If you are one of those people who hate to make decisions, November will not be a fun month. But two hunting seasons -- for health insurance and investment opportunities -- that begin shortly are vital to members of the federal family.

One of the decision periods deals with investments and long-range financial commitments. What you do now could make the difference between having a comfortable retirement (or a nest egg when you leave the government) or just getting by in what are supposed to be your golden years.

This month's second hunting season concerns health insurance coverage. What you do could make the difference between a comfortable year, and a period of heavy unexpected medical bills. Here's a preview:

From Nov. 15 through Jan. 31, federal workers will have an opportunity to sign up for, or make changes in, investment options in the thrift savings plan.

The plan is an optional part of the federal retirement program. It allows workers to allocate from 5 percent to 10 percent of their salary to be invested in a tax-deferred savings and investment program that is almost identical to 401(k) plans available in the private sector.

The plan is open only to people who are working for the government. Retirees cannot invest in it.

Workers under the Civil Service Retirement System can invest up to 5 percent of their pay in the savings plan. Those under the Federal Employees Retirement System can invest up to 10 percent of pay and get a government match of up to 5 percent, which is also tax-deferred.

Starting next year, workers can invest in any or all of the savings plan options. One fund is invested in Treasury securities, another is tied to the stock market and the other invests in the bond market.

To sign up for the savings plan, workers would need to get a TSP-1 form from their agency benefits office. To reallocate funds already invested, they would need a TSP-30 form.

From Nov. 13 through Dec. 10, federal workers and retirees must pick their 1991 health plan.

They will receive plenty of help from various publications, including the "Open Season Guide" by Employee Benefits Review and "Checkbook's Guide to Federal Employee Health Plans" by the Washington Consumers Checkbook.

The Federal Times newspaper and The Washington Post Health section will have special guides. We will have the usual series of columns here about the best buys for singles, families, retirees and people with specific medical problems.

The current issue of Retirement Life, the magazine of the National Association of Retired Federal Employees, has an excellent detailed guide to federal health plans, benefits and premiums.

Getting through the open seasons will be a pain in the neck for some people. But ignoring either one could be a costly mistake.