LEAD (Long-term Enhanced ACO Design) is one of the most ambitious ACO models CMS has ever put into production—a 10-year commitment with a fixed baseline, capitation at the core, and a benchmarking structure that rewards organizations who get the details right from the start. The decisions ACOs are making right now around TIN composition and risk track selection will set them up for long-term success in the model. What follows are the strategic dimensions I think deserve more attention than they're currently getting.
Of course risk appetite is part of this decision. An organization that isn't operationally ready to absorb downside shouldn't be forcing itself into Global. That's a real consideration and it doesn't go away.
But here's what I think is underappreciated: the Global vs. Professional decision doesn't have to be all-or-nothing at the organization level. And it's not just about which track you choose, which TINs you're including or excluding from your ACO in the first place is equally part of the decision. Depending on how your TIN-level benchmarks look and whether specific providers push you into higher-spending or lower-spending territory, it may make strategic sense to structure some TINs under a Global risk ACO and others under a Professional ACO.
Higher-spending ACOs in Global get a discount ramp that starts at 1.75%, which is more manageable than the flat 3% lower-spending ACOs face from day one. Lower-spending ACOs, meanwhile, are eligible for the regional efficiency adjustment but face that flat discount immediately. The admin add-on available to higher-spending ACOs adds another layer: a 1.5% applied to the benchmark is meaningful, and which TINs you include is what determines whether you qualify for it.
The point is that this isn't a single binary choice. It's a composition opportunity. And the answer looks different depending on which providers you're putting where, what their historical expenditure profiles look like, and how each combination affects your spending designation.
Risk appetite alone doesn't tell you any of that. What does is scenario generation: the ability to flex your TIN combinations, your cost trend assumptions, your risk score trajectory, and see how the Global vs. Professional math shifts under each one, before having to commit. That's exactly what Arbital ATLAS is built to do. Some ACOs will find Global looks clearly better across every scenario they run. Others will find Professional holds up better than expected. Most will find the answer depends on which assumptions they're willing to commit to, and ATLAS lets you pressure-test all of them before you sign.
ACOs have always invested in Risk Adjustment. That's not new. What's new under LEAD is the timing and certainty of the return.
Under prospective Risk Adjustment, coding work done this year generates a risk score that affects next year's benchmark (assuming the member re-attributes to your ACO). That's two layers of deferral and uncertainty baked into every coding investment you make. You do the work now, you wait a year, and you hope the member is still yours when the benefit materializes.
The High Needs cohort in LEAD removes both of those constraints. Because risk scores are derived from claims in the same performance year, better coding and documentation this year improves your benchmark this year. And because the member is currently attributed to you, there's no attribution risk to hedge against. The payoff is immediate and it's on a population you already own. It's worth noting that concurrent Risk Adjustment isn't entirely new. ACOs that participated in the High Needs track of ACO REACH operated under this same model. What is new however, is that concurrent Risk Adjustment now applies across all LEAD ACOs with High Needs attribution, not just those that specifically opted into a High Needs track. For many ACOs, this will be their first time managing this dynamic.
That also means coding and cost reduction are now additive levers operating in the same performance year - lower total cost of care through care management, and simultaneously improve your risk scores through better documentation. For ACOs with significant High Needs attribution, that's a fundamentally different strategic posture than prospective Risk Adjustment ever required, and it should be reflected in how resources are being allocated now.
LEAD includes a one-time mid-year window to add Participant TIN, available to LEAD ACOs that select Hybrid Alignment. The instinct for most ACOs will be to treat this as a membership growth opportunity: bring in more providers, grow the attributed population, and expand the program.
That instinct isn't wrong, but it's incomplete. Adding TINs mid-year doesn't just change your headcount. It changes your benchmark. It shifts your cohort mix. And while your higher-spending vs. lower-spending designation is locked in before the start of each performance year—meaning mid-year additions won't flip your designation for the current year—the providers you add now become part of your spending profile going into future performance years, which affects your designation and admin add-on eligibility down the road. These aren't abstract risks, they're concrete financial dynamics that play out differently depending on which providers you're adding and what their historical expenditure and attribution profiles look like.
The ACOs that will use the mid-year window well are the ones that model the benchmark impact before they add, not after. The question isn't just "does this provider bring good attribution?" It's "what does adding this provider do to our numbers, and is the net effect worth it?" Arbital ATLAS is built to answer exactly that. Run the scenario, see how your benchmark and cohort mix shift, and make the call with the full picture in front of you rather than discovering the implications after the window has closed.
What connects all three of these (track selection, concurrent Risk Adjustment strategy, mid-year TIN adds) is that they're decisions that look manageable on the surface, but have layered financial implications that only become visible when you model them at the right level of detail.
Arbital ATLAS is a TIN-level scenario generation platform built specifically for LEAD. Through an intuitive, flexible interface, ATLAS gives ACOs a fast, clear view of how their TIN composition affects financial performance—powered by national VRDC data and deep actuarial expertise. Users can select different provider combinations and instantly see what each does to your attributed population, benchmark, cohort mix, and spending designation. You can flex risk score assumptions, adjust cost trend inputs, and compare Global vs. Professional side by side, including scenarios where different TINs sit in different tracks. It's built to make these decisions fast, rigorous, and grounded in your actual data rather than estimates built under deadline pressure.
The organizations that will set themselves up for success in LEAD are the ones building that analytical discipline now, not after the first performance year settlement lands.
Netanel Lederer, ASA, MAAA, MHCDS, is Director of Actuarial Services at Arbital Health. A value-based care actuary and enthusiast, he spends his days working with clients across CMS/CMMI programs, Medicare Advantage risk arrangements, and specialty risk contracts. He spearheads Arbital ATLAS and plays an active role in shaping Arbital's broader Actuarial AI platform.