In regards to the CMS 14 day rule for lab test date of service.
For inpatients, all services are bundled to the DRG, unless tests are ordered more than 14 days after inpatient discharge.
for outpatients, lab tests services are variably bundled or separately payment. Billing staff don't need to guess. CMS gives a "Status Indicator" or "SI" for every CPT code that tells if it is nonpayable, bundled, conditionally bundled, etc.
For regular clinical chemistry, the SI is usally Q4 meaning the service is bundled if there is anything to bundle it to (like an outpatient visit or outpatient surgery). If the patient had no service but a blood draw, there's nothing to bundle it to so the Q4 clinical chemistry is billable.
For "molecular pathology," CMS defines this not in writing but in practice. In practice, CMS generally gives human DNA and RNA tests status A, meaning separately payable.
(CMS also gives status A to a couple very rare categories of test I will ignore here.)
For anatomic pathology including IHC, most codes have status Q1. Q2. This means in the outpatient setting they are bundled to procedures (e.g. surgeries) if one occurred. (But the pathologist's interpretation fee, often around $20, is payable).
Where to Find It
The CPT code list and Status Indicators are discussed as need in the annual summer outpatient rulemaking. The code list, Addendum B, is updated every quarter all year.
Find the updates here:
Examples.
80047, 80051 Basic chem panels, Q4, bundled if there is any event (office visit) to bundle to
Pathogen tests, although "molecular" DNA, RNA, are BUNDLED Q4 because not human DNA, RNA.
Anatomic pathology codes are generally bundled, assuming there is a procedure to bundle them to, via Q1 or Q2.
