Call any three in-network specialists listed in a health plan directory, and statistically, there's a reasonable chance at least one of them won't pan out. Wrong number, no longer accepting that insurance, not taking new patients — or simply a provider who moved practices two years ago and never got updated in the system.
This isn't an edge case problem. A 2023 study published in JAMA that analyzed provider directories across five national health plans found that 81% of physician listings contained inconsistencies or inaccuracies — wrong addresses, mismatched specialties, or providers who were unreachable entirely. A 2025 analysis found that only two payers out of 124 surveyed had reached even 70% directory accuracy. And a 2024 AJMC secret shopper study that re-audited previously flagged listings found only 13% of inaccurate provider records had been fully corrected after an average of 540 days.
That's the foundation of the network adequacy problem: plans are being measured against data they don't fully control and can't always verify. Understanding how adequacy is defined, how it's measured, and where measurement consistently breaks down is essential for any payer trying to build a network that works in practice, not just on paper.
What Is Healthcare Network Adequacy and Why Does It Matter for Health Plans?
Network adequacy, at its most basic, means members can access the care their plan covers. Close enough to reach, soon enough to matter, with providers who are actually available. Regulatory bodies, including CMS, state insurance commissioners, and accreditation organizations like NCQA have built formal frameworks around this concept — translating it into measurable thresholds that plans must demonstrate they meet.
Those thresholds typically address four things: whether enough providers are contracted per enrollee, whether those providers are geographically reachable, whether appointments are available within a reasonable timeframe, and whether the information in the directory actually reflects who's accessible. The challenge is that all four dimensions can quietly deteriorate between review cycles and often do.
A plan might clear every quantitative threshold in its filing and still leave members unable to access care. That gap — between regulatory compliance and genuine access — is what network adequacy analysis is ultimately trying to close.
Why Provider Directory Accuracy Is the Foundation of Any Network Adequacy Analysis
Every adequacy measurement starts with provider data. And provider data has a well-documented accuracy problem.
Physicians change practice locations, take on new group affiliations, or reduce their patient panels without any of that information flowing reliably to payers. Health systems merge or restructure. Solo practitioners retire. Contracted providers go months without seeing a single patient from a given plan — sometimes because they've quietly stopped accepting it. The 2025 analysis found that 35% of payers remained stuck between 45% and 55% directory accuracy despite years of CMS scrutiny, with only two payers out of 124 clearing the 70% mark.
The industry spends billions of dollars annually on provider data management and still hasn't closed this gap at scale. Part of the reason is structural: most provider data flows from providers to plans through a combination of self-reported attestation, credentialing submissions, and group-level roster feeds — none of which were designed for the kind of real-time accuracy that meaningful network adequacy analysis depends on.
The result is what's often called a "ghost network" — a directory full of providers who exist on paper but can't be accessed in practice. When adequacy filings are built on ghost network data, the results look clean. Members bear the consequences when they try to find actual care.
How Payers Conduct Network Adequacy Analysis: Time-and-Distance, Wait Times, and Specialty Gaps
1. Time-and-Distance Standards
The most widely used regulatory method ties adequacy to geography. CMS and state regulators publish maximum drive time and mileage thresholds between members and in-network providers, broken down by specialty and county type. Under current federal regulations, MA plans must ensure that at least 90% of enrollees in a county can reach an in-network provider within CMS's published time and distance maximums — thresholds that vary by county designation and specialty type, from 10 minutes/5 miles in large urban areas to significantly wider allowances in rural and extreme-access counties.
Running network adequacy analysis against these standards means geocoding enrolled populations and contracted provider locations, then checking, by specialty, whether the required thresholds are met for each member. Math isn't complicated. What complicates it is the reliability of the provider's location data being geocoded — which brings the discussion back to the same data quality problem.
2. Appointment Availability
Time-and-distance answers whether a provider is geographically close. It doesn't answer whether a member can actually get seen. Regulators have moved to address this through appointment wait time standards — CMS's Medicaid managed care rules, finalized in 2024, require states to enforce maximum wait times of 10 business days for routine outpatient behavioral health appointments and 15 business days for routine primary care and OB/GYN.
Measuring appointment access requires provider network monitoring that goes well beyond reviewing directory data. The standard approach is secret shoppers calling — staff or vendors contacting in-network providers as if they were patients to verify availability. It's resource-intensive and difficult to run at meaningful scale, but it remains the most direct way to verify that listed providers can actually deliver timely care.
3. Specialty Ratios and Harder-to-See Gaps
Adequacy standards for some lines of business also specify minimum provider-to-enrollee ratios by specialty. This is where aggregate compliance metrics begin to mask real problems. A plan can post strong overall numbers while being critically thin in specific specialties — and that thinness may never surface in a summary report.
Behavioral health is the clearest example. 43 out of 44 states reported a behavioral health workforce shortage in a 2024 NRI survey. A 2025 HHS OIG report found that 15 Medicare Advantage plans had networks covering less than 10% of the available behavioral health workforce in their counties — and seven had no in-network behavioral health providers at all. These plans were not necessarily failing their aggregate adequacy filings. They were failing their members.
This kind of gap is only visible when network adequacy analysis is conducted at the specialty level, mapped against actual member distribution, rather than reviewed in aggregate across the full network.
CMS, Medicaid, and ACA Network Adequacy Requirements: What Payers Need to Know in 2026
Network adequacy requirements vary by line of business and have been evolving quickly.
Medicare Advantage plans are subject to CMS's time-and-distance standards, specialty-specific provider ratios, and increasingly rigorous behavioral health requirements. The CY 2025 final rule added Outpatient Behavioral Health as a formal facility-specialty category subject to network adequacy evaluation — covering a range of provider types from mental health counselors to addiction medicine physicians, with time-and-distance requirements ranging from 20 minutes/10 miles in large metro areas to 110 minutes/100 miles in counties with extreme access limitations. CMS also requires MA organizations to conduct ongoing provider network monitoring throughout the contract year, not just at application time.
Medicaid managed care standards are set by states but require CMS approval and have been subject to increasing federal attention. The 2024 Medicaid managed care final rule introduced formal appointment wait time standards for the first time at the federal level and strengthened requirements for provider network monitoring, including mandatory secret shopper surveys and enrollee experience data.
Commercial and ACA marketplace plans face a patchwork of standards. A 2025 final rule established that starting January 1, 2026, state-based marketplace plans must implement quantitative time-and-distance standards comparable to the federal exchange — a significant tightening for states that had previously operated under weaker requirements.
NCQA and URAC accreditation add a parallel compliance layer that most plans selling to large employers can't ignore.
Common Provider Network Monitoring Failures That Put Health Plans at Regulatory Risk
Most adequacy failures aren't the result of bad intentions. They're the result of systems and processes that weren't built to keep pace with how fast provider networks change.
Attestation-based provider network monitoring is the most common structural weakness. Sending providers an annual form asking them to confirm their directory information is current doesn't produce accurate data — it produces attestations. Providers confirm, plans file, and the gap between what the directory says and what members' experience never actually closes.
Siloed systems compound the problem. Provider information typically lives in credentialing, contracting, and directory systems that operate independently and often disagree with each other. A physician might be credentialed at one address, contracted at another, and listed in the member directory at a third. The member sees the directory. When that information is wrong, the member absorbs the cost of the error — time spent calling disconnected numbers, driving to locations where no one recognizes the provider's name.
Geography creates additional complexity that aggregate reporting tends to flatten. A county-level analysis might show adequate specialist coverage while specific zip codes within that county have no in-network providers within a reasonable drive. Rural markets face genuine supply constraints that no network development strategy fully resolves. Urban markets have their own version — high overall provider density masking serious gaps in particular neighborhoods or for particular languages.
These are all solvable problems, at least partially. But solving them requires treating adequacy as an operational function that runs continuously, not a compliance exercise that runs once a year.
Best Practices for Building a Continuous Provider Network Monitoring Program
Plans that maintain genuinely adequate networks tend to share a few operational characteristics.
They validate provider data continuously, using a combination of automated outreach, claims-based activity signals, and third-party data sources rather than relying on provider self-reporting alone. When a contracted provider has generated no claims activity in 12 months, that's a signal worth investigating before a member tries to schedule with them. Provider data accuracy gets treated as a data quality problem requiring ongoing investment — not a credentialing formality that gets done once.
They approach network adequacy analysis as an ongoing workflow rather than a filing exercise. This means regular reviews at the specialty and geography level, exception reporting that surfaces gaps before they become regulatory findings, and network development teams with visibility into where the next gap is likely to emerge — not just where the last one was found.
They also use scenario modeling before network changes happen. When a large physician group exits the network or a major health system consolidates, the adequacy impact can be significant and fast-moving. Plans that model the adequacy implications of network changes in advance can respond. Plans that discover the gap during a compliance review are already behind.
The Real Cost of Network Adequacy Failures: Patient Access, Plan Performance, and Legal Exposure
The regulatory frameworks exist because regulators needed to create consequences for plans that weren't maintaining genuine access. But it's worth keeping the member experience in frame.
When a woman newly diagnosed with cancer can't reach an in-network oncologist because the three listed in her area are inactive, incorrect, or not accepting her plan — she doesn't experience a compliance gap. She experiences a delay in cancer treatment. When a parent spends weeks trying to find a pediatric behavioral health provider, the difficulty they're facing reflects a system-wide problem: according to SAMHSA's 2024 National Survey on Drug Use and Health, 61.5 million U.S. adults had a mental illness that year, and nearly half — 48% — did not receive treatment. The national average wait time for behavioral health services has reached 48 days, according to the National Council for Mental Wellbeing's 2025 data. The adequacy standard that technically passed is cold comfort, when the wait stretches two months.
Network adequacy analysis and provider network monitoring programs exist, at their best, to prevent those situations — to ensure that what's in the directory reflects what members can access. Plans that build their adequacy programs around that purpose, rather than around the minimum threshold required to pass a review, tend to build better networks. They also tend to face fewer regulatory and legal surprises, as courts and enforcement agencies have become increasingly willing to scrutinize the gap between paper adequacy and actual access.
Key Takeaways: Network Adequacy Analysis and Provider Network Monitoring in Practice
Provider data quality is the foundation. When the underlying data is unreliable, adequacy filings produce results that look clean on paper while members hit dead ends in the real world. No measurement methodology can compensate for data that hasn't been validated.
Ongoing provider network monitoring — not annual attestation, not periodic audits — is what it actually takes to keep pace with how quickly networks change. The providers in your directory today are not the same set of providers who will be accessible to your members six months from now.
Aggregate compliance masks specialty gaps. Behavioral health, maternal care, and oncology are the categories most likely to show serious access problems that a summary adequacy review won't surface. Specialty-level and geography-level analysis is the only way to find them before members do.
Adequacy is ultimately an access problem, not a documentation problem. Plans that build their programs around that distinction produce better outcomes for members — and more durable compliance.
