CPST Capstone Turbine Corporation

(818) 734-5300

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Explanatory Note

On October 18, 2016, Capstone Turbine Corporation (the “Company”) filed a Current Report on Form 8-K (the “Original Form 8-K”) with the Securities and Exchange Commission (“SEC”) to report, among other things, the entry into a securities purchase agreement with certain accredited investors (the “Purchasers”), pursuant to which the Company agreed to sell to the Purchasers (i) in a registered offering, 3,600,000 shares of the Company’s common stock, $0.001 par value per share (“Common Stock”), and pre-funded Series B warrants to purchase up to 2,700,000 shares of Common Stock, which will be sold in lieu of Common Stock to those Purchasers whose purchase of Common Stock in the offering otherwise would result in the purchaser beneficially owning more than 9.99% of the Company’s outstanding Common Stock following the completion of the offering; and (ii) in a concurrent private placement, Series A warrants to purchase up to 6,300,000 shares of Common Stock.

The purpose of this Current Report on Form 8-K is to file with the SEC, as contemplated by the Original Form 8-K, Exhibits 1, 4.1, 4.2, 5, 10, and 23 hereto.