Coverage of these codes is payer-specific, so you should check to see if the payer has any guidelines in writing. For instance, there may be rules about which codes are covered or that the codes may be used only in addition to E/M codes. Before coding 99058, review the intent of the code (in all caps, next to last paragraph below).
CPT® Assistant. August 2010; Volume 20: Issue 8, states, “Codes 99050-99051 are not limited to a specific type of services (eg, preventive medicine, maintenance of chronic health issues, urgent care).”
“The guidelines to the Special Services, Procedures, and Reports subsection indicate that while these codes are typically reported with only one code per encounter, there may be occasions in which more than one of the Special Services codes can be appropriately reported due to the dual nature of these codes, ie, used in reporting unusual times and sites in providing services.”
“An example of a situation when reporting more than one Special Services code would be appropriate is when the patient must be seen on an emergency basis in an office that has regularly scheduled evening, weekend, or holiday office hours. In this example, both codes 99051 and code 99058, Service(s) provided on an emergency basis in the office, which disrupts other scheduled office services, in addition to basic service, would be reported, in addition to the code or codes for the services performed.”
The exact CPT guideline is: “Codes 99050-99060 are reported in addition to an associated basic service. Do not append modifier 51 to 99050-99060. Typically only a single adjunct code from among 99050-99060 would be reported per patient encounter. However, there may be circumstances in which reporting multiple adjunct codes per patient encounter may be appropriate.”
CPT® Assistant. August 2006 offers this Clinical Example (99051): “A patient presents with a cough and fever on a weekend afternoon to an office with regularly scheduled weekend and evening hours. CPT code 99051 is reported in addition to the basic service.”
The same article states (caps added), “CPT code 99058 reports office services provided on an emergency basis that disrupt other scheduled office services. THIS CODE IS REPORTED FOR THOSE OFFICE PATIENTS WHOSE CONDITION, IN THE CLINICAL JUDGMENT OF THE PHYSICIAN, WARRANTS THE PHYSICIAN'S INTERRUPTING HIS OR HER CARE OF ANOTHER PATIENT TO DEAL WITH THE EMERGENCY. THIS CODE IS NOT REPORTED WHEN THE PHYSICIAN'S USUAL PRACTICE IS TO HAVE TIME SLOTS AVAILABLE IN THE SCHEDULE AND PATIENTS ARE FIT INTO THAT SCHEDULE.”
It gives this Clinical Example (99058): “A patient presents to the physician's office and requires unscheduled emergency care (eg, new onset dyspnea and cyanosis). CPT code 99058 is reported in addition to the basic service.”