HCPCS Coding Interview Questions
Common Questions and Answers
Q: What is the difference between HCPCS Level I and Level II?
A: HCPCS Level I codes are CPT codes — five-digit numeric codes maintained by the AMA for physician procedures and services. HCPCS Level II codes are alphanumeric (letter + 4 digits) codes maintained by CMS for items and services not covered by CPT, including supplies, durable medical equipment, drugs administered in an office, orthotics, prosthetics, ambulance services, and vaccines.
Q: When would you use a J code?
A: J codes are used to bill for drugs that are administered other than orally — typically injections or infusions given in a physician office or outpatient facility. For example, J0696 is used to bill for ceftriaxone injections given in the clinic. You calculate units based on the dose given divided by the dose per code unit. If drug is wasted from a single-dose vial, you append modifier JW to the waste units.
Q: What is an ABN and when is it required?
A: An Advance Beneficiary Notice of Noncoverage is a written notice given to a Medicare patient before a service when Medicare is expected to deny payment. The ABN allows the patient to decide whether to proceed with the service and agree to pay out-of-pocket if Medicare denies. Without a signed ABN, providers cannot bill the patient when Medicare denies. You append modifier GA when an ABN is on file.
Q: What is the difference between RR and NU modifiers for DME?
A: RR indicates the item is being rented to the patient. NU indicates the item is new equipment being purchased. Certain DME items are always purchased (NU) while others go through a rental-to-purchase conversion after a set number of months. The modifier affects how Medicare reimburses the claim.
Q: How do you verify coverage for a DME item before billing?
A: First check for a National Coverage Determination (NCD) from CMS, which applies nationwide. If no NCD, check the LCD (Local Coverage Determination) from the DME MAC that covers the patient's zip code. The LCD specifies the ICD-10-CM codes that support medical necessity. If the patient's diagnosis is not on the LCD, coverage is unlikely and an ABN should be obtained before providing the item.
Q: What is PDAC and when do you use it?
A: PDAC stands for Pricing, Data Analysis and Coding — a contractor that helps verify the correct HCPCS code for DME items, prosthetics, and orthotics. You can submit a product classification request to PDAC to confirm which HCPCS code applies to a specific product. This is important for complex wheelchair systems and custom orthoses where code selection significantly impacts reimbursement.
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