No. It is not a pension.
TSP is a retirement savings plan that has costs and risks and must be managed.
How is TSP different from a pension?
An individual-account retirement savings plan like the Thrift Savings Plan differs from most other kinds of pensions in several ways, including:
What are some similarities between a pension and TSP?
Contributions to a Thrift Savings Plan are made by the employee and matched by the government. Unlike pensions, withdrawals from the plan must begin at age 70.