How Network Adequacy Affects Your CMS Star Ratings

The Star Ratings System and Why It Matters

CMS's Star Ratings system for Medicare Advantage plans is one of the most consequential performance measurement frameworks in American healthcare. Plans rated 4 stars or higher receive a Quality Bonus Payment (QBP) of 5% above their benchmark — a significant revenue advantage. Plans rated 5 stars receive additional enrollment flexibilities, including the ability to market outside open enrollment periods. Plans that fall below 3 stars risk enhanced CMS oversight and, in extreme cases, non-renewal of their contract.

The Star Ratings system evaluates plans across 40+ measures in six domains: Part C and D Star Ratings, Member Experience, Process, Intermediate Outcomes, and Patient Safety. Network adequacy does not appear as a named measure in the Star Ratings system — but its influence on ratings is pervasive and frequently underestimated by network ops teams who view adequacy as a compliance function rather than a quality function.

Part C Star Measures Most Directly Affected by Network Quality

Several Part C Star measures have direct causal relationships with network adequacy and access:

• Getting Needed Care (C09): This HEDIS-adjacent measure captures the percentage of members who report always or usually getting the care they need. Plans with access problems — appointment wait times that exceed CMS standards, closed panels in high-demand specialties — score lower on this measure. It directly captures the member experience of a network that is adequate on paper but insufficient in practice.
• Getting Appointments and Care Quickly (C10): Measures the percentage of members who always or usually get appointments for routine care and specialist care as quickly as they need. A network with thin specialty coverage, closed panels, or inadequate behavioral health access scores poorly here. This measure is one of the most direct proxies for network access quality in the entire Star Ratings system.
• Diabetes Care — Blood Sugar Controlled (C28): Preventive care measures like this one require that members can actually get to a primary care provider or endocrinologist. Plans with urban primary care deserts or specialist access barriers score lower on clinical outcome measures because members can't get the care that produces the outcome.
• Colorectal Cancer Screening (C32): Gastroenterology access directly affects this measure. Plans with thin GI networks in suburban or rural counties see lower screening rates — not because their members don't want the care, but because they can't access it within a reasonable time frame.

How Member Complaints About Access Affect Ratings

CMS incorporates member complaints data from multiple sources into Star Ratings calculations, including the Medicare Advantage Complaint Tracking Module (CTM) and the CAHPS survey. Complaints related to access to care — "my doctor isn't in-network," "I can't get an appointment with a specialist," "my referral was denied" — are among the most damaging to Star Ratings for two reasons.

First, they directly affect measure scores in the Member Experience domain, which carries significant weight in the overall Star calculation. Second, high complaint volumes in access-related categories trigger CMS audit attention that can lead to enhanced oversight across all compliance domains — including adequacy review, provider directory accuracy, and prior authorization processes.

The correlation between adequacy deficiencies and member access complaints is tight and well-documented in CMS audit data. Plans that file exception filings in multiple specialty categories in urban or suburban counties consistently generate higher access complaint rates than plans that file clean adequacy submissions.

Provider Directory Accuracy and Star Ratings

CMS has elevated provider directory accuracy to a significant compliance priority in recent years, and directory accuracy has a direct Star Ratings connection. The Member Experience measure "Rating of Health Plan" is partially driven by member frustration with inaccurate directories — specifically, members who call a provider listed as in-network and discover they are not taking new patients, not taking the plan, or have moved.

CMS conducts secret shopper audits of plan provider directories. Plans with high error rates in secret shopper results receive deficiency findings that contribute to lower Stars. Directory accuracy audit failures are also leading indicators of broader data management problems that affect adequacy filing accuracy.

A directory accuracy program requires quarterly provider outreach to confirm: still at the listed address, still accepting new patients, still accepting the plan, still accepting the specific LOB (MA vs. Medicaid). This is time-consuming work that is typically under-resourced — but the Star Ratings payoff for a plan that moves from 3.5 to 4.0 stars through improved access measures is worth millions in Quality Bonus Payments.

What a Well-Built Network Contributes to 4+ Star Performance

The plans that consistently perform at 4 stars or above share a network quality profile that goes beyond adequacy compliance: they have open-panel providers with reasonable appointment wait times, behavioral health parity that actually works in practice (not just on paper), and provider directories that are accurate within 30 days of any given audit. These characteristics are the product of network strategies that go beyond filing-driven adequacy and invest in ongoing monitoring, directory maintenance, and access quality measurement.

The business case for this investment is clear: a 200,000-member plan that achieves 4-star status earns approximately $200 per member per year in Quality Bonus Payments — $40 million annually. The cost of a robust network monitoring and directory accuracy program is a fraction of that. Network adequacy, properly understood, is not just a regulatory compliance function. It is one of the highest-leverage strategic investments a Medicare Advantage plan can make.