CMS has announced final approval of revised versions of the Medicare Provider-Supplier Enrollment Applications (CMS-855).  While the revised forms may be used immediately, the previous 2008 versions may be used through October 2011. In addition, CMS has released a new CMS-855O application form to be used for the sole purpose of enrolling to order and refer items and/or services to Medicare beneficiaries; this form must be used immediately.