Anesthesia Services furnished in conjunction with and in support of a screening colonoscopy are reported with CPT code 00812.  CPT code 00812 will be part of the January 1, 2018 update and will waive cost share.  When a screening colonoscopy becomes a diagnostic colonoscopy, anesthesia services are reported with CPT code 00811 and with the PT modifier.  CPT code 00811 will be added as part of the January 1, 2018 update.  Medicare will pay claims with new code 00811 and waive only the deductible (if applicable) when submitted with the PT modifier.

https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNMattersArticles/downloads/MM10181.pdf