PTAN (Provider Transaction Access Number) is a unique identifier assigned by the Centers for Medicare & Medicaid Services (CMS) to healthcare providers who have enrolled in Medicare. 

To verify that a medical supplier has an active PTAN number without any ongoing investigations, a consumer can follow these steps: 

• Go to the CMS website: The first step is to visit the CMS website at www.cms.gov. 
• Click on the “Tools” tab: Once on the CMS website, click on the “Tools” tab located on the top navigation bar. 
• Click on “Medicare Enrollment and Provider Lookup”: From the “Tools” tab, select “Medicare Enrollment and Provider Lookup.” 
• Search for the supplier: Enter the name or NPI (National Provider Identifier) of the medical supplier you want to verify in the search bar and click “Search.” 
• Check the PTAN status: Once the search results appear, look for the supplier’s PTAN number and make sure it is listed as “Active.” 
• Check for ongoing investigations: While on the search results page, check for any ongoing investigations or sanctions against the supplier. If there are none, then the supplier is likely in good standing with CMS. 

By following these steps, a consumer can verify that a medical supplier has an active PTAN number without any ongoing investigations. However, it’s important to note that the absence of any ongoing investigations or sanctions does not necessarily guarantee the quality of the medical supplier’s services, and consumers should still exercise caution and do their due diligence before choosing a healthcare provider.