Maryland has long-standing, pre-NSA protections built around two pillars:

1. A statewide all-payer hospital rate system, overseen by the Health Services Cost Review Commission (HSCRC), in place since the 1970s and formalized under the Maryland All-Payer Model Agreement with CMS in 2014. This model requires (with limited exceptions) that all payers pay the same regulated rate for hospital services. 
2. Maryland-specific balance billing protections for HMO and PPO/EPO enrollees, which bar certain out-of-network hospital-based or on-call physicians and ground ambulance providers from balance billing when they accept assignment of benefits. 

The federal No Surprises Act (NSA) then took effect for plan years beginning on or after January 1, 2022, layering federal protections and the federal IDR system on top of these state structures. 

Maryland’s regime is not a classic “surprise billing statute” like Maine or Arizona. Instead, it uses:

• Under the Maryland All-Payer Model Agreement and state law, HSCRC sets uniform hospital rates that must be paid by Medicare, Medicaid, and commercial insurers alike, regardless of network status. 
• Practically, this means that for regulated hospital services, there is already a state-set payment standard; plans do not negotiate separate “OON” facility rates the way they do in other states.
• Patient cost-sharing is still at in-network levels when surprise billing protections apply; the hospital cannot balance bill beyond the regulated charge and allowed cost share.

For commercial plans governed by Maryland law: 

• HMO enrollees
  
  • May not be balance billed for covered services, including ground ambulance services.
  • When they receive emergency care or are treated by an OON provider at an in-network hospital or ambulatory surgical center, they are protected from surprise bills.
• PPO/EPO enrollees
  
  • Hospital-based or on-call physicians who accept assignment of benefits and are paid directly by the PPO/EPO may not balance bill for covered services and cannot ask patients to waive these protections.

So, for many hospital facility charges and hospital-based professional services under Maryland-regulated HMOs/PPOs/EPOs, the combination of all-payer rate setting + state balance-billing rules effectively keeps patients out of the middle and locks in a payment standard.

Maryland is a bifurcated state that uses both its All-Payer Model Agreement (APMA) and the Federal NSA IDR process, depending on the scenario.

Per the official CMS bifurcated-state IDR chart: 

• Federal IDR applies in Maryland to:
  
  • Emergency and non-emergency items and services furnished by OON providers at in-network facilities who are not hospital-based or on call with assignment of benefits to Maryland-regulated EPO/PPO plans.
  • All OON air ambulance services.
• Maryland’s APMA determines the OON rate for claims involving:
  
  • Emergency and non-emergency items and services under HMO, PPO, or EPO plans governed by Maryland law, where hospital facility rates are regulated under the All-Payer Model, and
  • Hospital-based or on-call physicians paid directly by a PPO/EPO via assignment of benefits.

Because hospital facility rates and certain hospital-based professional rates are administratively set under APMA, there is no claim-by-claim state arbitration for those segments in the way Maine or Colorado operate.

For NSA-eligible claims where Federal IDR applies in Maryland:

• The standard NSA 30-day open negotiation period applies:
  
  • Begins when the plan issues its initial payment or denial.
  • Parties must attempt to resolve the dispute.
  • If unresolved, either side may initiate Federal IDR. 

For hospital facility services governed by Maryland’s APMA, rates are predetermined by HSCRC, so there is no state surprise-billing IDR clock—the “dispute” is typically about correct application of regulated rates, handled via regulatory/appeal mechanisms rather than baseball-style arbitration.

For those Maryland claims that do go to Federal IDR, arbitrators use the standard federal criteria, including: 

• Qualified Payment Amount (QPA) – central benchmark
• Provider training and experience
• Patient acuity and case complexity
• Market share of the provider and plan
• Prior contracted rates (last 4 years)
• Good-faith contracting behavior

For hospital services under the All-Payer Model, prices are set prospectively based on statutory policy goals:

• Efficiency, access, equity among payers, and hospital solvency as guiding principles. 
• Global budgets and case-mix methodologies are used to control cost growth and maintain uniform rates for all payers.

There is no case-level “arbitration factor test” for those hospital rates; they are embedded in the HSCRC’s regulatory process.

Key components of Maryland’s framework include:

• Health Services Cost Review Commission (HSCRC) enabling legislation and the Maryland All-Payer Model / Total Cost of Care Model with CMS, which grants Maryland authority to set hospital payment rates for all payers. 
• Maryland-specific balance billing protections, summarized in Maryland Insurance Administration and provider notices, which state that:
  
  • HMO enrollees governed by Maryland law may not be balance billed for covered services, including ground ambulance.
  • PPO/EPO enrollees governed by Maryland law may not be balance billed by hospital-based or on-call physicians who accept assignment of benefits and are paid directly by the PPO/EPO. 
• Federal No Surprises Act regulations under 45 CFR 149.510 / 149.520, which apply in Maryland where APMA does not determine the OON rate. 

Per CMS, Maryland is explicitly listed as a bifurcated state with an All-Payer Model Agreement (APMA): 

• Hospital facility services (emergency + non-emergency) for HMO, PPO, EPO plans governed by Maryland law, where HSCRC rates apply.
• Hospital-based or on-call physicians who:
  
  • Accept assignment of benefits and
  • Are paid directly by a Maryland-regulated PPO or EPO.

In these scenarios:

• Out-of-network rates are determined under Maryland’s APMA / rate-setting system.
• Federal IDR is not used to determine the payment amount.

• Emergency and non-emergency services by OON providers at in-network facilities who are not hospital-based/on-call physicians with AOB to a Maryland PPO/EPO.
• All air ambulance services provided by OON carriers. 
• Self-funded ERISA plans (APMA doesn’t set their professional rates; NSA governs payment disputes).

Bottom line:
Maryland is bifurcated: APMA + state balance-billing rules govern many hospital facility and certain hospital-based professional claims, while NSA + Federal IDR govern everything else in the commercial market.