The IRS Form CP575 is the IRS generated letter you receive from the IRS granting your Employer Identification Number.
For copy you need contact IRS via the phone. Call 1-800-829-4933 from 7:00 a.m. to 10:00 p.m.
Please let me know if you need any help.
To change your address with the IRS, you may complete a Form 8822 , Change of Address, and send it to the address shown on the form.
You are correct - the IRS will not re-issue or provide a copy of the CP-575 Letter.
If you lost your original letter and need to confirm your EIN - the IRS will send you the letter 147-C that may be used when you are asked for the CP-575 Letter.
You also may use letter 147-C to obtain the Medicare Provider number.
You may send a written request for the letter 147-C - but that would be faster to call and request on the phone.