Physicians who refer or order services for Medicare patients must be enrolled in PECOS, the Medicare Provider Enrollment, Chain, and Ownership System database, and physicians who bill Medicare are required to list the name and National Provider Identifier (NPI) of the ordering/referring physician on their claims in order to be paid.  The source of these requirements is Section 6405 of the Affordable Care Act. CMS is about to implement an automatic edit so that claims submitted on or after May 1st for certain services ordered by a physician or healthcare provider who is not enrolled in PECOS, even if his or her name and National Provider Identifier (NPI) are on the claim, will be denied.  This change may affect a relatively small but important set of anesthesiologists, who have raised questions about the issue.  As part of the pre-operative evaluation of surgical patients, anesthesiologists may order clinical laboratory or even imaging...