Tesla will be dropping the Model S 60 and 60 D next month. According to Electrek, Tesla sent out emails to potential buyers last week letting them know that they have until April 16th to place an order for the 60.
The 60-kWh version of the Model S was an odd model since it was equipped with a 75kWh battery pack that was limited via software to act like a smaller battery. Tesla offered the ability to unlock the full capacity of the battery for only $9.500.
Tesla confirmed this and explained the reason they are dropping the 60 is most buyers tend to go for the battery upgrade and they want to streamline the ordering process.