company founder, purchases stock in the company at nominal price shortly after the company is formed. The company retains a repurchase right to buy the stock back at the same price should the employee leave. The repurchase right diminishes over time so that the company eventually has no right to repurchase the stock (in other words, the stock becomes fully vested). Beginning in the 1990s, vesting periods in the United States are usually 3–5 years for employees, but shorter for board members and others whose expected tenure at a company is shorter. The vesting schedule is most often a pro-rata monthly vesting over the period with a six or twelve month cliff. Alternative vesting models are becoming more popular including milestone-based vesting and dynamic equity vesting. In the case of both stock and options, large initial grants that vest over time are more common than periodic smaller grants because they are easier to account for and administer, they establish the arrangement up-front and are thus more predictable, and (subject to some complexities and limitations) the value of the grants and holding period requirements for tax purposes are set upon the initial grant date, giving a considerable tax advantage to the employee. Profit sharing plans Profit-sharing plans are usually vested in ten years, although in some cases a plan may serve essentially as a pension by allowing a limited amount of vesting should the employee retire or leave on good terms after an extended period of employment. Vested rights doctrine in zoning law The vested rights doctrine is the rule of zoning law by which an owner or developer is entitled to proceed in accordance with the prior zoning provision where there has been a substantial change of position, expenditures, or incurrence of obligations made in good faith by an innocent party under a building permit or in reliance upon the probability of its issuance. Vesting arrangements and terminology A "vesting period" is a period of time an investor or other person holding a right to something must wait until they are capable of fully exercising their rights and until those rights may not be taken away. In many cases vesting does not occur all at once. Specific portions of the rights grant vest on different dates over the duration of the period of the vesting. When part of a right is vested and part remains unvested, it is considered "partly