Question: The hospital admitted a Medicare patient three days ago, and she underwent emergency surgery today. Would this surgery fall under Medicare Part A or Medicare Part B? Can you bill out ICD-10-PCS and CPT® codes to Medicare Part B? Illinois Subscriber Answer: There are numerous answers to this question, and each one ultimately ends with: it depends. Medicare Part A is hospital insurance. According to medicare.gov, Medicare Part A "covers inpatient hospital stays, care in a skilled nursing facility, hospice care, and some home health care." On the other hand, Medicare Part B falls under what you traditionally know as health insurance. According to medicare.gov, Medicare Part B "covers certain doctors' services, outpatient care, medical supplies, and preventive services." In short, Medicare Part A covers inpatient services billed out by the hospital. In addition to some surgical procedures, Medicare Part A covers basic hospital/skilled nursing facility services such as: On the other hand, Medicare Part B covers two particular types of physician services according to medicare.gov: When it comes to inpatient services, you can follow by a simple algorithm to determine whether or not the services rendered are billed out to Medicare Part A or Medicare Part B. If the services are billed out to an individual physician's national provider identifier (NPI), then you can immediately conclude that the charges will be billed to Part B. On the other hand, if the services are billed out to the hospital's NPI, then you are dealing with a Part A claim. In the example above, unless you are billing out from within the hospital (in which case you would only be billing to Part A), then the surgery performed by the physician will be billed out to his or her own NPI. As long as the physician is not a hospital employee, you will bill out for inpatient surgical services to Medicare Part B under the physician's NPI. For inpatient and emergency surgical services, most physician's will contract with the hospital, which will result in billing out under their own NPI. For the last part of your question, ICD-10-PCS services are exclusive to Medicare Part A facility billing. You may not bill out ICD-10-PCS to Medicare Part B for provider services and you may not bill out CPT® codes to Medicare Part A.