Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

FIDELITY ABERDEEN STREET TRUST

Prospectus Date

rr_ProspectusDate

Jul. 30, 2014

A T C | Fidelity Advisor Freedom 2060 Fund

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

fast_SupplementTextBlock

Supplement to the
Fidelity Advisor Freedom^® 2060 Fund
Class A, Class T, and Class C
July 30, 2014
Prospectus

Notwithstanding any information in the prospectus to the contrary, effective on or about August 1, 2014 Strategic Advisers, Inc. may vary asset allocations within the asset classes identified in the prospectus (domestic equity funds, international equity funds, bond funds and short-term funds) from the target asset allocations in each fund's fund summary. Strategic Advisers may utilize this strategy to allow portfolio managers to express their cyclical asset class views within predefined risk parameters. In implementing this strategy, Strategic Advisers, Inc. may vary exposure to asset classes as follows:

Asset Class	Range
Equity Funds (domestic and international)	+/- 10% (aggregate limit)
Bond Funds	+/- 10%
Short Term Debt Funds	+/- 10%

The following information supplements information under "Principal Investment Risks" in the "Fund Summary" section and the "Investment Details" section of the prospectus.

Active Allocation Risk. Strategic Advisers has discretion to increase or decrease the exposure to the asset classes listed above. This strategy may not be successful in adding value, may increase losses to the Fund and/or cause the Fund to have a risk profile different than that portrayed above from time to time.