I\u2019m a big believer in having the appropriate amount of insurance, especially when it comes to your health and personal liability. But if money is tight and you want to get the most bang for your buck, there are a few types of insurance you can probably do without \u2014 or that may duplicate coverage you already have elsewhere. Extended warranties When you buy a car, appliance or electronic device, the sales clerk usually will try to sell you an extended warranty. These policies often duplicate coverage already provided in the manufacturer\u2019s warranty. Plus, many credit cards provide an additional warranty on items purchased with the card. Smartphone insurance After shelling out big bucks for a smartphone, you might be tempted to buy replacement insurance. Just be aware that you\u2019ll probably pay a hefty deductible and likely receive a refurbished phone, possibly not even the same model. My advice: Keep your old phone to reactivate in case you drop or lose the new one. Flight accident insurance The risk of dying in a plane crash is minuscule and already covered by regular life insurance. Also check your credit card cardholder agreement, since many cover such accidents for tickets purchased with their card. Child life insurance Life insurance is intended to provide economic protection for a person\u2019s dependents, so unless your children are movie stars supporting you, this coverage is probably unnecessary. You can better protect their future by stowing those monthly premiums in an emergency savings account or buying additional term life insurance for yourself. Pet insurance With veterinary treatments now rivaling human medicine (organ transplants, chemotherapy, etc.), you could easily spend a small fortune keeping Fido alive. Before buying pet insurance, however, compare plan features carefully and weigh the expense you\u2019d pay out over your pet\u2019s lifetime. For example, monthly premiums increase with your pet\u2019s age, deductibles and co-payments are typically higher than for human coverage, and there are usually predetermined per-year and per-condition caps. Plus, pre-existing and hereditary conditions usually are not covered. Rental car insurance In most cases, the optional insurance offered by car rental agencies duplicates existing coverage you already have. However, before automatically rejecting agency coverage, ask your insurance company and credit card issuer whether you are fully covered for rental cars. A few considerations: \u2014Coverage through your auto policy often expires after 30 days or less of renting the car. \u2014Sports cars, luxury models, SUVs and trucks often are excluded. \u2014Travel outside service areas typically is forbidden \u2014 especially across foreign borders or in rough terrain. \u2014If you don\u2019t carry comprehensive and collision coverage on your own car, your insurance may not cover a rental. Also, ask whether such coverage is limited to your own car\u2019s value, since most rentals are new. \u2014Ask what happens if you violate rental agreement terms (e.g., driving recklessly or allowing unauthorized drivers). Specified disease insurance Some people take out supplemental health and life insurance against specific conditions such as cancer, heart disease or stroke. Before buying, make sure you have adequate major medical insurance, which already covers such conditions. And carefully review the policy for restrictions. For example, many cancer insurance policies won\u2019t pay for outpatient care or cover skin cancer, and impose fixed-dollar limits on specific procedures. When it comes to your budget \u2014 and your family\u2019s security \u2014 it pays to know which insurance is essential and which you can probably skip. Jason Alderman directs Visa\u2019s financial education programs. To participate in a free, online Financial Literacy and Education Summit on April 17, go to www.practicalmoneyskills.com\/summit2013.