What is Health First Colorado? CPT Code Billing Guide for Providers

Health First Colorado CPT Code Billing  is Colorado’s Medicaid program, administered by HCPF. CPT code billing for this program requires providers to be properly enrolled, use the correct codes and modifiers, follow the timely filing rules of 12 months, check prior authorisation requirements before services, verify eligibility before every visit, and reference the official Health First Colorado fee schedule for current rates.

The 1.6% rate increase effective July 1, 2025 applies to most services, with behavioral health rates including $159.67 for 90791 and $134.51 for 90837.

 Providers who skip eligibility verification, use wrong codes or modifiers, miss prior authorizations, or file late will face automatic denials.

What is Health First Colorado?

Health First Colorado is the official name for Colorado’s Medicaid program. It serves more than 1.8 million Coloradans and is administered by the Colorado Department of Health Care Policy & Financing (HCPF). If you bill for services provided to low-income patients in Colorado, you are dealing with Health First Colorado.

The program operates through two primary payment pathways: Fee-for-Service (FFS) and Managed Care through Regional Accountable Entities (RAEs). Most behavioral health services, for example, are covered through RAEs rather than FFS. Before you submit any claim, you must run a member eligibility query in the HCPF Provider Web Portal to determine which pathway applies to your patient. Billing the wrong payer is one of the leading causes of claim denial.

Health First Colorado CPT Code Billing

CPT stands for Current Procedural Terminology. These are five-digit codes that describe every medical service you provide to a patient. When you submit a claim to Health First Colorado, you need four things: the correct CPT code for the service, the correct diagnosis code (ICD-10), the right provider information, and the correct place of service code. Get any of these wrong, and the claim comes back denied.

Health First Colorado follows the standard AMA CPT code set, but the state publishes its own fee schedules that determine exactly how much Medicaid will reimburse for each code. These rates are updated twice per year, and providers are responsible for checking the current fee schedule before billing.

Critical Provider Enrollment Requirements

Before you can bill a single claim, you must be enrolled with Health First Colorado and maintain an active NPI in the HCPF system. 

Enrollment is managed through the Colorado interChange (MMIS) Provider Web Portal. If you are not correctly enrolled, or if the information on your claim does not match your enrollment record, your claim will be denied.

There is a specific requirement that causes many denials. All outpatient physical and occupational therapy providers must enter the NPI of the ordering provider on every claim.

This applies to both CMS 1500 paper claims (field 17b) and electronic submissions (loop 2420, with qualifier DK for Ordering, DN for Referring, or DQ for Supervising). If you miss this NPI, the claim denies automatically.

Starting in late 2025 and early 2026, RAEs and MCOs began denying claims that do not meet these enrollment requirements. 

Colorado Access started denying incorrectly submitted claims on December 1, 2025. By January 5, 2026, most other RAEs including Colorado Community Health Alliance, Denver Health, Kaiser Permanente, Northeast Health Partners, and Rocky Mountain Health Plans began denying these claims as well.

2025-2026 Rate Updates

A 1.6% across-the-board rate increase took effect July 1, 2025, following approval during the 2024 Colorado legislative session. This increase applies to most Fee-for-Service benefits, including physician services, dental care, and behavioral health, and has been incorporated into the Colorado interchange system.

Here are sample behavioral health rates from October 2025 through June 2026:

These rates are subject to change. You can search current rates for any CPT code at the official HCPF fee schedule page: hcpf.colorado.gov/provider-rates-fee-schedule .

Evaluation and Management (E/M) CPT Codes

E/M codes (99202–99215 for office and outpatient visits) are among the most frequently billed codes in Colorado Medicaid. HCPF follows CMS guidelines for E/M service level selection, allowing providers to base the visit level on either Medical Decision Making (MDM) or Total Time on the date of service.

Important change since 2010: Colorado Medicaid no longer recognizes CPT consultation codes (99241–99245 for office and outpatient services; 99251–99255 for inpatient). Providers should use the appropriate E/M code reflecting where the visit occurred and the complexity rendered, consistent with Medicare policy.

Adults may receive one physical examination per year as a covered benefit. However, sports physicals are not a covered service under Health First Colorado.

Behavioral Health CPT Code Billing

Behavioral health services for nearly all Health First Colorado members are covered through Regional Accountable Entities (RAEs), not Fee-for-Service. The January 2025 HCPF State Behavioral Health Services (SBHS) Billing Manual is the authoritative source for mental health and substance use disorder billing.

Common Behavioral Health CPT Codes

EPSDT: Expanded Coverage for Members Under 21

Under federal Medicaid law (42 U.S.C. § 1396d(r)), Health First Colorado must provide Early and Periodic Screening, Diagnostic, and Treatment (EPSDT) benefits for all members under 21. This means any medically necessary service to correct or ameliorate a defect, physical or mental illness, or condition identified by screening must be covered, even if the service is not listed in Colorado’s standard State Medicaid Plan.

Effective January 1, 2024, Autism Spectrum Disorder services for members under 21 falls under this expanded mandate.

Modifiers in Colorado Medicaid Billing

Modifiers are two-digit codes added to a CPT code. They give Medicaid more information about how a service was performed. Using the wrong modifier or missing a required modifier is a common cause of claim denials.

Commonly used modifiers in Colorado Medicaid billing include:

Units of Service: Timed vs. Untimed Codes

Health First Colorado follows AMA guidelines distinguishing “timed” and “untimed” CPT codes. 

• Timed codes specify a direct time increment. For physical therapy and occupational therapy services, time is typically billed in 15-minute increments. Only time spent directly with the member counts. Pre-encounter documentation time, drive time, and administrative tasks are excluded.
• Untimed codes are billed as one unit per session regardless of duration. Most psychotherapy codes (90791, 90832, 90834, 90837) are untimed in the sense that each code represents a specific time range, and you bill one unit for the session.

Prior Authorization Requirements

Not every service requires prior authorization, but many specialty services, high-cost procedures, and some behavioral health services do. You must check before scheduling the service. Billing a service that requires prior authorization without having an approved authorization number on file will result in a denial.

Healthfirst (a specific health plan, not to be confused with Health First Colorado) announced prior authorization changes for certain codes effective April 1, 2026 and July 1, 2026. However, for Health First Colorado (Colorado Medicaid), prior authorization requirements are detailed in the individual service billing manuals and the Colorado Code of Regulations (10 CCR 2505-10).

Claim Submission: Forms and Timely Filing

For Health First Health Plans, providers must submit initial claims within 180 days of the date of service. Standard electronic claim forms are processed via clearinghouses using payer ID 77026. Missing this critical window can result in automatic timely filing denials, which are difficult to overturn

Acceptable Claim Forms

• CMS-1500: Used for professional services by doctors, therapists, and independent practitioners.
• UB-04 (CMS-1450): Used for institutional claims by hospitals and clinics.
• Member Reimbursement Form: Used directly by patients paying out-of-pocket and seeking reimbursement.

Timely Filing Guidelines

Deadlines dictate exactly when the payer must receive your clean claim:

• Initial Claim Submission: 180 days from the date of service. [1]
• Corrected Claims & Appeals: Generally limited to 90 to 180 days from the initial Explanation of Benefits (EOB) date. Always consult your specific provider contract for precise variance.
• Coordination of Benefits (COB): If Health First is the secondary payer, the timely filing limit starts from the date of the primary payer’s EOB.

Submission Methods & Resources

To ensure successful processing, utilize the following portals and tools:

• Electronic Submission: File claims electronically to speed up payment and track receipt. Verify system connectivity and clearinghouse options via the Health First Provider Portal.
• Payment Tracking: Review EFT and ERA enrollment options utilizing Zelis.
• Claim Disputes: If a claim was denied or improperly paid, submit a Provider Claim Dispute Request.

If you are trying to resolve a specific issue, I can help you with:

• Locating the correct form for your specific billing scenario.
• Drafting a formal appeal or dispute letter for a denial.
• Understanding Coordination of Benefits (COB) guidelines.

Timely Filing

Most Health First Colorado claims must be filed within 12 months of the date of service. Claims submitted after this period will be denied with EOB 1786. If you have a valid reason for late filing, you must attach documentation for review by the fiscal agent.

New Procedure Codes

When new procedure codes are released each year (such as the 2026 HCPCS updates), claims for those codes may suspend with EOB 0000 “This claim/service is pending for program review” while the Colorado interChange is updated. This review typically takes 30 to 60 days. Physician-administered drugs may take up to 90 days.

Claim Denials

Common reasons for claim denials in Colorado Medicaid include the wrong CPT code, no prior authorization, expired or inactive patient coverage, a missing modifier, duplicate claims, timely filing violations, and the provider not being properly enrolled.

Telehealth Billing

For telehealth services, Colorado Medicaid requires the appropriate modifier. Modifier GT indicates the service was provided via telehealth. Telehealth rules have expanded significantly, but you must still check the specific requirements for your service type and the patient’s plan.

Starting January 31, 2026, physical therapists generally cannot bill Medicare for telehealth services delivered to patients at home. However, Colorado Medicaid has its own telehealth policies. Always verify current rules before billing telehealth services.

Third-Party Liability and Coordination of Benefits

Providers cannot bill members for copays or deductibles assessed by third-party resources. Providers cannot bill members for the difference between commercial health insurance payments and billed charges when Health First Colorado does not make an additional payment.

A member’s commercial health insurance must be billed first. Lower-of pricing is used to calculate reimbursement from Health First Colorado.

How to Access the Official Health First Colorado Fee Schedule?

The official Health First Colorado fee schedule is available at hcpf.colorado.gov/provider-rates-fee-schedule . You can search rates by CPT code, provider type, or service category. The fee schedule is updated regularly, sometimes multiple times per year.

Rates for different service categories are available including Ambulatory Surgery Centers, Behavioral Health FFS, Child Health Plan Plus, Community First Choice, Dental, Dialysis, Home Health, Hospice, Hospital, Immunizations, and Transportation.

Frequently Asked Questions

What CPT codes does Health First Colorado cover?

Health First Colorado covers a wide range of CPT codes including E/M visits, behavioral health services, preventive care, home health, and telehealth. The complete list is available in the official fee schedule on the HCPF website.

What is the timely filing limit for Health First Colorado claims?

Most claims must be filed within 12 months of the date of service. Some situations like coordination of benefits may allow exceptions.

Do I need prior authorization for all Health First Colorado services?

No. Not all services require prior authorization. However, many specialty services, high-cost procedures, and some behavioral health services do. Always check before scheduling the service.

Why is my Health First Colorado claim being denied?

Common reasons include wrong CPT codes, missing modifiers, no prior authorization, the patient’s coverage was not active, or the claim was not filed on time. Verify eligibility before every visit and check your claim against the current fee schedule.

Where can I find the official fee schedule?

The official fee schedule is at hcpf.colorado.gov/provider-rates-fee-schedule . You can search by code or download complete schedules by provider type.

What is the difference between Health First Colorado and Colorado Medicaid?

There is no difference. Health First Colorado is the brand name for Colorado’s Medicaid program.