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Ambulatory Surgery Centers (ASC) Billing Manual

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Ambulatory Surgery Centers (ASCs)

The Department of Health Care Policy and Financing (the Department) periodically modifies billing information. Therefore, the information in this manual is subject to change, and the manual is updated as new billing information is implemented.

Providers must be enrolled as a Health First Colorado (Colorado's Medicaid program) provider in order to:

  • Treat a Health First Colorado member
  • Submit claims for payment to Health First Colorado

Medical services provided in Ambulatory Surgery Centers (ASCs) are a benefit of Health First Colorado.

Ambulatory Surgery Centers are distinct entities that provide a surgical setting for members who do not require hospitalization. If the ASC is part of a hospital, the ASC portion must be physically separated from all other health services offered at the hospital.

To receive payment, the center must be certified as an ASC by the Centers for Medicare & Medicaid Services (CMS), licensed as an ASC by the Colorado Department of Public Health and Environment (CDPHE) and enrolled in Health First Colorado.

Providers should refer to the Code of Colorado Regulations, Program Rules (10 CCR 2505-10), for specific information when providing care in an ASC.

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General Billing Information

Refer to the General Provider Information Manual for general billing information.

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ASC Authorized Services

Services must be reported using HCPCS surgical procedure codes. This manual contains a complete list of the Health First Colorado-approved ASC procedure codes effective January 1, 2026. The list is divided into related groups for payment. Only surgical procedure codes that are published in this manual are ASC Health First Colorado benefits. Visit the Rate and Fee Schedule web page for a list of all ASC codes with their respective groupers.

Health First Colorado bulletins notify providers when annual coding updates are implemented.

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Reimbursement

For payment purposes, ASC surgical procedures are grouped into 10 categories. The Health First Colorado reimbursement rates are the lower of billed charges or the maximum allowable payment by group. Visit the Provider Rates and Fee Schedule web page on the Department's website for current ASC group rates.

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Health First Colorado Program Payment Calculation

Submitted charges must represent usual and customary charges. Do not adjust charges to correspond to the anticipated Medicaid payment.

Health First Colorado providers must agree to accept Health First Colorado reimbursement as payment in full for benefit services. Health First Colorado members may not be billed for charges that exceed the Health First Colorado allowance. The Medicaid Management Information System (interChange) calculates payment as the provider's billed charge or the established rate for the group, whichever is less.

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Multiple Procedures

When multiple procedures are performed during the same session, payment will correspond to the procedure with the highest allowed grouper amount. Additional payment is not available for multiple or subsequent procedures performed on the same date of service.

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Medicare Crossover Payment

Health First Colorado payment for Part B Medicare crossover claims is made as follows:

  1. The sum of reported Medicare deductible and coinsurance or
  2. The Health First Colorado allowed benefit minus the Medicare payment, whichever is less. Third Party liability payments and Health First Colorado copay amounts, as applicable, will be subtracted after the crossover allowed payment has been determined.

If the amount paid by Medicare equals or is greater than the Health First Colorado benefit, the Health First Colorado Program makes no additional payment. This method of determining payment is commonly referred to as "lower-of" pricing.

Note: Except for applicable Health First Colorado copayment amounts, unpaid balances cannot be billed to the Health First Colorado member or the member's family.

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Services and Items Included at a Minimum in the ASC Reimbursement

  1. Use of the facilities where the surgical procedures are performed
  2. Nursing, technician and related services
  3. Drugs, biologicals, surgical dressings, supplies, splints, casts and appliances and equipment directly related to the provision of surgical procedures
  4. Diagnostic and therapeutic items and services directly related to the provision of a surgical procedure
  5. Administrative, record keeping and housekeeping items and services
  6. All blood products (whole blood, plasma, platelets, etc.)
  7. Materials for anesthesia
  8. Intra-ocular lenses (IOLs)
  9. Supervision of the services of an anesthetist by the operating surgeon

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Services That May Be Billed Separately

The following services/items are not included in the ASC rate and may be billed separately by the actual provider of services.

  1. Physician services
  2. Anesthetist services
  3. Laboratory, radiology or diagnostic procedures (other than those directly related to performance of the surgical procedure)
  4. Prosthetic devices (except IOLs)
  5. Ambulance services
  6. Leg, arm, back and neck braces
  7. Artificial limbs
  8. Durable medical equipment for use in the member's home

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Billing Procedures

Ambulatory Surgical Center facility claims are submitted as an 837 Professional (837P) electronic transaction or on the CMS 1500 paper claim form. Claim completion instructions are described in the above Billing Information. The following instructions are specific to ASC facility services claims. Ambulatory Surgical Center information does not apply to other provider types.

Ambulatory Surgical Center claims should be submitted electronically. Electronic claims submission reduces billing expense and claims processing time. Information about electronic claims submission may be obtained from Electronic Data Interchange (EDI) Support, Monday through Friday from 8:00 a.m. to 5:00 p.m. Mountain Time (MT).

Procedure codes: ASCs identify services using HCPCS surgical procedure codes. During claim processing, the surgical code is linked to an appropriate ASC group for payment calculation.

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Billing Information

The ASC is responsible for obtaining required billing information from the surgeon. ASC providers are required to verify Health First Colorado eligibility before services are rendered. If eligibility is not verified, payment may be denied.

ICD-10-CM diagnosis: The diagnosis field(s) must be completed with an appropriate ICD-10-CM diagnosis code(s).

Place of service: Complete the Place Of Service (POS) field with a "24" for ASC facility charges.

Note: Electronic billers should consult the software instructions to assure that POS coding is submitted properly.

Rendering provider: Complete with the NPI number assigned to the operating surgeon.

Referring provider: If the member is enrolled in the Primary Care Physician (PCP) program and the operating surgeon is not the PCP, the PCP's NPI number must be entered in this field. PCP-enrolled members must obtain PCP referral if surgical services are performed by a physician other than the PCP. If the member does not have an assigned PCP, this field may be left blank.

Sterilization procedures: All sterilization claims must have an attached copy of a properly completed MED-178 sterilization consent form. The surgeon is responsible for providing a copy of the MED-178 to the ASC. Claims without a properly completed MED-178 are denied. Refer to the Obstetrical Care Billing Manual for complete billing requirements.

Hysterectomy procedures: Hysterectomy procedures are a benefit of Health First Colorado when performed solely for medical reasons. Hysterectomy is not a benefit if the procedure is performed solely for the purpose of sterilization, or if there was more than one (1) purpose for the procedure and it would not have been performed but for the purpose of sterilization. Refer to the Obstetrical Care Billing Manual for complete billing requirements.

Medicare crossover claims: Health First Colorado pays the Medicare deductible and coinsurance or the Health First Colorado-allowed benefit minus the Medicare payment, whichever is less. If Medicare's payment equals or is more than the Health First Colorado allowed benefit, crossover claims are paid at zero (0).

Most Medicare crossover claims are transmitted electronically from Medicare to Health First Colorado. If a Medicare claim does not cross automatically, the provider is responsible for submitting a "hard copy crossover" claim on the CMS 1500 paper claim form. Refer to the end of the manual for an example of a completed paper crossover claim.

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ASC Group 1

ASC Group 1

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ASC Group 2

ASC Group 2

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ASC Group 3

ASC Group 3

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ASC Group 4

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ASC Group 5

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ASC Group 6

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ASC Group 7

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ASC Group 8

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ASC Group 9

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ASC Group 10

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ASC Group 11

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CMS 1500 Paper Claim Reference Table

The following paper form reference table shows required, optional and conditional fields and detailed field completion instructions for the CMS 1500 claim form.

CMS Field Number and LabelField is?Instructions
1. Insurance TypeRequiredPlace an "X" in the box marked as Medicaid.
1a. Insured's ID NumberRequiredEnter the member's seven (7)-digit Health First Colorado ID number as it appears on the Health First Colorado Identification card. 
Example: A123456.
2. Patient's NameRequiredEnter the member's last name, first name and middle initial.
3. Patient's Date of Birth/SexRequiredEnter the member's birth date using two (2) digits for the month, two (2) digits for the date and two (2) digits for the year. Example: 010125 for January 1, 2025.

Place an "X" in the appropriate box to indicate the sex of the member.
4. Insured's NameConditionalComplete if the member is covered by a Medicare health insurance policy.

Enter the insured's full last name, first name and middle initial. If the insured used a last name suffix (e.g., Jr, Sr), enter it after the last name and before the first name.
5. Patient's AddressNot Required 
6. Patient's Relationship to InsuredConditionalComplete if the member is covered by a commercial health insurance policy. Place an "X" in the box that identifies the member's relationship to the policyholder.
7. Insured's AddressNot Required 
8. Reserved for NUCC UseNot Required 
9. Other Insured's NameConditionalIf field 11d is marked "YES", enter the insured's last name, first name and middle initial.
9a. Other Insured's Policy or Group NumberConditionalIf field 11d is marked "YES", enter the policy or group number.
9b. Reserved for NUCC Use  
9c. Reserved for NUCC Use  
9d. Insurance Plan or Program NameConditionalIf field 11D is marked "YES", enter the insurance plan or program name.
10a-c. Is patient's condition related to?ConditionalWhen appropriate, place an "X" in the correct box to indicate whether one (1) or more of the services described in field 24 are for a condition or injury that occurred on the job, as a result of an auto accident or other.
10d. Reserved for Local Use  
11. Insured's Policy, Group or FECA NumberConditionalComplete if the member is covered by a Medicare health insurance policy.

Enter the insured's policy number as it appears on the ID card. Only complete if field 4 is completed.
11a. Insured's Date of Birth, SexConditionalComplete if the member is covered by a Medicare health insurance policy.

Enter the insured's birth date using two (2) digits for the month, two (2) digits for the date and two (2) digits for the year. Example: 010125 for January 1, 2025.

Place an "X" in the appropriate box to indicate the sex of the insured.
11b. Other Claim IDNot Required 
11c. Insurance Plan Name or Program NameNot Required 
11d. Is there another Health Benefit Plan?ConditionalWhen appropriate, place an "X" in the correct box. If marked "YES", complete 9, 9a and 9d.
12. Patient's or Authorized Person's signatureRequiredEnter "Signature on File", "SOF" or legal signature. If there is no signature on file, leave blank or enter "No Signature on File".

Enter the date the claim form was signed.
13. Insured's or Authorized Person's SignatureNot Required 
14. Date of Current Illness Injury or PregnancyConditionalComplete if information is known. Enter the date of illness, injury or pregnancy, (date of the last menstrual period) using two (2) digits for the month, two (2) digits for the date and two (2) digits for the year. Example: 010125 for January 1, 2025.

Enter the applicable qualifier to identify which date is being reported.
431 - Onset of Current Symptoms or Illness
484 - Last Menstrual Period
15. Other Date NotNot Required 
16. Date Patient Unable to Work in Current OccupationNot Required 
17. Name of Referring PhysicianConditional 
17b. NPI of Referring PhysicianRequiredRequired in accordance with Program Rule 8.125.8.A
18. Hospitalization Dates Related to Current ServiceNot required 
19. Additional Claim InformationConditional 
20. Outside Lab?
$ Charges		ConditionalComplete if all laboratory work was referred to and performed by an outside laboratory. If this box is checked, no payment will be made to the physician for lab services. Do not complete this field if any laboratory work was performed in the office.

Practitioners may not request payment for services performed by an independent or hospital laboratory.
21. Diagnosis or Nature of Illness or InjuryRequiredEnter at least one (1) but no more than 12 diagnosis codes based on the member's diagnosis/condition.

Enter applicable ICD-10 indicator.
22. Medicaid Resubmission CodeConditionalList the original reference number for resubmitted claims.

When resubmitting a claim, enter the appropriate bill frequency code in the left- hand side of the field.
7 - Replacement of prior claim
8 - Void/Cancel of prior claim
This field is not intended for use for original claim submissions.
23. Prior AuthorizationNot Required 
24. Claim Line DetailInformationThe paper claim form allows entry of up to six (6) detailed billing lines. Fields 24A through 24J apply to each billed line.

Do not enter more than six (6) lines of information on the paper claim. If more than six (6) lines of information are entered, the additional lines will not be entered for processing.

Each claim form must be fully completed (totaled).

Do not file continuation claims (e.g., Page 1 of 2).
24A. Dates of ServiceRequired

The field accommodates the entry of two (2) dates: a "From" date of services and a "To" date of service. Enter the date of service using two (2) digits for the month, two (2)digits for the date and two (2) digits for the year. Example: 010125 for January 1, 2025.

or

Span dates of service

Practitioner claims must be consecutive days.
Single Date of Service: Enter the six (6)-digit date of service in the "From" field. Completion of the "To" field is not required. Do not spread the date entry across the two (2) fields.

Span billing: permissible if the same service (same procedure code) is provided on consecutive dates.
Supplemental Qualifier
To enter supplemental information, begin at 24A by entering the qualifier and then the information.
ZZ - Narrative description of unspecified code
N4 - National Drug Codes

  • Enter NDC qualifier N4 (left-justified), immediately followed by the 11-digit NDC numeric code.
  • Enter one (1) space for separation.
  • Enter the appropriate qualifier for the correct dispensing NDC unit of measure (UN - Units, ML - Milliliter, GR - Gram or F2 - International Unit), immediately followed by the quantity (number of NDC units).

VP - Vendor Product Number
OZ - Product Number
CTR - Contract Rate
JP - Universal/National Tooth Designation
JO - Dentistry Designation System for Tooth and Areas of Oral Cavity

24B. Place of ServiceRequiredEnter the Place of Service (POS) code that describes the location where services were rendered. Health First Colorado accepts the CMS place of service codes.
24 - ASC
24C. EMGConditionalEnter a "Y" for YES or leave blank for NO in the bottom, unshaded area of the field to indicate the service is rendered for a life-threatening condition or one (1) that requires immediate medical intervention.

If a "Y" for YES is entered, the service on this detail line is exempt from co-payment requirements.
24D. Procedures, Services or SuppliesRequiredEnter the procedure code that specifically describes the service for which payment is requested.
24D.RequiredEnter the HCPCS procedure code that specifically describes the service for which payment is requested.

All procedures must be identified with codes in the current edition of Physicians Current Procedural Terminology (CPT). CPT is updated annually.

HCPCS Level II Codes
The current Medicare coding publication (for Medicare crossover claims only).

Only approved codes from the current CPT or HCPCS publications will be accepted.

Telemedicine
For originating provider use procedure code Q3014.

For distant provider use procedure code + modifier GT.
24D. ModifierNot Required 
24E. Diagnosis PointerRequiredEnter the diagnosis code reference letter (A-L) that relates the date of service and the procedures performed to the primary diagnosis.

At least one (1) diagnosis code reference letter must be entered.

When multiple services are performed, the primary reference letter for each service should be listed first, other applicable services should follow.

This field allows for the entry of four (4) characters in the unshaded area.
24F. $ ChargesRequiredEnter the usual and customary charge for the service represented by the procedure code on the detail line. Do not use commas when reporting dollar amounts. Enter 00 in the cents area if the amount is a whole number.

Some CPT procedure codes are grouped with other related CPT procedure codes. When more than one (1) procedure from the same group is billed, special multiple pricing rules apply.

The base procedure is the procedure with the highest allowable amount. The base code is used to determine the allowable amounts for additional CPT surgical procedures when more than one (1) procedure from the same grouping is performed.

Submitted charges cannot be more than charges made to non-Health First Colorado covered individuals for the same service.

Do not deduct Health First Colorado co-pay or commercial insurance payments from the usual and customary charges.
24G. Days or UnitsRequiredEnter the number of services provided for each procedure code.
Enter whole numbers only- do not enter fractions or decimals.
24H. EPSDT/Family PlanConditionalEPSDT (shaded area)
For Early and Periodic Screening, Diagnosis and Treatment-related services, enter the response in the shaded portion of the field as follows:
AV - Available- Not Used
S2 - Under Treatment
ST - New Service Requested
NU - Not Used

Family Planning (unshaded area)
If the service is Family Planning, enter "Y" for YES or "N" for NO in the bottom, unshaded area of the field.
24I. ID QualifierNot Required 
24J. Rendering Provider ID #Not Required 
25. Federal Tax ID NumberNot Required 
26. Patient's Account NumberOptionalEnter information that identifies the member or claim in the provider's billing system. Submitted information appears on the Remittance Advice (RA).
27. Accept Assignment?RequiredThe accept assignment indicates that the provider agrees to accept assignment under the terms of the payer's program.
28. Total ChargeRequiredEnter the sum of all charges listed in field 24F. Do not use commas when reporting dollar amounts. Enter 00 in the cents area if the amount is a whole number.
29. Amount PaidConditionalEnter the total amount paid by Medicare or any other commercial health insurance that has made payment on the billed services.

Do not use commas when reporting dollar amounts. Enter 00 in the cents area if the amount is a whole number.
30. Rsvd for NUCC Use  
31. Signature of Physician or Supplier Including Degrees or CredentialsRequiredEach claim must bear the signature of the enrolled provider or the signature of a registered authorized agent.

Each claim must have the date the enrolled provider or registered authorized agent signed the claim form. Enter the date the claim was signed using two (2) digits for the month, two (2) digits for the date and two (2) digits for the year. Example: 010125 for January 1, 2025.

Unacceptable signature alternatives:
Claim preparation personnel may not sign the enrolled provider's name.
Initials are not acceptable as a signature.
Typed or computer printed names are not acceptable as a signature.
"Signature on file" notation is not acceptable in place of an authorized signature.
32. Service Facility Location Information
32a- NPI Number
32b- Other ID #		RequiredEnter the name, address and ZIP code of the individual or business where the member was seen or service was performed in the following format:
1st Line Name
2nd Line Address
3rd Line City, State and ZIP Code
If the Provider Type is not able to obtain an NPI, enter the eight (8)-digit Health First Colorado provider number of the individual or organization.
33. Billing Provider
Info & Ph #		RequiredEnter the name of the individual or organization that will receive payment for the billed services in the following format:
1st Line Name
2nd Line Address
3rd Line City, State and ZIP Code
33a- NPI NumberRequired 
33b- Other ID # If the Provider Type is not able to obtain an NPI, enter the eight (8)-digit Health First Colorado provider number of the individual or organization.

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CMS 1500 ASC Claim Example

CMS 1500 ASC Claim Example

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CMS 1500 ASC Crossover Claim Example

CMS 1500 ASC crossover Claim Example

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Sterilizations, Hysterectomies and Abortions

Refer to the Obstetrical Care Billing Manual located on the Billing Manuals web page under the CMS 1500 drop-down for more information on sterilization, hysterectomies and abortions.

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Timely Filing

Refer to the General Provider Information Manual located on the Billing Manuals web page under the General Provider Information drop-down for more information on timely filing policy, including the resubmission rules for denied claims.

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ASC Revisions Log

Revision DateAddition/ChangesMade by
12/1/2016Manual revised for interChange implementation. For manual revisions prior to 12/1/2016, please refer to Archive.HPE (now DXC)
12/27/2016Updates based on Colorado iC Stage II Provider Billing Manual Comment Log v0_2.xlsx.HPE (now DXC)
1/10/2017Updates based on Colorado iC Stage II Provider Billing Manual Comment Log v0_3.xlsx.HPE (now DXC)
1/19/2017Updates based on Colorado iC Stage II Provider Billing Manual Comment Log v0_4.xlsxHPE (now DXC)
1/26/2017Updates based on Department 1/20/2017 approval email.HPE (now DXC)
5/22/2017Updates based on Fiscal Agent name change from HPE to DXCDXC
2/9/2018Removed NDC supplemental qualifier - not relevant for ASC providersDXC
6/25/2018Updated billing and timely to point to general manualHCPF
12/21/2018Clarification to signature requirementsHCPF
5/24/2019Updated procedure groups, removed pilot program and rate table sectionsHCPF
1/7/2020Converted to web pageHCPF
4/21/2020Added ASC Group 11HCPF
6/17/2020Updated procedure groupsHCPF
9/10/2020Added Line to Box 32 under the CMS 1500 Paper Claim Reference TableHCPF
12/1/2021Updated allowed proceduresHCPF
5/10/2022Added approved procedures, removed outdated anesthesia languageHCPF
5/31/2022Removed extra zero from group 4 code 67904HCPF
7/20/2022Added link to Rates page for list of ASC codes and groupersHCPF
10/14/2022Removed Phone Number to EDI. Linked verbiage to Provider Help web page.HCPF
3/1/2023Updated procedures based on 2023 HCPCSHCPF
5/18/2023Corrected typo in table 3HCPF
3/17/2025Updated with 2025 HCPCSHCPF
1/5/2026Updated covered surgical proceduresHCPF

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