Parking mandates or parking requirements are policy decisions, usually taken by municipal governments, which require new developments to provide a particular number of parking spaces.

Parking minimums were first enacted in 1950s America during the post-war construction boom with the intention of preventing street parking from becoming overcrowded. Requirements vary based on the type and usage of the building, with some typically being one parking spot per apartment, 300 square feet of retail or commercial space, 100 square feet of restaurant dining area, two hospital beds, or five seats in a church's pews.

Parking minimums typically lead to an oversupply of parking relative to what the market would supply in the absence of the minimums. They also provide an implicit subsidy to drivers by making parking spaces more abundant. Parking minimums have shifted the cost of parking spaces from drivers to building developers, making them a hidden cost ($28,000 for non-garage, $56,000 for garage spaces, excluding the cost of land) that thereby increases the cost of rents by nearly 20%, and has contributed to America's housing affordability problem. The oversupply of parking contributes to lower housing densities and reduced walkability. As a consequence, local and state governments have increasingly in recent years reduced or eliminated parking minimums or enacting parking maximums for new developments. When parking mandates for new housing construction are reduced or eliminated, substantial increases in housing supply occur.

The first parking minimums in the United States were implemented by Columbus, Ohio, in 1923.

In North America, parking minimums are requirements, as dictated by a municipality's zoning ordinance, for all new developments to provide a set number of off-street parking spots. These minimums look to cover the demand for parking generated by said development at the peak times. Thus different land uses, whether they be commercial, residential or industrial, have different requirements to meet when deriving the number of parking spots needed. For example, the City of Los Angeles requires churches to build one parking space for every five seats in the pews, and hospitals to build two per bed.

U.S. cities use Parking Generation Rates, a guidebook of statistical data from the Institute of Transportation Engineers, to source parking minimums. In these reports, the ITE define a type of land use's Parking Generation through an observational study. Parking Generation is found by the land uses, average generation rate, the range of generation rates, the subsequent standard deviation, and the total number of studies. This process is done by various studies to find the range. In the case of ITE studies, the observation of a single site multiple times is considered a stand-alone study. Then the average of the range is used to determine the average parking generation rate of a land use. This handbook is updated every 5 years to determine the demand for parking for specific land uses. Parking Generation Rates provided by the ITE doesn’t explicitly state what parking minimums should be, but rather is just a collection of statistical data for urban planners to interpret and use for at their own volition. Regardless, ITE's Parking Generation has been an influential factor in most North American cities in the adoption parking ratios, according to land use, to determine the minimum spots required by new developments.

Parking Generation, regardless of its widespread use in North American cities, is disputed as a tool to determine parking minimums due to its questionable statistical validity. Statistical significance is a major qualm with Parking Generations due to the oversimplification of how the parking generation rate is derived. Peak parking observed by ITE doesn’t take into account the price of parking in relation to the number of parked cars. Thus the demand at any given time for parking is always high because it is oversupplied and underpriced, resulting in an inflated calculation for the parking generation rate of a land use. Parking minimums also often fail to take into account nearby parking, requiring businesses with peak patronage at different times of day to build out the largest possible lots.

Donald Shoup, a UCLA urban planning professor who pioneered the field of parking research, has called parking minimums a "pseudoscience", as the ITE's calculations are typically based on minimal data and approximations that cannot be widely applied to other businesses, even of the same type. Many businesses have been forced to build parking lots that are never full even on the busiest days. Before it eliminated parking minimums for new developments in 2022, San Jose, California, had a requirement for bowling alleys have seven parking spots per lane, assuming that all would be in use by a full party that all drove separately. For the broad use of "Recreation, commercial (indoor), the city required one parking spot per 80 square feet of recreational area, regardless of the expected number of users coming by car. A restaurant had to build a parking lot eight times the size of the restaurant itself.