Yes, all new A2 Hosting accounts support Let's Encrypt.
Using an SSL certificate from a recognized Certificate Authority is recommended for best results when enabling SSL. Let’s Encrypt is a free, automated, and open Certificate Authority, and is recognized by most modern browsers. Let's Encrypt is supported for all new A2 Hosting accounts and certificates may even be generated automatically for immediate use.
Shared and Reseller accounts have Let's Encrypt enabled by default.
Managed VPS and Dedicated accounts may request installation and activation from support.
Let's Encrypt may be installed and configured on Core and Unmanaged products by the user.
For details regarding Let's Encrypt for your account type, please see the Related Articles below.