The answer to this question will depend on the preferences and circumstances of each individual.
As your assets grow and your financial picture becomes more complex (with unclear tax implications, and interdependent asset classes), then the answer is more likely to be yes. For those investors with a more modest-size portfolio, it may not be necessary.
Financial modeling tools and market research publications are widely available, and while they are not one-size-fits-all answers, they can serve investors quite well when used wisely. Investors who choose not to consult an advisor must be willing to educate themselves.
Many related questions and concerns are addressed in these Forums and articles, where you will find guidelines to help you decide if a financial advisor is right for you.
Where do I find a Financial Advisor?
How Fast Should My Portfolio Grow?
Value mutual funds are those that invest in companies with strong fundamentals and steady earnings histories
A covered call is when the writer or seller of a call option either owns the underlying security, or has a guarantee
A SIMPLE IRA must be established by an employer with fewer than 100 employees
A 457 is only slightly different than a 401(k), but the differences can be important
A Thrift Savings Plan (TSP) is a 401(k)-style plan for Federal employees. A TSP functions the same way a 401(k) does
Weighted Average Market Capitalization is a method which gives market cap, for a company, greater weight
Credit debt or credit card debt is a type of consumer debt that is incurred through a short-term revolving loan facility
The Foreign Credit Insurance Association protects American businesses from non-payment in international trade deals
Realistically, you should not plan on getting more that about 10% average per year over the long term for a portfolio...