Medicaid Health Opportunity Account Act of 2005

Medicaid Health Opportunity Account Act of 2005 - Amends title XIX (Medicaid) of the Social Security Act to direct the Secretary of Health and Human Services to establish a demonstration program under which states may provide alternative benefits, including health opportunity accounts, for eligible population groups in one or more geographic areas.

Prohibits the Secretary from approving a state demonstration program unless it provides for transactions involving health opportunity accounts to be conducted electronically and without cash.

Limits contributions into a health opportunity account to those by: (1) the state under Medicaid; and (2) other persons and entities, such as charitable organizations.

Requires a state to specify the contribution amount that shall be deposited into a health opportunity account.

Allows a state to: (1) impose limitations on the maximum contributions that may be deposited into a health opportunity account in a year; and (2) limit contributions into such an account once the balance reaches a specified level.

Prohibits a state from contributing annually to a health opportunity account, on behalf of an individual or family, more than $2,500 per adult and $1,000 per child.

Allows the use of amounts in a health opportunity account for payment of such health care expenditures as the state specifies.