15 USC 80b3a - State and Federal responsibilities

(a) Advisers subject to State authorities 

(1) In general 
No investment adviser that is regulated or required to be regulated as an investment adviser in the State in which it maintains its principal office and place of business shall register under section 80b–3 of this title, unless the investment adviser
(A) has assets under management of not less than $25,000,000, or such higher amount as the Commission may, by rule, deem appropriate in accordance with the purposes of this subchapter; or
(B) is an adviser to an investment company registered under subchapter I of this chapter.
(2) “Assets under management” defined 
For purposes of this subsection, the term assets under management means the securities portfolios with respect to which an investment adviser provides continuous and regular supervisory or management services.
(b) Advisers subject to Commission authority 

(1) In general 
No law of any State or political subdivision thereof requiring the registration, licensing, or qualification as an investment adviser or supervised person of an investment adviser shall apply to any person
(A) that is registered under section 80b–3 of this title as an investment adviser, or that is a supervised person of such person, except that a State may license, register, or otherwise qualify any investment adviser representative who has a place of business located within that State; or
(B) that is not registered under section 80b–3 of this title because that person is excepted from the definition of an investment adviser under section 80b–2 (a)(11) of this title.
(2) Limitation 
Nothing in this subsection shall prohibit the securities commission (or any agency or office performing like functions) of any State from investigating and bringing enforcement actions with respect to fraud or deceit against an investment adviser or person associated with an investment adviser.
(c) Exemptions 
Notwithstanding subsection (a) of this section, the Commission, by rule or regulation upon its own motion, or by order upon application, may permit the registration with the Commission of any person or class of persons to which the application of subsection (a) of this section would be unfair, a burden on interstate commerce, or otherwise inconsistent with the purposes of this section.
(d) State assistance 
Upon request of the securities commissioner (or any agency or officer performing like functions) of any State, the Commission may provide such training, technical assistance, or other reasonable assistance in connection with the regulation of investment advisers by the State.