procedure patterns, and CMS has agreed to follow up through its program integrity work. RACs have also added selective catheter placement to their active audit targets, including CPT 36247 and CPT 37229, which are often billed alongside the procedures OIG flagged.

Remote patient monitoring is another area to watch. Medicare RPM payments grew from roughly $409 million in 2023 to $536 million in 2024. OIG has flagged the pace of that growth along with billing patterns that could point to improper claims. A dedicated Part B RPM audit announced in late 2024 is expected to report in 2026. For cardiology practices, this is particularly relevant because device and remote monitoring have become a meaningful part of how many practices operate and generate revenue. This isn’t peripheral to the specialty. It touches a core part of the business.

Medicare Advantage adds another layer. In February 2026, OIG released new MA compliance guidance, its first MA-specific update since 1999. The guidance focuses on how diagnosis codes are used to determine risk-adjusted payments, including retrospective chart reviews that add diagnoses without a corresponding change in care, or leave diagnoses on a patient’s record after a review finds they aren’t supported. While the guidance is directed at MA organizations rather than cardiologists, cardiology practices are still part of the documentation and coding process under review. Cardiac conditions can also carry significant weight in risk adjustment, making accurate documentation especially important.

So there are three different areas of oversight moving at once: vascular procedures, RPM, and MA risk adjustment. They’re coming from different places and looking at different parts of the business, but they point to the same broader shift: regulators are paying closer attention to billing patterns that don’t have a clear clinical explanation behind them.

That makes cardiology’s current environment a little different from ABA’s. ABA had one obvious spending curve that eventually pulled a lot of scrutiny into focus. Cardiology has several smaller signals building at the same time, which can be easier to miss until they turn into an audit.

Billing volume that doesn’t track with clinical status can draw attention. In cardiology, OIG flagged this in its review of peripheral vascular procedures. Overall procedure volume declined, but the share performed in office-based labs, where reimbursement is higher, continued to increase without a clear clinical explanation. ABA auditors saw a similar pattern when treatment hours stayed flat even as a child’s progress changed. The specialty is different, but the question is the same: can the record explain why the volume looks the way it does?

Documentation that looks the same from case to case is another easy place to draw scrutiny. Current RAC guidance on vascular procedures calls out medical necessity and catheter selectivity language that reads as generic rather than specific to the patient. An operative or imaging note that could apply to almost anyone is harder to defend than one that clearly reflects what happened in that case. ABA state audits found a similar issue in progress notes that barely changed from one client to another. The terminology is different, but the concern is the same.

Every number on a claim should have something in the record behind it. In cardiology, that can mean device or monitoring data that doesn’t line up with what was billed. In ABA, auditors found issues where staffing ratios appeared on claims without documentation explaining the clinical need. In both cases, the problem is straightforward: something was billed that the chart doesn’t clearly support.

Auditors also want to see that lower-intensity options were considered before moving to intervention. RAC guidance on vascular procedures asks whether conservative treatment was tried and documented before an intervention. When that history is missing or thin, it can become a point of scrutiny even when the eventual procedure was appropriate. ABA reviews raised a similar question around whether less intensive treatment had been attempted before escalating. Sparse caregiver engagement notes could make it harder to show that it had.

The overlap between ABA and cardiology isn’t really about the specialties themselves. These are the kinds of questions that tend to emerge once post-payment review gets more active. ABA’s toolkit brought together patterns that seven states had already identified independently. Cardiology is earlier in that process, with audits and RAC activity picking up before there’s a single document tying it all together. But the questions auditors are asking are already starting to look familiar.

Cardiology practices can make a strong clinical case and still run into trouble if the documentation doesn’t support it. The vascular RAC guidance and upcoming RPM audit both come back to a pretty basic question: can the medical record support what was billed? Auditors are looking for clear documentation of medical necessity, catheter selectivity, and the reasoning behind ongoing monitoring.

That matters because a clinically appropriate procedure can still raise questions if the record doesn’t clearly connect the clinical decision to the claim. The care may have made perfect sense, but if the chart doesn’t show why, it becomes harder to defend.

There’s a useful parallel in ABA. Camber’s claims analysis, done in collaboration with a16z, found that documentation and information gaps were the biggest source of claims rework, ahead of coverage and credentialing issues combined. They accounted for nearly 20% of denied dollars. About 72% of claims were clean on the first submission, while the remaining 28% needed some level of rework.

Cardiology and ABA have very different billing models, but the underlying lesson is relevant. The documentation gaps that create friction in everyday billing can become much more important once auditors start looking for them.

For cardiology practices, that makes documentation a practical place to get ahead of increased scrutiny. Better documentation can reduce avoidable rework today while making claims easier to defend if they’re reviewed later.