Hello,
keep in mind the because we code a procedure for the hospital it doesn't mean is "inpatient" coding.
Any place (clinic, hospital or any type of healthcare facility) that uses a CPT book or HCPCS to code is outpatient coding even for hospital services.
ICD-10-PCS is precisely for inpatient coding, now when it comes to understanding the billing portion just as stated by Pam, when coding especially for the doctors services or the "professional" services you are coding CPT. When you are billing for the hospital (which includes the hospital bed, room, nursing services, medication, monitoring) anything that is not the doctor's services, then a UB04 bill is created for this services as for outpatient (CPT) will be the CMS-1500.