National Wildfire Infrastructure Improvement and Cost Containment Act

National Wildfire Infrastructure Improvement and Cost Containment Act - Amends federal civil service law to raise the age for mandatory separation of a wildland firefighter from 57 to 65 years of age, or until her or she is certified by a licensed physician as being unable to successfully complete all applicable physical standards testing. Prohibits the use of funds appropriated to a federal department or agency to contract for the performance of firefighting or security guard functions that are performed, as of this Act's enactment, by a federal employee of any such department or agency.

Directs the Office of Personnel Management (OPM), in cooperation with the federal land management agencies, to commence development of a separate wildland firefighter occupational series that will more accurately reflect the variety of duties performed by wildland firefighters.

Requires a wildland firefighter's hours of work officially ordered or approved in excess of 40 hours per week or 8 hours per day to be considered overtime work. Makes time the firefighter is away from his or her official duty station assigned to an emergency incident, in support of an emergency incident, or pre-positioned for emergency response, compensable as work time. Includes hazardous duty differentials as basic pay for retirement purposes.

Prohibits OPM from excluding wildland firefighters from government employees' life insurance coverage. Permits, under specified circumstances: (1) the continuation of health benefits for a wildland firefighter between wildfire seasons; and (2) anyone subject to the Federal Employees Retirement System (FERS) as a firefighter to have any qualifying firefighter service treated as creditable service, regarding service performed between 1989 and this Act's enactment. Provides for investigations of firefighter fatalities by the Inspectors General of the Departments of Agriculture and the Interior. Repeals a requirement for an independent investigation of Forest Service firefighter deaths caused by wildfire entrapment or burnover.