This comes straight from the AAPC Steps To Remove Your -A:
To remove your apprentice designation via on-the-job experience, you must obtain and submit two letters of recommendation verifying at least two years of on-the-job experience (externships accepted) using the CPT®, ICD-9-CM, or HCPCS Level II code sets. One letter must be on letterhead from your employer*, the other may be from a co-worker. Experience includes time coding for a previous employer and prior to certification. Both letters are required to be signed and will need to outline your coding experience and amount of time in that capacity. Download our Apprentice Removal Template for easier submission. Letterhead and signatures are still required when using this template.
OR
Submit proof showing completion of at least 80 contact hours of a coding preparation course (not CEUs) AND one letter, on letterhead, signed from your employer verifying one year of on-the-job experience (externships accepted) using the CPT®, ICD-9-CM, or HCPCS Level II code sets.
Send proof of education in the form of a letter from an instructor on school letterhead stating you have completed 80 or more contact hours, a certificate/diploma stating at least 80 contact hours, or an unofficial school transcript.
Hope this helps.
Aaron K