A new annuity known as “longevity” insurance is attracting some attention. In just six months, New York Life Insurance Co.’s deferred income annuity surpassed $230 million – 10 times the company’s sales goal. A longevity policy converts a lump sum into a pension-like stream of income for life and set to start at a future date. Knowing when payments will begin can allow a higher withdrawal from savings earlier in retirement. In February, the Treasury Department issued a proposal to make it easier to buy such a policy in 401(k)s and IRAs. Downsides to a longevity policy include surrendering the principal to the insurer, missing out on higher returns from the stock market, and the fact that the purchasing power of the annuity payments will be reduced if inflation increases.