Keystone First Billing Guide for Behavioral

• KF
• Medicaid MCO

Keystone First

Keystone First Medicaid MCO provider guide for southeastern PA — credentialing, prior authorization, VOB, and behavioral health billing (AmeriHealth Caritas).

Quick Reference

Payer Type

Medicaid MCO

Parent Company

AmeriHealth Caritas

Headquarters

Philadelphia, PA

Provider Portal

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Portal Guide

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Credentialing

CAQH ProView plus Pennsylvania Medicaid enrollment (PROMISe)

Timeline

60-120 days

Coverage

1 states

Last Verified

Apr 19, 2026

Published

Apr 19, 2026

Reading Time

10 min

Covered Levels of Care

• Medically Managed Detoxification
• Residential Treatment (via PA 1115 SUD waiver)
• Partial Hospitalization (PHP)
• Intensive Outpatient (IOP)
• Outpatient Treatment
• Crisis Stabilization and Mobile Crisis
• Medication-Assisted Treatment (MAT)
• Peer Support and Recovery Services

Medical Necessity Criteria

• Pennsylvania Medicaid Clinical Criteria
• ASAM Criteria (for SUD level of care determinations)
• LOCUS (Level of Care Utilization System) for mental health

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Overview

Keystone First is the Medicaid managed care brand operated by AmeriHealth Caritas in southeastern Pennsylvania, serving members in Philadelphia, Bucks, Chester, Delaware, and Montgomery counties. Keystone First is not a standalone corporation — it is one of several regional operating brands through which AmeriHealth Caritas, one of the largest Medicaid managed care organizations in the United States, delivers Medicaid managed care across its multi-state footprint. AmeriHealth Caritas is itself a joint venture owned by Independence Health Group (the parent of Independence Blue Cross) and Blue Cross Blue Shield of Michigan, giving Keystone First deep ties to the dominant commercial insurance infrastructure in the Philadelphia region.

The southeastern Pennsylvania region that Keystone First serves is one of the most complex behavioral health markets in the country. Philadelphia has consistently ranked among U.S. cities most severely affected by the opioid epidemic, and the five-county region has a large concentration of community-based treatment organizations, hospital-based behavioral health programs, and safety-net providers. Keystone First administers Medicaid managed care for the region under Pennsylvania’s HealthChoices physical health managed care program and, as a licensed Medicaid MCO, is obligated to follow the Pennsylvania Department of Human Services (PA DHS) Medicaid managed care contract terms, which set the floor for covered services, authorization standards, timely filing rules, and provider network requirements.

For behavioral health treatment providers, Keystone First is often the primary Medicaid payer relationship for organizations serving low-income Philadelphia-area communities. Providers should understand that behavioral health benefits for Keystone First members may involve two distinct systems: the physical health MCO contract (managed by Keystone First / AmeriHealth Caritas) and, for members requiring Community Behavioral Health (CBH) services, the managed behavioral health organization (MBHO) that administers the behavioral health carve-out for Philadelphia County. The interplay between Keystone First and CBH — Community Behavioral Health, the City of Philadelphia’s behavioral health MCO — is a critical operational consideration for Philadelphia-based providers.

Behavioral Health Coverage

Keystone First covers behavioral health services consistent with Pennsylvania Medicaid’s HealthChoices program and any applicable federal waiver authorities. Pennsylvania’s behavioral health benefit structure has historically been administered through a managed behavioral health organization (MBHO) carve-out in most counties, though Pennsylvania has been pursuing behavioral health integration as part of its Medicaid managed care reform agenda. The specific structure of behavioral health benefit administration — whether integrated into the Keystone First physical health contract or carved out to a separate MBHO — is governed by the current PA DHS contract terms and the county-specific program design.

In Philadelphia County specifically, Community Behavioral Health (CBH) administers the behavioral health HealthChoices carve-out, meaning that most specialty behavioral health services for Philadelphia Medicaid members are authorized and reimbursed through CBH rather than through Keystone First directly. Providers serving Philadelphia Medicaid members must understand whether a given service falls under the Keystone First medical benefit or the CBH behavioral health carve-out before submitting claims. In Bucks, Chester, Delaware, and Montgomery counties, the behavioral health carve-out structure may differ — confirm the applicable county MBHO arrangement with Keystone First or PA DHS.

Commonly covered behavioral health services across Pennsylvania Medicaid include outpatient individual, group, and family therapy; psychiatric evaluation and medication management; intensive outpatient programs (IOP); partial hospitalization programs (PHP); crisis stabilization and mobile crisis; and medication-assisted treatment for opioid and alcohol use disorders. Pennsylvania’s Section 1115 SUD waiver — one of the most comprehensive in the country — expands residential SUD treatment coverage to qualifying facilities by waiving the IMD exclusion for short-term stays, typically up to 30 days per episode. Residential levels include ASAM 3.1 (clinically managed low-intensity), 3.5 (clinically managed high-intensity), and 3.7 (medically monitored intensive inpatient).

Medical necessity for SUD services follows the ASAM Criteria framework that Pennsylvania has adopted as its standard for residential and intensive outpatient level-of-care determinations. Mental health services are evaluated using LOCUS (Level of Care Utilization System) for adults and CALOCUS for children and adolescents, which Pennsylvania has adopted statewide for Medicaid managed care mental health reviews. Clinical documentation should be structured around the applicable tool for the service type and member age group.

Credentialing and Provider Enrollment

Keystone First uses CAQH ProView as its primary credentialing data source, consistent with all AmeriHealth Caritas plans. Before applying for Keystone First network participation, ensure that all individual clinicians and your facility have fully attested, current CAQH ProView profiles. The profile must reflect active Pennsylvania professional licensure, NPI and taxonomy codes, current malpractice coverage, facility accreditation certificates, and applicable PA DHS or PA DDAP (Department of Drug and Alcohol Programs) facility certifications.

Pennsylvania Medicaid enrollment through PROMISe (Provider Reimbursement and Operations Management Information System) — administered by the Pennsylvania Department of Human Services — is a prerequisite to contracting with Keystone First. Enroll through the PROMISe provider portal before or concurrently with your Keystone First application. PROMISe enrollment requires submission of applicable PA facility licensure, NPI, W-9, and other documentation, and the process can take several weeks. Claims will not pay until PROMISe enrollment is confirmed and active, even if Keystone First credentialing is complete.

For SUD treatment facilities, Pennsylvania DDAP facility licensure (Bureau of Drug and Alcohol Programs licensure) is required in addition to standard PROMISe enrollment. Facilities seeking to provide residential SUD services under Pennsylvania’s 1115 SUD waiver must ensure their DDAP licensure covers the specific ASAM level of care for which they intend to bill. Joint Commission, CARF, or other accreditation recognized by PA DHS may also be required depending on level of care.

After receipt of a complete credentialing application, Keystone First credentialing typically takes 60 to 120 days. Providers in the Philadelphia-area CBH carve-out geography should also contact CBH separately regarding network participation for behavioral health carve-out services — credentialing with Keystone First does not substitute for CBH network participation when CBH is the responsible payer. Recredentialing occurs on a standard three-year cycle.

Verification of Benefits (VOB)

Benefit verification for Keystone First members requires a two-step process. First, confirm active Pennsylvania Medicaid enrollment and MCO assignment through PROMISe — the PA DHS Medicaid eligibility system. Use the PROMISe provider portal, a standard HIPAA 270/271 transaction, or the PA DHS automated eligibility verification line to confirm the member is enrolled in Medicaid and assigned to Keystone First on the date of service. Pennsylvania has multiple HealthChoices MCOs, and member assignments vary by county. If the member is not assigned to Keystone First, claims will be denied regardless of what any other system shows.

Second, verify plan-specific behavioral health benefits and determine the applicable benefit structure through the NaviNet provider portal (navinet.navimedix.com), which is the primary provider portal platform used by all AmeriHealth Caritas plans including Keystone First. NaviNet provides eligibility inquiries, benefits detail, coverage information, authorization lookups, and claim status. For behavioral health services, also determine whether the member’s benefits are managed by Keystone First directly or carved out to the applicable county MBHO. For Philadelphia County members, contact Community Behavioral Health (CBH) for behavioral health benefit verification.

Medi-Cal eligibility can change monthly. Re-verify on or near every date of service. Because Medicaid is the payer of last resort, screen for commercial insurance, Medicare, TRICARE, or VA coverage before billing Keystone First. Document each VOB interaction with date, representative name, reference number, the confirmed benefits, and any applicable authorization requirements.

Prior Authorization Requirements

Keystone First requires prior authorization for residential SUD treatment, medically managed detoxification, inpatient psychiatric hospitalization, and partial hospitalization programs. IOP authorization requirements depend on the county and the applicable behavioral health benefit structure. In Philadelphia County, authorization for many behavioral health services covered under the CBH carve-out is managed by CBH — do not submit these requests to Keystone First.

For services within the Keystone First direct behavioral health benefit, authorization requests are submitted through NaviNet, by fax, or by phone to the Keystone First utilization management team. The preferred submission method is NaviNet for electronic requests. Clinical documentation should cover the member’s diagnoses, presenting symptoms, substance use or psychiatric history, current functional status, prior treatment episodes, and the proposed treatment plan. For SUD services, organize the clinical narrative around the six ASAM Criteria dimensions. For mental health services, document against LOCUS or CALOCUS criteria as appropriate for the member’s age.

Pennsylvania Medicaid places specific expectations on concurrent review documentation for residential and inpatient levels. Concurrent reviews are typically required every 5 to 7 days for residential SUD treatment and inpatient psychiatric care, and every 7 to 14 days for PHP. Each review requires updated documentation of clinical progress, treatment response, continued medical necessity, and active discharge planning. If a continued-stay request is denied, request a peer-to-peer review with the Keystone First medical director before filing a formal Medicaid grievance and appeal.

Claims and Billing

Keystone First accepts electronic claims through standard EDI 837I (institutional, UB-04) and 837P (professional, CMS-1500) formats via clearinghouses, and through NaviNet. Electronic submission is strongly preferred. Confirm the correct Keystone First payer ID with your clearinghouse — Keystone First has a distinct payer ID separate from AmeriHealth Caritas Pennsylvania and other AmeriHealth Caritas subsidiaries. Using the wrong payer ID will result in claim rejections that do not appear as Keystone First denials.

Billing codes, modifiers, and reimbursement rates follow the Pennsylvania Medicaid fee schedule and the Keystone First provider agreement. Pennsylvania uses a mix of CPT codes for mental health services, H-codes for SUD outpatient and IOP/PHP services, and HCPCS codes for MAT medications. Residential SUD services may require specific revenue codes and procedure codes aligned with the applicable ASAM level of care. The Keystone First provider manual, available through providers.keystonefirstpa.com and NaviNet, contains current billing guidance and code references.

Timely filing for Keystone First Medicaid claims follows Pennsylvania Medicaid managed care contract requirements. Pennsylvania MCO contracts commonly specify initial claim submission within 95 days of the date of service, though your Keystone First provider agreement may differ. Corrected claims and COB adjustments have their own timely filing windows. Late claims have very limited recourse under Pennsylvania Medicaid rules — build timely filing tracking into your billing system from the start.

Common denial reasons include claims submitted to Keystone First for services covered under the CBH behavioral health carve-out, member not enrolled in PA Medicaid or assigned to a different MCO, missing prior authorization, incorrect billing codes, duplicate submission, and third-party liability issues. For facilities in Philadelphia County, inadvertent cross-billing between Keystone First and CBH is one of the most common and costly billing errors.

Key Contact Information

Keystone First serves: Philadelphia, Bucks, Chester, Delaware, and Montgomery counties, Pennsylvania

• Provider Portal: https://providers.keystonefirstpa.com ↗ (Keystone First-specific provider resources)
• Transaction Portal: NaviNet — https://navinet.navimedix.com ↗ (primary platform for eligibility, authorization, claims for all AmeriHealth Caritas plans including Keystone First)
• Credentialing: CAQH ProView ( https://proview.caqh.org ↗ ) plus Pennsylvania PROMISe enrollment; contact Keystone First provider enrollment through providers.keystonefirstpa.com
• PA State Medicaid Enrollment: PROMISe — Pennsylvania Department of Human Services provider enrollment portal
• Philadelphia CBH Carve-Out: Community Behavioral Health — cbhphilly.org (for Philadelphia County behavioral health carve-out authorization and billing)
• Prior Authorization: Submit through NaviNet, fax, or Keystone First UM phone line listed in the provider manual and on the member’s insurance card
• Verification of Benefits: PROMISe for state enrollment confirmation + NaviNet for plan-specific benefits; contact provider services for CBH carve-out determination in Philadelphia
• Claims Submission: Electronic 837I / 837P via clearinghouse (Keystone First-specific payer ID) or NaviNet
• Parent Organization: AmeriHealth Caritas — amerihealthcaritas.com

Frequently Asked Questions

Keystone First is the Medicaid managed care brand that AmeriHealth Caritas uses to serve southeastern Pennsylvania. It is not a separate company — it is one of several regional brand names under which AmeriHealth Caritas (a joint venture of Independence Health Group and Blue Cross Blue Shield of Michigan) delivers Medicaid managed care. In southeastern Pennsylvania, AmeriHealth Caritas brands include Keystone First (serving the five-county Philadelphia-area region) and AmeriHealth Caritas Pennsylvania (serving other parts of the state). Providers who want to contract with Keystone First are contracting with the AmeriHealth Caritas family of companies, and credentialing with one AmeriHealth Caritas subsidiary does not automatically extend network participation to another. A separate application is required for Keystone First even if you are already credentialed with another AmeriHealth Caritas plan.

Keystone First serves the five-county southeastern Pennsylvania region historically associated with the Philadelphia metropolitan area — Philadelphia, Bucks, Chester, Delaware, and Montgomery counties. Providers located or seeking to serve members in these five counties should apply to Keystone First for network participation. Providers in other parts of Pennsylvania may need to apply to AmeriHealth Caritas Pennsylvania or another MCO serving the applicable county. Confirm current county-to-plan assignments through the Pennsylvania Department of Human Services (PA DHS) managed care enrollment guidance, as county assignments can change with Medicaid contract renewals.

Yes, subject to Pennsylvania's Section 1115 SUD waiver. Pennsylvania has an active 1115 SUD demonstration waiver that allows Medicaid payment for short-term residential SUD treatment in qualifying facilities with more than 16 beds (IMD facilities). Keystone First covers residential SUD levels of care consistent with the waiver terms, including ASAM 3.1 (clinically managed low-intensity residential), 3.5 (clinically managed high-intensity residential), and 3.7 (medically monitored intensive inpatient) where clinically indicated, subject to length-of-stay limits typically around 30 days per episode. Prior authorization is required for all residential levels, and concurrent reviews are conducted throughout the stay. Facilities must hold current Pennsylvania Bureau of Drug and Alcohol Programs (BDAP) licensure or the applicable Department of Drug and Alcohol Programs (DDAP) certification for the level of care provided.

Keystone First, like all AmeriHealth Caritas plans, uses NaviNet (navinet.navimedix.com) as its primary provider portal platform. NaviNet supports eligibility and benefits verification, prior authorization submission and status tracking, claim submission and status inquiry, and access to state-specific provider manuals and billing guides. Providers must register for a NaviNet account to transact with Keystone First electronically. NaviNet is shared across AmeriHealth Caritas plans, so a provider already registered for one AmeriHealth Caritas plan can access Keystone First transactions through the same NaviNet login. Contact Keystone First provider services or visit providers.keystonefirstpa.com for NaviNet registration instructions.

Timely filing for Keystone First Medicaid claims is governed by the Pennsylvania Medicaid MCO contract and your Keystone First provider agreement. Pennsylvania Medicaid MCO contracts commonly allow initial claim submission within 95 days of the date of service, though provider agreements may specify a different window. Corrected claims and coordination-of-benefits submissions have their own separate timely filing requirements. Some situations — such as coordination of benefits where another carrier paid first — may allow additional time measured from the primary payer's determination date. Reference the current Keystone First provider manual or your provider agreement for the exact deadline. Late Medicaid claims have very limited recourse under Pennsylvania Medicaid rules, so build timely filing tracking into your billing workflow.

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