Recent changes in the state Medicaid coverage will allow all Medicaid-eligible adults to obtain hearing aids, cochlear implants, or other oseointegrated heating devices. The changes that went into effect in October of 2018 were on WTOP on January 9, 2019. 

Previously such coverage was limited to children and adults under the age of 21. It is also noteworthy that the process of determining candidacy and procuring the appropriate treatment starts with the PCP but explicitly involves the audiologist. 

Reference

Moore J. (2019) Hearing aids for all adults now covered under Maryland Medicaid. WTOP. January 9.