I found a Pink Sheet that reiterates the same...
When an orthopedic surgeon performs a second diskectomy on a patient who has reherniated the nucleus pulposus at the same level, CPT directs your coders to use reexploration laminotomy code 63042.
CPT Changes: An Insider's View 2001 states: "Codes 63040-63044 are the only codes that may be reported for procedures performed on a recurrent herniated nucleus pulposusat each previously explored cervical or lumbar interspace. The term ‘reexploration' simply relates to the repeat surgical exposure of a previous surgical tract and target at the same site on the same patient at a time after an initial surgical procedure(s) was performed. As with other CPT code descriptors, the timeframe associated with the reexploration procedure is not specifically stated." (emphasis added).
In other words, whether it occurs during or following the 90-day global period for the original laminotomy, use code 63042. The North American Spine Society (NASS) publication, 2009 Common Coding Scenarios, confirms this guidance: "Code 63042 is recommended for use when there is recurrent herniated disc requiring excision." Append modifier 78 if reexploration occurs within the global period.
When HNP recurrence occurs at multiple levels, you may use add-on codes 63043 (each additional cervical interspace) or 63044 (each additional lumbar interspace). So, make sure your physicians know it's important they document precisely the levels at which the diskectomy is performed.