Ensuring Military Readiness Act of 2023 This bill requires the Department of Defense (DOD) to prescribe regulations regarding military service by transgender individuals. The regulations must disqualify transgender individuals with a history or diagnosis of gender dysphoria from military service, with some exceptions. (DOD has defined gender dysphoria as a marked incongruence between one's own experienced gender and assigned gender.) The regulations must provide exceptions for such individuals if they have been stable for 36 consecutive months in their biological sex prior to accession; or diagnosed with gender dysphoria after entering into service and do not require a change of gender and remain deployable. Under the regulations, members of the Armed Forces who have been diagnosed with gender dysphoria may continue to serve in their current gender and receive medically necessary treatment for gender dysphoria. However, such treatment may not include gender reassignment surgery or the commencement of hormone therapy. Transgender individuals who require or have undergone gender transition are disqualified from military service. Additionally, transgender individuals who do not have a history or diagnosis of gender dysphoria and are otherwise qualified for service may serve in the Armed Forces in their biological sex.