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CO-60 Denial Code: Outpatient Services Near Inpatient Stay

CO-60 means the payer won't pay outpatient services performed within a set period before or after an inpatient stay, because those services are treated as part of the inpatient payment. It's common with Medicare's pre-admission payment window for hospitals.

Quick facts

Code
CO-60 (CARC 60)
Status
Active In use since January 1, 1995; last modified June 1, 2008.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The standard group. The provider can't bill the patient; the services are included in, or must be billed with, the inpatient claim.
Official description
Charges for outpatient services are not covered when performed within a period of time prior to or after inpatient services.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-60 means

CARC 60 says charges for outpatient services are not covered when performed within a period of time prior to or after inpatient services. Some payers treat outpatient services close to an inpatient stay as part of that stay. Instead of paying them separately, they expect the services to be included in the inpatient payment.

Medicare’s version is the payment window, often called the 3-day rule. Diagnostic services, and related non-diagnostic services, furnished by the admitting hospital or an entity it wholly owns or operates within the window before admission are bundled into the inpatient claim. Commercial and Medicaid plans may have their own windows before or after admission, so check the contract and payer policy.

Common causes

  • Pre-admission testing billed on an outpatient claim when the patient is admitted within the window.
  • Emergency department visit billed separately when the patient is admitted to the same hospital.
  • Hospital-owned clinic services in the window not bundled into the inpatient claim.
  • Wrong dates of service placing an unrelated outpatient visit inside the window.
  • Post-discharge services under payer policies that include a window after discharge.

How to fix it

  1. Compare dates of the outpatient service with the inpatient admission and discharge dates.
  2. Check whether the service is related to the admission under the payer’s rules, and whether the provider is the admitting hospital or a wholly owned or operated entity.
  3. If it belongs in the window, add the charges to the inpatient claim, often by adjusting the inpatient bill.
  4. If it’s unrelated or outside the window, correct dates or add documentation or condition codes the payer accepts, then resubmit or request reprocessing.
  5. For professional claims, confirm whether modifier PD applies.
  6. Don’t bill the patient for CO-60 amounts.

How to prevent it

  • Check for recent or upcoming admissions before billing outpatient services.
  • Hold outpatient claims briefly when admission is likely, so they can be combined if needed.
  • Coordinate between hospital-owned clinics and the hospital billing office on payment window rules.
  • Train staff on each payer’s window rules, not just Medicare’s.

Specialty notes

Hospital-owned physician practices, pre-admission testing departments, and emergency departments deal with CO-60 most. Independent practices that the hospital doesn’t wholly own or wholly operate generally aren’t subject to the Medicare payment window.

Remark codes that may appear with CO-60

  • MA133 (Claim overlaps inpatient stay.): The claim overlaps an inpatient stay. Rebill only services rendered outside the stay.
  • N47 (Claim conflicts with another inpatient stay.): The claim conflicts with another inpatient stay.
  • CO-97 (The benefit for this service is included in the payment/allowance for another service/procedure that has already been adjudicated.): Payment included in another service's allowance, a broader bundling code.
  • CO-190 (Payment is included in the allowance for a Skilled Nursing Facility (SNF) qualified stay.): Payment included in a skilled nursing facility qualified stay.
  • CO-232 (Institutional Transfer Amount.): Institutional transfer amount.
  • CO-B20 (Procedure/service was partially or fully furnished by another provider.): The service was partially or fully furnished by another provider.

CO-60 FAQ

What is the Medicare payment window?

Often called the 3-day (or 72-hour) rule, it requires hospitals to bundle certain outpatient services provided to a patient in the days before an inpatient admission into the inpatient claim. The window is generally 3 days for hospitals paid under the inpatient prospective payment system and 1 day for certain other hospital types, and it applies to the admitting hospital and entities it wholly owns or operates.

Does CO-60 apply to physicians?

Physician professional services are generally billed separately. However, for services in the window provided in an entity wholly owned or operated by the hospital, Medicare pays the professional service at the facility rate, which physicians report with modifier PD.

How do I fix CO-60?

Check whether the outpatient services fall within the payment window and relate to the admission. If they do, include them on the inpatient claim. Under Medicare's rule, diagnostic services in the window are bundled whether or not they relate to the admission; only clinically unrelated non-diagnostic services are excluded. If the services fall outside the window or are unrelated non-diagnostic services, correct the dates or document the distinction and resubmit.