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How many warheads were allowed under the final phase of START I?

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Strategic Arms Reduction Talks U.S. Pres. Barack Obama talking with Russian Pres. Dmitry Medvedev, just before the two leaders issued a joint statement about their continued cooperation on the New START Treaty, December 4, 2009.

Under the Strategic Arms Reduction Talks (START I) treaty, the reduction of nuclear warheads was structured in three distinct phases. The final phase, which was to be completed by the end of 2001, required both the United States and Russia to reduce their arsenals to a limit of 6,000 warheads on a maximum of 1,600 delivery vehicles.1

Within these final limits, no more than 4,900 of those warheads could be mounted on deployed intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs). Both nations successfully enacted these cuts by the 2001 deadline.1