Image source: SSA.

Social Security is a key program that tens of millions of Americans use to support themselves in retirement. It's important in doing your financial planning to know whether you'll be eligible to receive Social Security. Below, you'll find a brief primer on whether you can get various types of benefits.

Regular retirement benefits
If you're a worker looking to claim retirement benefits based on your own work record, then the key question for eligibility is whether you've earned enough credits under the Old Age and Survivors Insurance program. A minimum of 40 credits is necessary to claim Social Security retirement benefits. Workers can earn up to four credits a year, and in 2016, you'll receive one credit for every $1,260 in annual earnings you have up to the four-credit maximum. Once you're eligible, you can take retirement benefits as early as age 62.

Spousal benefits
Social Security is also available to spouses of workers who qualify. Spouses don't need work credits of their own, but they do have to have been married to the worker for a minimum of one year. Divorced spouses are also entitled to spousal benefits if their marriage lasted at least 10 years and the person seeking spousal benefits hasn't remarried.

The age of claiming spousal benefits depends on family history. Age 62 is the typical minimum age, but younger spouses who are caring for children under age 16 who also receive Social Security benefits can claim spousal benefits. One key, though, is that the worker typically has to file for retirement benefits before a spouse can file for spousal benefits on that record. In some cases, that can extend the minimum age beyond 62 for older spouses filing for spousal benefits.

Children's benefits
Certain children of qualifying workers can also claim Social Security benefits. To qualify, children have to be under age 18 or be in high school and no older than 19. Benefits for most children stop when they turn 18 or graduate from high school, whichever is later, as long as graduation occurs before age 19 and two months.

Disabled children are entitled to lifelong benefits regardless of age. The key, though, is that the disability must have started before the child reached age 22.

Survivor benefits
The eligibility rules for survivor benefits are different, because in many cases, they are payable because a worker didn't live to full retirement age. The number of work credits depends on the age of the death of the worker, running from as little as six credits over the most recent three years. Having 40 credits will always be adequate to give full survivor benefits to your family.

Eligible survivors include surviving spouses and qualifying children. To be eligible, a surviving spouse must have been married to the deceased spouse for at least nine months or qualify for an exception for accidental death, death in the line of military duty, or having a child with the deceased spouse. Age 60 is the usual minimum age for widows and widowers, but caring for a child under 16 who is also eligible for benefits can get rid of the age requirement. Remarriage after age 60 does not take away survivor benefits.

Children can qualify for survivor benefits if they meet the same requirements as for children's benefits above. The same age limits apply to children who are not disabled.

Social Security is an essential financial support mechanism for American retirees and their families. Knowing whether you qualify is a key factor in making the best possible choice with your Social Security benefits.