If you're wondering how to pay your Medicare enrollment or revalidation fee under new application fee rules, you now have an answer. A $505 fee is required for applications received March 25 or after, CMS notes in a new MLN Matters article. Providers must pay the fee through pay.gov. Tip: Providers can apply for a hardship exception from the fee, but the exception letter must accompany the 855 application, CMS instructs. The MLN Matters article, which also covers changes such as screening categories and moratoria, is at www.cms.gov/MLNMattersArticles/downloads/MM7350.pdf.