Improper Payments Agency Cooperation Enhancement Act of 2014 - (Sec. 2) Amends title II (Old Age, Survivors, and Disability Insurance Benefits) of the Social Security Act to direct the Commissioner of the Social Security Administration (SSA) to: (1) provide information on all deceased individuals that is furnished to or maintained by the Commissioner, subject to appropriate safeguards against unauthorized use or disclosure, to federal or state agencies providing benefits or administering a federal program; and (2) provide for the use of such information by federal agencies to operate the Do Not Pay working system and to carry out tax administration or debt collection duties.

Requires the Director of the Office of Management and Budget (OMB) to analyze and report to Congress on potential alternative sources of death data maintained by non-federal sources.

(Sec. 3) Requires the Secretaries of State and Defense, in coordination with the SSA Commissioner, to establish a procedure for submitting to the Commissioner information on the deaths of individuals.

Requires the OMB Director to: (1) issue guidance to agencies that operate or maintain a database of information relating to beneficiaries, annuity recipients, or other purposes for which improved data matching with databases would be relevant and necessary; (2) develop a plan to assist states and local agencies, and Indian tribes and organizations, to provide information, in an electronic format, to the federal government on the deaths of individuals; and (3) submit to Congress a plan to improve data matching with the federal government on the death of individuals who are benefit recipients and to submit an annual report on the implementation of such requirements.

(Sec. 4) Extends the availability of the Do Not Pay Initiative to the legislative and judicial branches and to the states.

(Sec. 5) Requires the Secretary of the Treasury to report to Congress on: (1) data analytics performed as part of the Do Not Pay Initiative to prevent and recover improper and duplicative payments, and (2) the metrics used in determining whether analytic and investigatory efforts have helped to reduce improper payments or awards.

Improper Payments Agency Cooperation Enhancement Act of 2013 - Amends the Improper Payments Elimination and Recovery Improvement Act of 2012 to require the Commissioner of the Social Security Administration (SSA) to: (1) establish and maintain the National Deaths Registry to provide information relating to the deaths of individuals for the purpose of supporting the Do Not Pay Initiative and otherwise preventing, identifying, or recovering improper payments; (2) enter into cooperative agreements with federal agencies, including Inspectors General, and states, local and tribal governments to provide information in the Registry to such agencies and entities to prevent and recover improper payments; and (3) implement procedures for identifying and correcting errors in the Registry.

Directs the Director of the Office of Management and Budget (OMB) to identify each agency that operates or maintains a database relating to federal beneficiaries and annuity recipients. Requires each agency to establish: (1) a data matching procedure to compare agency information with information in the Registry, and (2) a procedure for prompt reporting to the Commissioner of information relating to the death of a recipient of federal benefits or a retirement annuity.

Directs the Secretary of the Treasury to report to Congress on data analytics performed as part of the Do Not Pay Initiative and the metrics used in determining whether the analytic and investigatory efforts have reduced improper payments or awards.

Directs OMB to convene a task force of agencies to: (1) identify ways to improve the sharing of information relating to deaths of individuals receiving a federal retirement annuity, (2) share best practices for identifying deceased annuitants, and (3) report to Congress on such efforts.

Requires the U.S. Postal Service (USPS) to provide agencies access to information on delivery addresses, including Commercial Mail Receiving Agency lists of known locations of commercial mail boxes, for purposes of improved detection, prevention, and recovery of improper payments.